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A new study on effect of various chemical treatments on Agave Americana fiber for composite reinforcement: Physico-chemical, thermal, mechanical and morphological properties
Abstract
This research is focused to fundamentally understand the benefits of using Agave Americana C. plant as potential reinforcement in polymeric composites. The fibers were extracted from the external part of the bark of the plant, which grows worldwide in pastures, grasslands, open woodlands, coastal and riparian zones. In order to use the natural fiber as reinforcement it is paramount important to probe their chemical composition, microstructural behavior and mechanical properties. Hence, firstly the extracted fibers were chemically treated with NaOH, stearic acid, benzoyl peroxide and potassium permanganate. The chemical composition in terms of cellulose, hemicellulose, lignin and other waxy substances were determined using a standard TAPPI method. FT-IR technique was used to understand the character of molecular bonds, crystallinity and their correlations with various bonds in fiber structure. The thermal stability was investigated through thermogravimetric and differential scanning calorimetric analysis, and the mechanical characterization was performed by applying standard tensile test. The surface morphology of fibers was examined through scanning electron microscopy (SEM) and finally reliability scrutiny of all the analysis was carried out. The results of chemical modification techniques applied on the surfaces of natural fibers allows to produce superior fibers used to form the novel composite materials for light-weight application.
... Essas medidas foram realizadas em três repetições para cada amostra. A percentagem de perda por dessecação foi obtida pela Equação 1: Madhu et al. (2020) obteve teor de umidade de 9,32% em fibras de sisal natural e 8,02% fibras tratadas com hidróxido de sódio, podendo considerar que a fibra de sisal tem valores próximos de teor de umidade que outras fibras de sisal citadas acima. Para o teor de cinzas Figura 4 foram encontrados os valores de 1,93% para fibras não tratadas e 1,11% para fibras tratadas por hornificação. ...
... Os teores são menores do que os reportados na literatura por Madhu et al. (2020), que obteve 3,29% para fibra in natura e 4,43% para fibras tratadas com hidróxido de sódio. Observase que o teor de cinzas foi reduzido após o tratamento por hornificação, o que sugere a remoção de parte dos compostos inorgânicos presentes na superfície das fibras, já que se trata de um tratamento físico. ...
... Além disso, o método de preparação e análise das fibras pode ter influenciado os valores obtidos. Por outro lado, tratamentos químicos, como os processos alcalinos, tendem a aumentar o teor de cinzas devido à deposição de sais e compostos residuais resultantes da reação química (Madhu et al. 2020). ...
O uso de fibras de sisal como reforço em compósitos cimentícios vem sendo pesquisado, destacando-se pela sua disponibilidade na região norte de Minas Gerais. Neste contexto, o presente estudo teve como objetivo analisar as propriedades físicas e mecânicas de argamassas reforçadas com fibras de sisal. Para isso, foi empregado um tratamento físico baseado em ciclos de molhagem e secagem, conhecido como hornificação, visando melhorar a interação das fibras com a matriz cimentícia. Posteriormente, foram realizados os ensaios de absorção de água, teor de cinzas e umidade, a fim de verificar a eficácia do tratamento aplicado às fibras de sisal. Os resultados indicaram que o teor de cinzas, apresentou uma redução nos valores, passando de 1,93% para as fibras in natura para 1,11% nas fibras tratadas. Por outro lado, a hornificação provocou um aumento expressivo na capacidade de absorção de água das fibras, variando de 139,57% em 30 minutos para 251% em 2 horas, comportamento contrário ao esperado para tratamentos físicos que visam reduzir a higroscopicidade. A avaliação mecânica das argamassas demonstrou que, após o envelhecimento acelerado, a amostra de referência apresentou valores superiores de resistência à flexão (2,74 MPa), possivelmente em decorrência da continuidade das reações de hidratação. No entanto, as amostras contendo fibras de sisal apresentaram redução nos valores de resistência à compressão e à flexão, indicando que as fibras podem ter se degradado no interior do compósito ao longo do tempo. Sugere que, neste caso, o processo de hornificação pode ter comprometido a integridade estrutural das fibras, tornando-as mais porosas e susceptíveis à absorção de água.
... Paul et al. 23 have found that the permanganate treatment of Banana fibers increases their surface roughness, which results in better mechanical interlocking with the matrix and consequently increases the mechanical properties by 5% and 10% for polypropylene-treated Banana fiber composites. Madhu et al. 24 have concluded that the various chemical treatments of Americana agave fiber (hydroxide, stearic acid, benzoyl peroxide, and potassium permanganate) reveal a significant improvement in tensile test and elongation at break in all treated fibers. ...
... This is consistent with what the researchers found. 24,58 The increase in the density of the treated fibers could be due to the; (i) morphological changes of the fibers after treatment. The latter is conducive to the gradual elimination of microvoids present in the fibers, thereby reducing the volume and increasing the density 59 ; (ii) fiber cell walls are densified by removing impurities (less dense fats and waxes) 60 ; and (iii) pores are filled with the grafted molecules during the chemical treatment. ...
... This could be attributed to; (i) the removal of hemicellulose and lignin from the interfibrillar regions which leads to improving the cellulose chain packing along the direction of tensile deformation 74 ; and (ii) the increasing of cellulose content after the chemical treatment of fibers 75 ; and (iii) increased CI of the cellulose. Madhu et al. 24 have found that the treated Agave Americana fiber has a higher percentage of cellulose when compared to the untreated one. Many studies confirm the positive correlation between the amount of cellulose and the tensile strength of the fiber. ...
Bidirectional hybrid polymer-based composites are being introduced in many industrial applications. This is because the weaving patterns of woven composites have significant contributions to resulting composite performances. The main goal of this work was to study the effect of chemical treatments and the effect of hybridization on the mechanical properties of intra-layer hybrid Alfa/Jute fabric composites. Jute and Alfa fibers were used as natural fibers reinforcing the polyester matrix-based composites. First of all, the untreated, alkali and permanganate treated Alfa fibers were analyzed by using physical and mechanical tests (ATR-FTIR, XRD, and MEB). Weibull statistical analysis was employed to estimate the variability of untreated and treated Alfa fiber-resin interfacial shear strength. On the other hand, three plain-woven intra-ply hybrid fabrics were used as reinforcements for the polyester matrix. These three produced composite samples were subjected to mechanical, and physical tests such as three-point flexural strength, compressive strength, water absorption, and optical observation. The results were examined, analyzed, and compared to a jute-woven composite reinforced with the same resin. The results show that the chemical treatment can affect positively the fibers’ properties. In others hand, among the studied composites, the developed treated intra-ply woven fabric reinforced polyester resin have good mechanical properties in term of flexural and compression resistance. Weibull statistical analysis was conducted to evaluate and quantify the variability in the tensile strength of various intra-layer hybrid Alfa/Jute fabric composites.
... The nettle fibre was treated with 3 and 5 wt% alkali solution. The solutions at 3 and 5 wt% concentrations were prepared by adding 3 and 5 g of NaOH pellets in a solution of 100 ml volume, respectively [12,55]. The fibres were soaked for 1 h at room temperature, maintaining the fibre-liquor ratio of 1:20 (g/ml) [33,54]. ...
... The precalculated volume of silane was added to a water/mixture solution prepared with a concentration of 20:80% (v/v). The whole solution mixture was kept for 1 h at normal room temperature to complete the hydrolysis reaction of silane [12,55,56]. After completion of silane hydrolysis, the pre-defined weight of nettle fibre was soaked into the solution, maintaining the fibre weight to solution volume ratio at 1:20. ...
... The fibres were soaked in 3% and 5% (v/v) H 2 O 2 (hydrogen peroxide) solution at room temperature for 1 h separately [12,55,57]. H 2 O 2 is an excellent bleaching agent that helps break down of chromophoric groups such as ketone, aldehydes, and aromatic rings present in non-cellulosic and lignin contents of natural fibre. ...
Among different natural fibres, Himalayan nettle is gaining importance as reinforcement, an alternative to synthetic fibre, for polymer composite synthesis due to its wide availability, low price, and sustainable production. In this study, untreated (raw) and chemically treated nettle fibres were characterized by standard testing methods to find the best chemical type and concentration for surface modification, as there is not a single chemical treatment equally effective for all kinds of natural fibre. Alkali (3 and 5%), silane (1 and 3%), and hydrogen peroxide (3 and 5%) solutions were used for chemical treatment. The fibres were characterized by compositional analysis, XRD, FTIR, SEM, AFM, single fibre mechanical strength, and physical properties like diameter and fibre density. Among all chemical treatments, 3% alkali–treated fibre showed the maximum tensile strength (571.06 MPa), high cellulose content (83.8 wt%), high crystallinity index (82.55%), lower crystallite size (11.25 nm), highest roughness parameters (788 nm Rmax), lower fibre width, lowest microfibril angle, and higher elongation at break. The tensile strength of 571.06 MPa observed for 3% alkali–treated fibre was significantly high and suitable for reinforcement with polymer matrices. The 3% alkali–treated fibre exhibited the lowest weight loss (61.0%) in 2nd stage thermal degradation and the maximum residual weight (24.31%) at 800°C, indicating improved thermal stability than the other studied fibre samples. Thus, this study justifies the suitability of the 3% alkali treatment for surface modification of the nettle fibre to be utilized in polymer composite synthesis.
... Furthermore, the plants commonly grow along railway lines, roadsides, and riverbanks, generally in dry regions, especially in arid and semi-arid climates [12]. Due to its rich composition, Agave has a wide range of applications, such as in bioactive compounds [14,15], food ingredients [16,17], activated carbon [18,19], biofuel feeds [20], and biomaterials [21,22]. The yield per hectare of this plant is 300 tons per year. ...
... The spectrum of AF showed a broad band at 3320 cm −1 , corresponding to the O-H curvature, where the presence of α-cellulose is confirmed [22,44]. In addition, the peaks found around 2855 and 2928 cm −1 are associated with the elongation of CH 2 and CH 3 of the methyl and methylene groups, corresponding to lignin, cellulose, or hemicellulose [45]. ...
... From the curves in Fig. 6, the TGA curve of Agave fiber showed three stages of thermal degradation, the first occurred with an 18% weight loss at 30-200 °C which could be due to the eradication of moisture content and some waxy materials from the fibers [22]. It also presents a foremost degradation step between 225 and 350 °C, with 36.4% weight loss and a maximum reaction temperature equal to 300 °C, corresponding mainly to the decomposition of hemicellulose and α-cellulose [55]. ...
Globally, millions of tons of waste cooking oils (WCO) are generated yearly, and the recovery rate for manufacturing chemicals such as biodiesel is still low. Unfortunately, part of the WCO has been directly discharged into natural environments, underscoring the industrial significance of developing novel technologies for its utilization. As a possible solution to its recovery, this research proposes a new approach for Agave Americana fiber (AF) as a filler in castor oil-based polyurethane, obtaining ecosorbents and evaluating the sorption capacity of WCO. The pristine PU and PU/AFX% ecosorbents (X stands for AF content between 5 and 20 wt%.) were characterized by SEM, OM, density, FTIR, XRD, contact angle (CA), TGA, and water absorption. The inclusion of AF fillers impacted density and influenced morphological, physical–chemical, and thermal properties. Sorption capacity and efficiency were evaluated by varying the contact time and concentration in the oil/water system, and a direct influence of fiber content on sorption capacity was observed. PU/AF20% presented the highest CA and the best sorption capacity and efficiency. Response surface methodology (RSM) evaluated the optimization behavior of sorption capacity (for water and oil), emphasizing a strong dependency on sorption capacity as a function of fiber content variation. Langmuir and Freundlich isotherm models well defined the sorption mechanisms, and the Langmuir model demonstrated the best fit for PU/AF20%, exhibiting a maximum adsorption capacity of 163.93 g g-1. PU/AF20% reusability was evaluated for 21 cycles with a maximum efficiency of 74.2% for oil systems. Thus, AF is an innovative filler in castor oil-based polyurethane for discarded waste cooking oil sorption.
... Au fost selectate două condiții la două niveluri diferite, și anume timpul de impregnare (la 2 și 4 ore) și temperatura tratamentului alcalin (80°C și 120°C). Fibrele (14-22 tex), tenacitatea (6)(7)(8) și (13)(14)(15)(16)(17) cN/tex), alungirea de (2,3) și (3-6,2%), raportul de lignină de (20,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)7) și (15,13-22,6%), alfa-celuloză de (50,2-55,6) și (53-59%) și cristalinitatea de (43,9-58,6) și (55,4-66,3%). Rezultatele au arătat că fibrele de chenaf sunt foarte rezistente și mai subțiri decât fibrele de papură sau față de alte tipuri de fibre. ...
... This may be attributed to the excessive treatment conditions which can damage kenaf strength. NaOH begins to integrate into internal molecules of Kenaf fibres when it reaches a higher temperature and soaking time [21]. This difference in mechanical behaviour may also be explained later by the difference in chemical composition between Kenaf and Cattail fibres presented by high lignin levels for Cattail fibres. ...
NaOH treatment is widely used for natural fibre extraction. However, the different treatment conditions produce fibres with other characteristics. The present work aims to study the effect of alkali treatment conditions on Kenaf bast and Cattail stem fibres’ properties. Two conditions at two different levels were selected. They are soaking time (2 and 4 hours) and alkali treatment temperature (80 and 120°C). Untreated Kenaf and Cattail fibres were used as control samples. The NaOH process occurred due to the decline in the fineness of Cattail and Kenaf fibres. SEM micrographs of treated fibres showed a clear surface with rectangular pits for Cattail fibres and dissociation of the technical fibre. Best tensile strength obtained for Kenaf fibres for 80°C and under 4 hours. However, a temperature of 120°C and a duration of 4 hours confirmed the best results in terms of lignin removal, proved by IR spectra. Also, X-ray diffractograms suggested that the crystallinity index increases with the highest conditions. The properties of Kenaf bast fibres are found to be superior to Cattail fibres. Characteristic ranges of Cattail and Kenaf fibres after alkaline treatment can be resumed respectively as the diameter of (205–496) and (66–162 μm), the linear density of (31–48) and (14–22 tex), tenacity of (6–8) and (13–17 cN/tex), elongation of (2.6–3.3) and (3–6.2%), lignin ratio of (20.7–23.7) and (15.13–22.6%), alpha-cellulose of (50.2–55.6) and (53–59%), and crystallinity of (43.9–58.6) and (55.4–66.3%). Findings showed that Kenaf bast fibres are found to be great resistant and thinner than Cattail fibres and compared to other fibres.
... Agave americana fibers (AAFs) are a promising example of such natural fibers. Widely distributed and adaptable to harsh environments (Menachem, 2007), Agave americana offers a readily available source of cellulose-rich fibers (Hulle et al., 2015;Jani et al., 2020;Madhu et al., 2020) that can be extracted via mechanical or chemical processes (Thamae and Baillie, 2007;Mylsamy and Rajendran, 2010;Kolte and Daberao, 2012;Bezazi et al., 2014). However, the presence of water-soluble materials on the fiber surface hinders their compatibility with polymer matrices. ...
... However, the presence of water-soluble materials on the fiber surface hinders their compatibility with polymer matrices. To improve interfacial adhesion, chemical treatments with NaOH, stearic acid, benzoyl peroxide and potassium permanganate can be employed to modify the surface of Agave americana fibers (Thamae and Baillie, 2007;Ben Sghaier et al., 2012;Madhu et al., 2020;Thamarai Selvi et al., 2023). These treatments have significantly reduced the amorphous content of the fibers like hemicellulose and lignin, making them less resistant to water molecules and increasing their wettability. ...
Low-pressure N₂ afterglow treatment’s impact on Agave americana fibers’ (AAFs) surface andmechanical properties was investigated. AAFs were exposed to a N₂ microwave afterglow at100 W during 5 and 15 minutes. Treatment effects were evaluated through surface morphologyand mechanical properties. Scanning electron microscopy (SEM) revealed a roughened surfacedue to afterglow-induced etching. Mechanical tests demonstrated increased elastic modulus andtensile strength, attributed to surface cleaning and removal of amorphous deposits. X-raydiffraction and Fourier-transform infrared spectroscopy (FTIR) analyses supported these findings.This study suggests the potential of low pressure afterglows as a promising approach for AAFssurface activation and improved adhesion in polymer composites.
... To this end, the spines were cut from the edges and the fiber was removed by hand by cutting thin sheets approximately 20 cm long with knife and scissors [31]. The collected fibers were purified and functionalized with 5% (w/v) sodium hydroxide (NaOH) solutions, considering that 5% is optimal for most natural fibers [38], maintaining a temperature of approximately 40 °C for 4 h [23]. Subsequently, the treated natural fibers were washed several times using deionized water and an ultrasonic cleaning machine. ...
... The vibratory band at 2919 cm −1 is related to the stretching vibrations of CH and CH 2 in cellulose and hemicellulose [9]. Additionally, the presence of a strong band around 3324 cm −1 was attributed to the stretching of the O-H group with hydrogen bonds [38]. Figure 8 shows the infrared spectra of the FC-MNPs. ...
High mercury levels from industrial and natural sources necessitate effective water mercury removal methods owing to human and ecosystem toxicity risks. This study addresses the adsorption of Hg ions onto mixed-valent magnetite nanoparticles (MNPs) owing to their high surface area, reactivity, and magnetic recovery ability. The adsorption capacity of MNPs is influenced by the morphological characteristics. The influence of the vegetable fiber surface charge in magnetite, along with the change in pH, on the Hg ion adsorption process by MNPs remains an open question. The adsorption capacities of the synthesized MNPs and Cabuya fibers (Agave Americana L. ASPARAGACEAE) impregnated with magnetite nanoparticles (FC-MNPs) were compared. The synthesis and impregnation of MNps were performed using the chemical coprecipitation method with ferrous and ferric chloride as precursor solutions. The composition, surface properties, and morphology of the synthesized adsorbents were investigated by scanning electron microscopy (SEM) coupled with an energy dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and Raman spectroscopy (RS), which provided evidence that MNps reached an approximate diameter of 19 nm. Both adsorbents were used for the removal of Hg (II) at different initial pH values, times, temperatures, adsorbent dosages, and analyte concentrations. FC-MNPs and MNPs were able to achieve approximately 93% and 83% Hg (II) removal, respectively, under the following experimental conditions: the adsorbent dose 0.5 g, Hg (II) 10 mg/L, pH 5.0, stirring speed of 150 rpm, temperature of 25 °C, and equilibrium time of 4 h. Equilibrium data were evaluated by fitting the Langmuir and Freundlich isotherm models to the experimental conditions. Additionally, kinetic studies of pseudo-first and pseudo-second order were conducted to understand the mechanism of interaction between the adsorbent and the metal ions. The results show that FC-MNPs has a maximum adsorption capacity of Hg(II) of 4.95 mg/g of adsorbent, and that the reaction system follows pseudo-second order kinetics and the Freundlich isotherm model. Finally, the experimental results reported in this work show that cabuya fibers impregnated with MNPs have an important impact on the immobilization of aqueous contaminants. This offers a new method for developing novel nanocomposite adsorbents for the removal of metallic ions from wastewater.
... Table 2 depicts the outcome of the chemical analysis of CUFS fibre, and it is evident that the fibre has cellulose (73.51%), lignin (11.75%), and moisture content (6.77%) with a density of 1.102 g/cc. The cellulose content of CUFS fibre is higher than some of the natural fibres like Adscensionis fibres (70.8%) [30] and Agave americana (68.54%) [31] and lower than cotton linters (90%), Sansevieria ehrenbergii (80%), etc. [32]. The appreciable wt% of cellulose ensures better tensile properties in comparison with other natural fibres [31,33]. ...
... The cellulose content of CUFS fibre is higher than some of the natural fibres like Adscensionis fibres (70.8%) [30] and Agave americana (68.54%) [31] and lower than cotton linters (90%), Sansevieria ehrenbergii (80%), etc. [32]. The appreciable wt% of cellulose ensures better tensile properties in comparison with other natural fibres [31,33]. The ash content (0.37) and density of fibre (1102 kg/m 3 ) are found to be lower than many of the natural fibres which can improve the cohesive bond between the fibre and matrix [32]. ...
The work deals with the extraction and characterization of fibre from the unexplored Caryota urens fruit stem (CUFS). The spadix of Caryota urens (CU) has compound spadix inflorescence with a core and branching fruit stems covered by a boat-shaped spathe. The ripened fruit stems of the spadix after the removal of peripheral fruits and their residues are used for fibre extraction process. The fibre from the fruit stem is extracted by soaking it in portable water and then pounded. The mechanical and physical properties of the unexplored CUFS are quantified by tensile test, XRD analysis, SEM, FTIR spectroscopy, and TGA analysis to ascertain their ability to be a reinforcement for bio-composites. The maximum tensile strength and strain of 10 mm fibre are 11 N and 9.9%. The XRD analysis records a 63.39% crystallinity index and a 5.078 nm crystal size. The TGA recorded the thermal stability of fibre at 250 °C with a mass reduction rate of 5.35% per min. The SEM and FTIR report the favourable features of fibre towards adhesion and interfacial bonding with the matrix. Such quantified fibres are woven as unidirectional mats and treated by silane to four variants of epoxy laminates with and without Sisal hybridization. The laminate configurations F1 and F3 are 4 layers of CUFS mat without and with silane treatment, whereas F2 and F4 represent hybridization with Sisal (Sisal/CUFS/CUFS/Sisal) and silane treated, respectively. The silane treatment has significantly improved the storage modulus of the CUFS fibre composite up to 36.96% and the CUFS–Sisal hybrid composite to 128%. The tensile strength of the silane-treated laminate (F3) has increased by 12% over the untreated (F1) laminate attributed to the effect of fibre sizing. However, the combined effect of silane treatment and hybridization has witnessed a 67.7% rise in tensile strength (F4). These characteristics of CU fruit stem fibre ensure the profound calibre to be a potential reinforcement in bio-composite for lightweight structural applications.
... A fiber's surface roughness or smoothness can be determined by analyzing its outward appearance using SEM, which will provide insight into the fiber's bonding properties. 45,46 The material surfaces are analyzed using an electron microscope (SEM) fitted with a differential scanning system (EDS) to study its topography and morphology. To accomplish elemental detection, an EDS is used. ...
Natural fiber-reinforced composites could be obtained by utilizing agricultural wastes, fallen leaves, or abandoned materials as reinforcements after their usage as a way to reduce environmental impacts such as to stop deforestation, i.e., cutting down of plants and trees for their fibers, and in waste management, which includes recyling of natural wastes and minimizing the use of nonbiodegradable synthetic composites by replacing it with their natural fiber counterparts. As an outcome, leaves from a Terminalia catappa (Tc) tree grown in the Kanyakumari district that falls off in large quantities throughout the winter are gathered and examined. The leaves are treated with NaOH and KMnO4. In this investigation, all three powdered samples (raw, alkali treated, and permanganate treated Tc leaf fibers) are sent to chemical analysis, powder X-ray diffraction (p-XRD), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDAX), thermal analysis (TGA-DTA), and carbon hydrogen nitrogen sulfur (CHNS) analysis. The results of the research showed that the powdered Tc leaf samples had high levels of cellulose (≈ 50%), crystallinity index (≈ 50–65%), and crystallite size (≈ 3 nm). There are various vibrational bands associated with them. The rough surface of the raw and treated Tc powder samples and their particle size (≈ 50–100 μm), as revealed by the SEM images, might aid in good adherence with the matrix. According to EDAX and CHNS analyses, there is a high carbon content in all of the samples. The fibers have an activation energy (≈ 55–60 kJ/mol) and maximum temperature limit (≈ 500 °C) that are comparable to many other natural fibers. The density of Tc leaf fibers (≈ 0.2 g/cm³) is very low and so could be used in lightweight composite applications. The chemical treatments enhanced the qualities of Tc fibers to a certain extent. In various polymers, rubber, or concrete matrices where the inclusion of natural fiber reinforcement is desired, all three samples could function as potential reinforcements.
... Mechanical and physical properties of some natural fibers. Data summarized from references[13,[58][59][60][61][62][63][64][65][66][67]. © Sari et al.2025. ...
Composites made from biopolymers and natural fibers are gaining popularity as alternative sustainable structural materials. Biopolyesters including polylactic acid (PLA), polybutylene succinate (PBS), and polyhydroxyalka-noate (PHA), when mixed with natural fibers such as kenaf, hemp, and jute, provide an environmentally acceptable alternative to traditional fossil-based materials. This article examines current research on developments in the integration of biopolymers with natural fibers, with a focus on enhancing mechanical, thermal, and sustainability. Innovative approaches to surface treatment of natural fibers, such as biological and chemical treatments, have demonstrated enhanced adhesion with biopolymer matrices, increasing attributes such as tensile strength and rigidity. Furthermore, nano filling technologies such as nanocellulose and nanoparticles have improved the attributes of multifunctional composites, including heat conductivity and moisture resistance. According to performance analysis, biopolymer-natural fiber-based composites may compete with synthetic composites in construction applications, particularly in lightweight buildings and automobiles. However, significant issues such as degradation in humid settings and long-term endurance must be solved. To support a circular economy, solutions involve the development of moisture-resistant polymers and composite recycling technology. This article examines current advancements and identifies problems and opportunities to provide insight into the future direction of more inventive and sustainable biocomposites, and also the dangers they pose to green technology and industrial materials. These findings are significant in terms of the development of building materials which are not only competitive but also contribute to global sustainability.
... Natural fibers have several contents such as cellulose, hemi-cellulose, and lignin which have a structure as shown in Figure 3. One of the contents that affect the mechanical and physical properties of biocomposites is the cellulose content [39]. Cellulose is a long-chain polymer made up of carbon, hydrogen, and oxygen, with the chemical formula C6H10O5 [40]. ...
In the past decade, the development of biocomposite materials has attracted much attention due to the growing concerns about petroleum-based natural resource depletion and pollution. Among the various biocomposite materials, polylactic acid (PLA) is one of the most widely produced and ideal for use in commercial products. The manufacture of PLA biocomposites with natural fiber reinforcement as an alternative material that replaces synthetic materials is widely researched. The different types of natural fiber sources used in the incorporation of matrix and fibers are very important as they affect the mechanical properties of the biocomposites. In addition, PLA-based biocomposites can be produced by a wide variety of methods that can be found in various commercializations. This study aims to present the recent developments and studies carried out on the development of PLA-based natural fiber biocomposites over the past few years. This study discusses PLA biocomposite research related to their potential, mechanical properties, some manufacturing processes, applications, challenges, and prospects.
... This review investigates the reinforcement of natural fibers through chemical and surface treatment; it collects important sources from literature about retting methods used especially for characterization purposes. The work presented in another investigates (70) the feasibility of using Agave Americana C. fibers as a substitute for glass fiber reinforcements currently used within polymer composites. Subsequently, the chemical composition, structure, and properties of resulting fibers were determined for TAPPI analysis FT-IR spectroscopy thermal degradation tensile property measurement scanning electron microscopy (SEM) analyses. ...
The work studied the use of agro-industrial untreated waste for bio-composites as a sustainable material and determined its wettability in diverse environments. To prepare the bio-composites, Bhimal natural fiber was compositely reinforced with CaCO3 composite platelets and Flyash along with TiO2 at different concentrations (5%, 10%, and15% by weight) into an epoxy matrix. The samples were tested in petrol, diesel; kerosene, seawater Ganga water; rainwater, and distilled water at 168 hours and the saturation was stabilized after measuring every 48 h. The absorption resistance, especially in oil-based environments was excellent in TiO2 15%-based bio-composites. Materials were ranked by the Analytic Hierarchy Process (AHP) and TOPSIS methods. The results show the potential of TiO2 composites for low wettability applications without any chemicals as well, which may encourage green materials from agro-industrial waste.
... Chemical treatment can enhance the interface adhesion and reduce the amount of water absorption [6]. The results of the chemical analysis show that the fibers' resistance to water molecules can be decreased and their amorphous contents, such as hemicellulose and lignin, can be significantly reduced by applying various chemical treatments [7]. Hemp fiber reinforced epoxy composites' tensile and flexural properties are improved by trimethoxysilane treatment, however no high values are attained. ...
This study investigates the enhancement of natural fiber composites by exploring the effects of various chemical treatments on JUCO fiber and banana fiber composites. The common drawbacks of these composites, particularly their high water absorption and poor dimensional stability, are examined by conducting five different chemical treatments. The research evaluates how these treatments influence the hydrophilic properties of the fiber-reinforced composites (FRC). The study further explores the water absorption behavior and the kinetics of the diffusion mechanisms, with the goal of minimizing the moisture uptake and improving the dimensional stability of the composites. The mechanical properties, specifically tensile and flexural strengths, are also assessed in both the samples soaked in a pH 7 medium and in dry condition. Additionally, the study uses ABAQUS to validate the tensile and flexural strength of the treated composites, providing a deeper understanding of their mechanical performance. By combining experimental and simulation-based approaches, the research aims to offer insights into how chemical treatments can optimize the performance of natural fiber composites for various engineering applications.
... Removal of lignin and hemicellulose is shown to effectively smooth the fiber surface, thereby rendering it cleaner and more crystalline. The SEM images of the resulting fiber morphology provide evidence for enhanced texture at the surface, which promotes better matrix-polymer integration within composite applications [21]. ...
This investigation discusses the extraction and characterization of banana fiber from pseudostems of the Nendran and Grand Naine banana variety, with a special focus on the latter’s potential to act as a sustainable reinforcement in green composites. The Nendran pseudostem fiber exhibited fine linear density with 14.50 tex, excellent breaking load with a value of 327.33 g, and tenacity of 22.92 g/tex. The result of chemical analysis of Nendran fibers is an amount of 59.22% cellulose, and it can also be used in high-performance applications. It shows the existence of cellulose, hemicellulose, and lignin due to the crystallinity index being 20.33%, which proves improved mechanical properties. A maximum degradation temperature at 370.94 °C has verified its thermal stability, which can also aptly suit applications that require heat resistance. This study’s philosophy is to encourage the utilization of banana fiber as a biodegradable reinforcement for replacing synthetic reinforcements of industries such as automotive, aerospace, and textiles.
... In the casting method, short, discontinuous fibers are dispersed in the matrix, allowing better control over fiber orientation and distribution, which can optimize mechanical performance based on the application. In hand lay-up, as seen with kenaf fiber composites with varying weight percentages (10-20 g), the mechanical properties improved by 15% due to strong bonding between epoxy and the fibers [2]. However, the casting method offers greater potential for achieving uniform fiber dispersion, particularly in hybrid composites, which can enhance stress transfer at the fiber-matrix interface more efficiently in certain cases. ...
The transition to sustainable materials in composite manufacturing is crucial for reducing environmental impact and costs. Natural fibers, particularly from plants like Hibiscus Rosa-Sinensis, offer an eco-friendly and cost-effective alternative to traditional reinforcement materials in polymer composites. This study explores the development and characterization of polymer composites reinforced with chemically treated Hibiscus Rosa-Sinensis (HRS) fibers. HRS fibers, derived from the plant Hibiscus Rosa-Sinensis, are notable for their availability, mechanical properties, and environmental benefits. The research investigates how fiber weight percentage, fiber length, and fiber thickness affect the physical and mechanical properties of the composites, including void content, microhardness, water absorption, tensile strength, flexural strength, and Impact Strength. Composites with a fiber configuration of 15 Wt%, 10 mm length, and 2 mm thickness have exhibited optimal performance, achieving an ultimate tensile strength of 30.76 MPa, flexural strength of 50.8 MPa, Impact Strength of 119 J m⁻¹, and a peak microhardness of 22.326 Hv. These parameters significantly enhance the composite’s structural integrity and durability. The study also highlights the critical role of fiber dimensions i.e. with greater fiber weight percentages leading to increased void content and water absorption rates, which peaked at 6.19% and 3.45%, respectively. Further, predictive modelling using Feed-Forward Artificial Neural Network (FFANN) and Response Surface Methodology (RSM) revealed that FFANN has outperformed RSM, achieving an average accuracy of 95%–98% compared to the average accuracy of RSM at 85%–90%. Finally, microstructural analysis has corroborated with the experimental results, highlighting the potential of Hibiscus Rosa-Sinensis fibers in enhancing the performance of natural fiber-reinforced composites for various industrial applications.
... PMCs offer design versatility as a result of their ability to be molded into intricate shapes and geometries. Engineers can optimize designs for both functional and aesthetic purposes due to this adaptability (Madhu et al., 2020). Numerous polymer matrices utilized in PMCs have inherent corrosion resistance, reducing the need for additional protective coatings. ...
In today's materials engineering, composite materials are essential since they combine different components to provide better performance characteristics. These materials are made up of the reinforcement itself, which improves mechanical qualities like strength and stiffness, and a matrix that binds and shields the reinforcement. The customisable features of polymer matrix composites (PMCs), in which fibers or particles serve as reinforcement and a polymer resin typically serves as the matrix, are noteworthy. Because of their lightweight, adaptable, and durable architecture, composites are utilized extensively in the building, automobile, aircraft, and sports industries. A high strength-to-weight ratio, resistance to corrosion, and the capacity to be shaped into intricate designs are some of its main benefits. Together with its outstanding fatigue resistance, affordability, and environmental advantages, composites also support cutting-edge engineering and production techniques and environmentally friendly products.
... Shows the effect of chemical treatment on the physical and mechanical properties of bamboo fibers as potential reinforcement for polymer composites (Kudva, Gt, and Pai 2024). Madhu et al. (Madhu et al. 2020) investigated the effect of various chemical treatments, including NaOH, stearic acid, benzoyl peroxide and potassium permanganate on Agave Americana fiber for composite reinforcement. They reported that chemical analysis shows that various chemical treatments significantly reduce amorphous contents such as hemicellulose, lignin, and other impurities, making the fibers less resistant to water. ...
This review presents a comprehensive overview of recent trends, advances, and challenges in the use of natural fiber composites. This section begins by discussing the growing adoption of bio-based fibers because of their eco-friendly nature and cost-efficiency, focusing particularly on plant-based fibers. A bibliometric analysis will be conducted to evaluate the publication frequency and research trends in this domain. Furthermore, the structural compositions of natural fibers, including cellulose, hemicellulose, lignin, pectin, and wax, were elucidated, highlighting their significance in composite material engineering. The extraction methods of natural fibers, including retting and mechanical decortication, are discussed, along with their implications for fiber quality. The limitations associated with natural fibers, including their hydrophilicity and poor mechanical properties, compared with their synthetic counterparts are addressed. Various surface-treatment methods, particularly physical and chemical ones, were explored to enhance fiber compatibility with polymer matrices. The abstract delves into the principles, techniques, and effects of physical and chemical treatments on natural fibers, emphasizing their role in improving the surface characteristics, interfacial adhesion, and overall mechanical properties of composites. Furthermore, specific studies investigating the impact of physical and chemical treatments on natural fibers are summarized, elucidating the observed changes in fiber morphology, chemical composition, and mechanical properties.
... The maximum stress that the material can withstand when subjected to tensile (pulling) forces before it undergoes failure was 41% more for sample E when compared with sample A. In previous work, a sisal fiber-reinforced alumina particulate epoxy composite revealed a tensile strength of 64.29 MPa which is a 56% superior stretching strength compared to the present Cucumis sativus fiber composite, the major reason behind this value being addition of metal oxide filler that can improve the load-carrying capacity when compared to sawdust filler particulates. 31 The incorporation of Cucumis sativus fibers and sawdust fillers into the epoxy matrix contributed to the composite's ability to resist stretching and deformation under tension. The Cucumis sativus fibers, with their inherent strength and stiffness, reinforce the composite and enhance its load-bearing capacity. ...
This research investigates the impact of sawdust fillers on Cucumis sativus fiber‐reinforced polymer composites through a conventional hand layup process. The objective is to develop a novel material suitable for static applications that is both lightweight and environmentally sustainable. A range of analytical techniques including X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, mechanical testing, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy‐dispersive X‐ray (EDX) analysis were employed to thoroughly characterize the resulting composite material. By integrating Cucumis sativus fibers and sawdust fillers into a polymer matrix, the study demonstrates the potential to create materials with improved mechanical properties due to addition of sawdust filler, including tensile strength (27.61 MPa), flexural strength (32.84 MPa), impact resistance (14.7 J cm⁻²) and hardness (42). These enhancements, averaging at 16.2%, are attributed to the addition of sawdust filler, which opens new avenues for environmentally conscious engineering solutions. XRD analysis reveals the composite's crystalline structure, indicating a crystallinity index of 64.5% and the orientation of crystalline planes. FTIR spectroscopy identifies chemical bonding and CO and CO functional groups present in the material with major peaks at 2123 and 2438 cm⁻¹. TGA assesses the composite's thermal stability and decomposition behavior up to 380 °C. Additionally, SEM imaging elucidates the microstructural features and distribution of Cucumis sativus fibers and sawdust fillers within the epoxy matrix, while EDX analysis provides quantitative data on elemental composition. © 2024 Society of Chemical Industry.
... Spent or degraded substrate is the residue left after fungal production, which presents changes in its composition derived from fungal degradation and its increasing accumulation has prompted governments and researchers to address the potential use of this material Rinker (2017) such as pectins, lignin, and hemicellulose giving rise to the fiber structure Bessadok et al. (2009). In addition to these substances, the fiber surface is also covered by waxes due to fatty acids present in the plant Madhu et al. (2020). De Jesús-Rivera et al. (2009) point out that Pleurotus species can simultaneously degrade cellulose, hemicellulose and lignin, with lignin being the first to degrade completely, leading to the formation of inter-fibrillar spaces, leaving the cellulose clean. ...
The bagasse of Agave salmiana (maguey pulquero) is a residue generated during the exploitation of the plant to obtain pulque, inulin, honey, etc. Due to its chemical composition, it can be used for the cultivation of fungi of the Pleurotus genus and the subsequent use of the degraded material "degraded substrate (DS)" as a support for the germination of vegetables. The objective of the study was to characterize the bagasse of maguey pulquero biodegraded by Pleurotus djamor as a new perspective in its value chain, and subsequent use for the germination of Lycopersicon esculetum (tomato). The DS was recovered at 60 d from the P. djamor culture, characterized physicochemically and the conformation of the plant tissue was observed by scanning electron microscopy. The DS showed a decrease in protein (4.8–3.3 %) content and fibrous fraction (54–36 %), but dry matter digestibility increased from 47 to 71 %; in addition, changes in mineral composition were observed, mainly in calcium concentration (6 %). Due to its composition, it is possible to revalue DS in the germination of L. esculetum to reduce the use of peat moss (commercial peat). The results show that up to 25 % of maguey DS mixed with 75 % peat moss can be used (25:75), reaching a germination percentage of 85 % and increasing the seedling emergence speed index from 0.96 – 1.25. Concluding that it is possible to implement a circular strategy in which agave bagasse is used for mushroom cultivation and the subsequent recovery of the spent substrate for tomato germination.
... Afterward, the fabrics were rinsed with distilled water to eliminate any residual impurities from the tap water and then placed in a hot-air oven at 55-60 1C for one hour. 17 To further purify the fibers, they were immersed in a 2% NaOH solution for two hours in normal room temperature conditions (30 AE 2 1C), effectively removing the pectin and waxes from the peripheral region. After this treatment, the fibers were rinsed with diluted acetic acid (0.01 M), followed by de-ionized water to neutralize the alkaline effect. ...
Natural fiber-reinforced biocomposites offer sustainable alternatives to conventional plastics. This study investigates the development of biocomposites using coconut spathe fiber, a renewable byproduct, reinforced with corn starch and poly(vinyl alcohol)....
... After the silane treatment on the woven areca fiber and bronze nanoparticle, the composite material is fabricated by under hand layup technique [29]. First, the prepared mold surface is wax coated, in order to obtain smooth finishing surface of the composite plate. ...
Global warming and climate change condition are prevailing due to over exploitations of natural resources like fossil fuels, heavy metals, and dumping of wastages in open space. To bring solution to these less dense composite materials using waste biomass is now researched widely by scientists under various applications. The mechanical, tribological, wear, water absorption, and thermal conductivity properties of composite materials reinforced with bronze nanoparticles and areca fiber coated with vinyl silane are investigated in this research work. The novelty of this research study is to investigate how the composite’s characteristics were affected by the vinyl silane–treated bronze nanoparticle. Using a hand layup technique, the fabrication was cured for 24 h at ambient temperature and then post-cured at 120 °C. The AB2 (Areca fiber of 40 vol.%, Bronze nanoparticle of 3 vol.%) composite demonstrated stronger mechanical properties, including a tensile strength of 37.2%, a flexural strength of 22.4%, and an izod impact strength of 36.6% when compared to fiber- and matrix-reinforced base composite AB0 (areca fiber 40 vol.%, resin 60 vol.%, bronze nanoparticle 0 vol.%). In contrast, the AB3 composite displayed remarkable hardness at 84 Shore-D, outstanding wear resistance at 0.011 mm³/Nm, superior thermal conductivity at 0.212 W/mK, and excellent hydrophobicity at 0.12%. Further, when compared to the thermal conductivity of AB3 composite shows 34.2% higher than the thermal conductivity of base composite AB0. Similar such increase in values is attained in other composites compared to AB0 composite. Furthermore, vinyl silane–treated bronze nanoparticles are present in greater volume fractions in AB2 and AB3, which increase reinforcement inside the composite matrix and improve mechanical characteristics. The SEM (scanning electron microscopy) results corroborate that the vinyl silane treatment improved the bond strength of the fiber, filler, and resin. The reinforcement of vinyl silane–treated metallic nanoparticle and natural fiber reinforcement shows better mechanical, wear resistance, and thermal stability property which could be utilized in areas such as automotive, aerospace, defense, and structural applications.
... The chemical analysis results indicate that the application of different chemical treatments on the fibers can bring significant reduction in the amorphous contents like hemicellulose, lignin, and other impurities and make them less resistant to water molecules. Almost similar tensile strength with hydrophobicity [48]. ...
As natural fibers in composites improve performance and reduce non-renewable resource use, the present study develops a vinyl ester composite reinforced with Sesbania grandiflora stem fibers which is available in nature. For the first time, the stem fiber of Sesbania grandiflora was reinforced with vinyl ester matrix via compression molding to yield a novel composite material with the detailed characterization of mechanical, physical, thermal, chemical, and fiber-matrix bonding properties. Composites are fabricated using fiber loadings ranging from 0 to 35 wt.%. The composites with 35 wt.% fiber loading had 204.2%, 101.35%, and 287.22% higher tensile, flexural, and impact strengths than those without fiber loading. The composite with 15 wt.% fibers increased hardness the most by 4.56% compared to the bare matrix material. The chemical distribution and thermal stability were analyzed using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). TGA was employed to assess the thermal stability of the composite. The material’s eco-friendliness was demonstrated by biodegradability testing. The examination of the fracture surfaces under tension provides insights into the bonding properties between the fiber and matrix at the interface. The studies illustrate the capacity of sustainable composites in the fields of aerospace, automobile, and building.
Development of natural fiber reinforced polymer composites over synthetic based composites offers numerous benefits such as biodegradability, sustainability, light weight, higher strength to weight ratio and yet cost effectiveness. Most of the components like bearings, pulleys, gears, bushes, pulley linings, brake pads, friction plates etc., are mainly made of composite materials which requires understanding of their tribological behavior. Thus, for the first time, study is undertaken to investigate the two-body abrasion wear behavior of the Alstonia macrophylla fiber reinforced Polypropylene (A-PP) composites using pin on disk machine for the selected input variables which is in accordance with ASTM G 99 standards. A-PP composites consisting 40% of fiber volume are prepared by adopting film stacking method and cured under compression molding machine. Sliding distance, grit size of abrasive paper, and applied load are selected as an input variable and their output responses measured are coefficient of friction (COF) and specific wear rate (SWR). Experimental results revealed that, both COF and SWR are found to decrease with increase in the applied load. Moreover, finer abrasive paper (1000 grit size) found to be less effective against the A-PP specimen compared to coarse abrasive paper (320 grit size). Formation of thin polymer film and accumulation of wear debris between the grits during the increase of load are found to be more appealing reasons for decreasing COF and SWR. Same observations are exposed by the FESEM analysis. Furthermore, feedforward backpropagation artificial neural network (ANN) is implemented to predict the aforesaid output responses. Confirmatory results showed that experimental and predicted values are within the acceptable range. For COF, error in prediction within ±6%, whereas for SWR it is ±7%.
The growing global demand for sustainable and environmentally friendly polymer materials is driving interest in cellulose‐based materials. In response to this need, lignocellulosic fillers (LF) were extracted from pruning waste of bing cherry tree (Prunus Avium L.) branches as an alternative source of filler materials. The extracted LF were characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Their chemical composition, density and particle size distribution (PSD) were also analyzed. In the second part of the study, biocomposites were prepared by incorporating fillers with particle sizes below 100 microns into an epoxy matrix at concentrations of 5%, 10% and 15% by weight. These biocomposites were then characterized by tensile test, three‐point bending test and SEM analyze to determine their mechanical and morphological properties. Among the biocomposites, the one with 5% wood filler showed the best properties with a tensile strength of 45 MPa, tensile modulus of 1883 MPa, flexural strength of 74 MPa and flexural modulus of 2559 MPa. The results demonstrate the effectiveness of lignocellulosic particles in improving polymer matrices and suggest their potential for use in non‐structural applications in the automotive and marine industries, such as interior panels.
Highlights
Cherry tree pruning waste has been characterized for the first time.
The potential use of cherry tree pruning waste as a filler material in thermosets has been investigated for the first time.
This study aims to contribute to the reduction of plastic consumption and the development of environmentally friendly products.
Liquid smoke (LS), an eco-friendly substance, is effective in modifying natural fibers to enhance their mechanical properties, surface morphology, and thermal stability. This study investigates the effects of LS immersion followed by microwave treatment on the tensile strength, surface morphology, and thermal characteristics of Sansevieria trifasciata Laurentii (STL) fibers. Response surface methodology (RSM) with central composite design (CCD) was used to optimize treatment parameters, including LS immersion time, microwave heating temperature, and duration. Mechanical, morphological, structural, and thermal properties were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Optimal treatment conditions: 120 min LS immersion and microwave heating at 40 °C for 30 min. They resulted in a tensile strength of 370.23 MPa, a 37.21% improvement compared to untreated fibers. Treated fibers exhibited enhanced thermal stability, increased crystallinity, and improved surface morphology. These findings demonstrate that LS and microwave treatments effectively enhance STL fibers’ mechanical properties, surface morphology, and thermal stability, positioning them as promising reinforcement materials for sustainable composite applications.
In this article, the mechanical properties of carbon fiber reinforced polypropylene (CF/PP) composites at different carbon fiber (CF) mass fractions were systematically investigated. A comprehensive examination is provided through the integration of experimental testing, numerical simulation, and theoretical analysis, revealing the enhancement effects of CF on the polypropylene (PP) matrix across multiple scales. Experimental results demonstrated that the incorporation of CF significantly impedes crack propagation and enhances the fracture resistance of the composites. Specifically, at a CF mass fraction of 15%, the elastic modulus of the composites is enhanced by 21.7% compared with pure PP, while the tensile strength increases by 40.9%–43.2%. The addition of maleic anhydride grafted polypropylene (MAH‐g‐PP) as a compatibilizer significantly improves the interfacial compatibility between CF/PP. Furthermore, finite element simulations revealed the damage evolution process at the CF/PP interface during tensile loading. Based on the Mori‐Tanaka model, the elastic modulus was predicted, aligning well with experimental and simulated results. This research offers a scientific basis for the design and application of CF/PP composites and contributes to the advancement of high‐performance composites.
Highlights
CF/PP composites show enhancements in mechanical properties with CF addition
MAH improves interfacial adhesion between CF and PP, boosting tensile strength
Multiscale experimental and FEA studies reveal CF/PP interface damage mechanisms
Mori‐Tanaka model accurately predicts the elastic modulus of CF/PP composites
With increased concern about reducing the carbon footprint on the earth and promoting sustainability, research on economic bio-products has gained significant attention in recent years. Natural fibers and their derivatives, such as composite materials have gained considerable interest due to their low cost, sustainability, biodegradability, mostly acceptable mechanical properties, and availability. It is vital to recognize the interactive characteristics of cellulosic natural fibers with matrix materials to effectively utilize such fibers as the reinforcement phase in forming composite materials. However, the characterization of these fibers and their composites is complex due to their natural origin and lack of homogeneity. An effort is made here to provide an overview of the current state of knowledge on the characterization, and the methods for characterizing the morphology, composition, thermal and mechanical properties of natural fibers and their composites. The review of characterizations involves Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray Diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Tensile, Flexural and impact behaviour of the composites. This review presents a comprehensive understanding of the key characteristics of cellulosic fibers and their composites, serving as a valuable resource for researchers, engineers, and practitioners involved in developing and utilizing eco-friendly materials.
The use of environmentally friendly materials for industrial applications has increased tremendously in the past decades due to environmental concerns associated with using synthetic materials. The present comparative investigation studied the properties of raw and chemically-treated coconut shell biomass for possible polymeric composite applications. The coconut shell biomass was treated with alkali (NaOH), bleaching and combined NaOH-bleaching solutions and investigated the surface morphology, chemical transformations, and thermal stability. Untreated and chemically modified coconut shell biomass was characterized through the determination of chemical constituents, X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), thermogravimetric (TGA), and morphological analyses.
Chemically treated coconut shell biomass reported a significant increase in cellulose constituents, reaching 74.72% for combined NaOH-bleach treated samples with accompanying reductions in lignin and hemicellulose, as confirmed by FTIR spectroscopy. Further, the study reported an increase in crystallinity index with chemical treatment. For instance, combined NaOH-bleach treatment reported a maximum crystallinity index of 80.29% compared to 44.82% for untreated biomass. Alkali treatment improved thermal stability as indicated by an increase in the onset temperature of degradation to 255°C from 250°C for raw samples. Post-treatment, improved surface purity and roughness were observed, indicating enhanced fibre/matrix interlocking during composite fabrication. Moreover, combined NaOH-bleaching treatment exhibited enhanced surface hydrophobicity, as indicated by a maximum C/O ratio of 0.93 compared to 0.64 for untreated samples. In conclusion, combined NaOH-bleaching treatment significantly improved the chemical, structural and morphological properties of coconut shell biomass, suggesting its potential for developing low-cost, lightweight, renewable, and sustainable composite materials.
Liquid smoke (LS), known for its environmentally friendly properties and its ability to modify natural fibers, has been used to enhance the tensile strength of Sansevieria trifasciata Laurentii (STL) fibers through soaking in LS and microwave heating treatment. In this study, the Full Factorial Design (FFD) approach was employed to determine the optimal combination of treatment factors to achieve maximum tensile strength. The predicted optimal treatment combination was obtained through soaking in LS for 166 min, followed by microwave heating at 42 °C for 25 min, with a predicted tensile strength of 350.38 MPa. Confirmation tests through experiments under optimal conditions showed an average tensile strength of 353.43 MPa, representing an increase of 30.99% compared to untreated fibers, which had a tensile strength of 269.82 MPa. SEM analysis revealed significant changes in the fiber surface morphology, while FTIR spectra showed a reduction in lignin and hemicellulose content, indicating increased fiber reactivity. Furthermore, XRD analysis confirmed an increase in crystallinity index by 21.47%, which correlated with improvements in mechanical properties and surface morphology, including enhanced roughness that facilitates better adhesion for composite applications. These findings provide valuable insights for the development of environmentally friendly composites with superior tensile strength and optimized fiber properties.
Increase in usage plastic substance has dominated the effects of global warming by directly burn and dump those PET (Polyethylene terephthalate) like plastic substance in the open atmosphere. This study investigates the mechanical, thermal, and flammability properties of vinyl ester composites reinforced with 30 vol% Areca fruit fiber, cellulose, and a recycled PET bottle waste foam core, with a focus on the effects of silane coupling agents on these properties. The recycled PET bottle waste foam and Areca fruit fiber were surface-modified using a 3-Aminopropyltrimethoxysilane (APTMS) coupling agent to enhance interfacial bonding and improve the composites’ resistance to thermal and water-induced degradation. Post-fabrication, the composites underwent aging under various conditions, including exposure to borewell water, reverse osmosis water (RO), and elevated temperatures of 40 °C and 50 °C for200 hrs. The results demonstrated that silane-treated composites with 30 vol% Areca fibers provided significantly better shear, thermal conductivity, and flammability, drilling properties than their untreated counterparts, even after extensive aging. Silane-treated composites, including B2, C2, D2, and E2, showed significant improvements in mechanical, thermal, and flammability properties under various aging conditions. For composite B2, aged in borewell water for 200 h, rail shear strength increased from 17.18 MPa to 19.2 MPa, lap shear strength from 17.33 MPa to 20.3 MPa, and thermal conductivity from 0.14 W/mK to 0.17 W/mK. Moreover, composite D2, aged at 40 °C, showed improvements in rail shear strength from 16.34 MPa to 18.3 MPa, lap shear strength from 16.2 MPa to 19.2 MPa, and thermal conductivity from 0.12 W/mK to 0.15 W/mK. Furthermore, the SEM analysis of silane-treated vinyl ester composites reveals that the application of silane coupling agents and the inclusion of cellulose significantly enhance interfacial bonding and microstructural integrity. Drilling tests on silane-treated composites with 60 vol% PET foam core, 30 vol% areca fiber, and 3 vol% cellulose filler using 4 mm and 8 mm top drill diameters show reduced kerf widths compared to untreated composites. These findings confirm that the application of silane coupling agents significantly enhances the thermal stability, water resistance, and overall durability of the composites, making them suitable for demanding applications requiring high mechanical strength, effective thermal management, and robust fire resistance, particularly under challenging environmental conditions.
This review examined the current developments in wire mesh reinforced natural fiber composites (WMRCs), emphasizing their material properties, applications, and production techniques. WMRCs provide a sustainable and economical alternative to conventional synthetic composites. Natural fibers (NF), including flax, jute, and hemp, offer superior mechanical characteristics and diminish environmental effects. The incorporation of wire mesh improves the structural integrity of the composite. WMRCs provide exceptional durability and wear resistance, rendering them appropriate for use in the automotive, aerospace, and construction sectors. They provide enhanced mechanical qualities relative to single-fiber reinforced composites. The attributes of the wire mesh, including type, orientation, and material, substantially affect the performance of the composite. This research examines optimum drilling settings for WMRCs utilizing techniques such as Abrasive Water Jet Machining (AWJM). The primary fabrication techniques for WMRCs consist of hand layup and vacuum bag molding, with possibilities for compression molding and pultrusion. In conclusion, WMRCs offer a potential pathway for the advancement of composite materials. Subsequent study ought to concentrate on enhancing wire mesh reinforcement for particular applications, tackling water absorption challenges, and investigating novel wire mesh materials and manufacturing techniques.
This study investigates the potentiality of Gladiolus hybrida leaf fibers (GHLFs) as an eco-friendly reinforcing substance for polymer-based composites. Novel natural fibers were harvested from Gladiolus hybrida leaves (GHL) and treated with NaOH alkali (T-GHLF) to assess their influence on physical, strength, molecular, and heat-related properties. Initially, the obtained fibers had a diameter of 0.3084 mm, which reduced to 0.2524 mm following alkali treatment. Chemical investigation indicated that the cellulose content increased to 57.16 wt %, an enhancement of 11.38% over the untreated fibers, which had a cellulose content of 51.32 wt %. The degree of crystallinity percentage of the raw and processed fibers was 57.85% and 60.82%, respectively, without significant change in the cellulose phase. The thermogravimetric analysis indicated that T-GHLF exhibited improved thermal stability up to 257.77°C, with the kinetic activation energy (Ea) measured at 81.56 kJ/mol. Fourier transform infrared spectroscopy (FTIR) has been employed to observe the distribution of different chemical groups on the fiber surface. Scanning electron microscopy (SEM) revealed that the fibers had a roughened surface. According to tensile testing of a single fiber, the Young's modulus values for GHLFs and T-GHLFs were 2.08 and 2.21 GPa, respectively. These evidences suggested that GHLFs exhibited characteristics comparable to those of presently used natural fibers, positioning them as a strong contender to replace organic fibers in resin matrix composites. As a result, these novel natural resources may assist in achieving the Sustainable Development Goals of the United Nations through the sustainable utilization of agricultural waste in polymer matrix composites.
The integration of natural fibers into Fiber Reinforced Polymers (FRPs) has emerged as a promising avenue for sustainable and high-performance composite materials. Natural fibers, derived from plants, offer notable advantages such as renewability, low cost, and environmental friendliness. Among these natural fibers, Hibiscus Rosa-Sinensis (HRS) plant fibers have gained significant attention owing to their widespread availability and unique mechanical properties. In this study, HRS fibers were chemically treated using Sodium Hydroxide (NaOH), Potassium Permanganate (KMnO4), and Acetic Acid (CH3COOH) at different weight percentages (3, 4, 5 Wt.%) and solutionizing times (1, 2, 3 h) based on Taguchi’s L27 orthogonal array. The fibers, extracted from epidermis of the stems, underwent cleaning and chemical treatment after water retting. The crystallinity index, determined via X-ray Diffraction (XRD), indicated a maximum value of 65.77%. Thermo-gravimetric analysis (TGA) exhibited a degradation temperature of 365.24 °C and a material loss of 63.11%. Potassium Permanganate treatment at 4 Wt.% and 3 h of solutionizing time has yielded the best results. Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) has been successfully applied to accurately predict the output physical characteristics of chemically treated HRS fibers using experimental data. The results are in close alignment with the literature. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) analyses have provided valuable insights into the microstructure and constituents of the chemically treated HRS fibers. This research emphasises on the effectiveness of the chemical treatment process in enhancing the properties of HRS plant fibers for potential composite applications.
This study investigates the performance of vinyl ester composites reinforced with areca fruit fiber, microcrystalline cellulose, and silane coupling-grafted recycled PET bottle waste foam under conditions of water and heat-accelerated aging. The reinforcement, areca fiber and recycled PET foam were surface-modified using 3-aminopropyltrimethoxysilane (3-APTMS) to enhance interfacial bonding. The composites were fabricated using a manual hand layup process and subjected to aging tests. According to results the APS2 composite had enhanced heat conductivity at 0.17[Formula: see text]W/mk and decreased flame propagation speed at 10.99[Formula: see text]mm/min after being exposed to saltwater. Similarly, after being exposed to rainwater, the ARP2 composite developed a temperature conductivity of 0.16[Formula: see text]W/mk, a flexural strength of 80.3[Formula: see text]MPa, a tensile strength of 37.4[Formula: see text]MPa, and a flame propagation speed of 10.97[Formula: see text]mm/min. SEM analysis of silane-treated vinyl ester composites reinforced with areca fibers and microcrystalline cellulose reveals improved interfacial bonding and filler dispersion, enhancing the composite’s mechanical integrity. These findings confirm that the application of silane coupling agents significantly enhances the thermal stability, water resistance, and overall durability of the composites, making them suitable for demanding applications requiring high mechanical strength, effective thermal management, and robust fire resistance, particularly under challenging environmental conditions.
The surging demand for energy-efficient products and their environmental implications are important propelling factors contributing to the growing popularity of natural fiber-reinforced polymer composites (NFRPCs) in several domains. NFRP composites diversification significantly influenced the study and their development in recent years. The intrinsic characteristics of natural fibers have posed difficulties in the growth and use of NFRPCs. A significant amount of study has recently been performed to solve these sorts of problems in order to enhance the performance of NFRPCs and their uses. This review article aims to provide a comprehensive overview of the chemical composition of natural fibers, their physical and mechanical characteristics, and factors affecting the flexural and impact strength of NFRPCs, such as type of fiber, weight percentage of fiber, fiber geometry, surface treatments, stacking, hybridization, orientation, fillers, and information accomplished with them. The product life-cycle evaluation and sustainability development of plant-based NFRCs and the growing uses of NFRPCs, focusing on the automobile sector, are also explored. Finally, multiple perceptions were concluded with the expectation that this study may contribute to future improvements in the flexural and impact strength of NFRPCs.
This research aims to extract fibers from Washingtonia robusta petiole waste (WRP) and characterize them to investigate their potential. WRP fibers were treated for 2 h using different concentrations of NaOH solution (1, 3, 5, and 10% by weight) and then soaked for 2 h. The treatments adopted have shown improvements in certain chemical, physical, morphological, thermal, and mechanical properties. This study revealed that the crystallinity index was improved by 40 to 50%. FTIR analysis confirmed the reduction and degradation of hemicellulose for the optimally alkalized fiber. The SEM micrograph results of alkali-treated fibers showed rougher surfaces. The higher thermal stability was achieved when the alkali treatment with 5% NaOH was adopted. Further, fibers treated with 5% NaOH demonstrated interesting tensile properties, clearly superior to those found in the literature: tensile strength, Young’s modulus, and strain to failure of 678 ± 35.24 MPa, 11.2 ± 1.2 GPa, and 22.6% ± 0.75, respectively, with an average diameter of 314 ± 0.02 μm. The characterization results indicate that these treated fibers can be a good alternative natural reinforcement material in lightweight polymer composites or other composites for the building industry.
Abaca fibers were alkaline boiling treated with sodium hydroxide aqueous solution combined with impregnating in aluminum dihydrogen phosphate solution to improve the thermal shock resistance and reinforce shells for investment casting. The microstructure and thermal shock resistance of the treated fibers were analyzed, and their influence on the properties of reinforced shells was investigated. It is found that the hemicellulose and lignin at the surfaces of the fibers undergoing alkaline boiling were removed. A dense protective film was formed on the boiled fibers surfaces through impregnating in a solution of 15.0 wt.% aluminum dihydrogen phosphate. Moreover, the results demonstrated that the weight loss of the boiled-impregnated fibers reduces by 44.61%, compared to the raw fibers, indicating significantly improving the thermal shock resistance. Furthermore, the high-temperature strength of specimens reinforced with boiled-impregnated fibers of 1.29 wt.% reached a peak of 20.11 MPa, increasing by 68.12% compared to the unreinforced. And the alkaline boiled-immersed fibers reinforced shell occurred at elevated temperature a low deformation underweight of only 0.49%. Especially, the impregnated fibers with thermal shock resistance not only ensured good permeability of reinforced shells, but also enhanced the high-temperature cracking resistance capacity. This fully demonstrates the effectiveness of impregnating treatment in improving thermal shock resistance of fibers, and it is very promising to be applied in practical shell-making.
The present investigation aimed to understand the physico-chemical properties of new natural fiber extracted from Albiziaamara bark. The chemical composition, structural, thermal and tensile properties of Albiziaamara fibers (AAFs) were investigated. The results indicated that AAF had crystallinity index of (63.78 %), cellulose (64.54 wt. %), hemicellulose (14.32wt. %), lignin (15.61 wt. %), and low density (1043 Kg/m3). Thermogravimetric analysis show that AAFs were thermally stable up to 330.6°C and the functional groups of the AAFs were identified by Fourier transform infrared analysis. The AAFs exhibited tensile strength of 640±13.4 MPa with strain rate of 1.57±0.04%. This investigation reveal that AAFs could be a suitable material as reinforce agent in natural fiber-polymer composites for different applications.
Sugar palm fibres (SPF) are one of valuable natural fibres which are abundantly available in Malaysia as agricultural biomass. The aim of this study to investigate on the effects of alkali, silane, and combination between alkali (6%) and silane (2%) on physical and mechanical properties of sugar palm fibres to improve interfacial bonding of sugar palm fibres with thermoplastic polyurethane matrices. Scanning electron microscopy and Fourier transform infrared spectroscopy was used to observe the effectiveness of the alkali and saline treatments in the removal of impurities. Silane treated SPF exhibits better tensile strength than those of alkali, alkali-silane treated and untreated SPF. Droplet test indicates that the interfacial stress strength (IFSS) of alkali and silane treated SPF are enhanced whereas silane treated fibres exhibit highest IFSS. It is assumed that fibre treatments will help to develop high performance sugar palm fibre reinforced polymer composites for industrial applications.
Sugar palm fibre (SPF) was used to prepare composites with phenolic resin. The SPF underwent treatment with either sea water for 30 d or a 0.5% alkaline solution for 4 h. The composites contained 30% (vol.) SPF in a powdered form, and the composite samples were fabricated by a hot press machine. The effects of the fibre treatments on the mechanical (flexural, impact, and compressive), thermal, and morphological properties of the composites were analyzed. The SPF treatments considerably improved the mechanical properties of the composites compared with the untreated composite. The alkaline treatment resulted in the most improved flexural and impact strength of the composites. In contrast, the sea water treatment had the best results for improving the compressive strength. Morphological analyses indicated that the surface treatments improved the fibre-matrix bonding. The thermal degradation analysis showed that both the sea water and alkaline treatments of the SPF slightly affected the thermal stability of the composites. Consequently, SPF can be effectively used as an alternative natural fibre for reinforcing bio-composites.
In the present scenario, there has been a rapid attention in research and development in the natural fiber composite field due to its better formability, abundant, renewable, cost-effective and eco-friendly features. This paper exhibits an outline on natural fibers and its composites utilized as a part of different commercial and engineering applications. In this review, many articles were related to applications of natural fiber reinforced polymer composites. It helps to provide details about the potential use of natural fibers and its composite materials, mechanical and physical properties and some of their applications in engineering sectors.
Twenty First century has seen remarkable accomplishments in the environmentally friendly
technological world of material science through the biocomposites development. The aim of this
review article is to provide a comprehensive review of the foremost appropriate as well as widely
used natural fiber reinforced polymer composites (NFPCs) and its applications. In addition
presents summary of various surface treatments applied to natural fibers and its effect on NFPCs
properties. Natural fiber characteristics such as fiber type and fiber source as well as fiber
structure are reviewed. Physico-mechanical and thermo-chemical properties of the NFPCs have
been presented in this review. The impacts of various chemical treatments on the main properties
of NFPCs are analyzed. The impacts of fiber modification on the mechanical and thermal
properties of the natural fibers were demonstrated. The effects of various chemical treatments on
natural fibers that are used as reinforcements for thermosetting and thermoplastics were studied.
A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and
lower mechanical properties are shown. Impact of chemical treatment on the water absorption,
tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy and
biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in
automobile, construction industry and other applications are demonstrated. It concluded that
chemical treatment of the natural fiber improved adhesion between the fiber surface and the
polymer matrix which ultimately enhanced physico-mechanical and thermo-chemical properties
of the NFPCs
The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.
This study was to investigate the morphology, structure, and chemical properties of the Mendong fibers extracted from Mendong grass (Fimbristylis globulosa) in the form of raw and treated fiber by alkali-included chemical content and functional group and to evaluate the strength and properties of Mendong fibers compared with other natural fibers. These studies explore the chemical properties of the fiber including fiber composition and functional group by FTIR, mechanical properties of fiber, and the structural and morphological analysis of the fiber using SEM and XRD. The results showed that the chemical contents of Mendong fibers were 72.14% cellulose, 20.2% hemicellulose, 3.44% lignin, 4.2% extractive, and moisture of 4.2%–5.2%. Mechanical properties of the fiber were a strong character with tensile strength of 452 MPa, and modulus of 17 GPa. The structural properties of Mendong fiber such as crystallinity, crystalline index, microfibril angle, and crystalline size were 70.17% and 58.6%, 22.9°, and 14.3 nm, respectively. This fiber has competitive advantages compared with other natural fibers and can be developed further as a potential reinforcement of polymer matrix composites.
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The article throws light on the physical methods to modify natural fibers to be used in composites. Physical methods in natural fiber processing are used to separate natural fiber bundles into individual filaments and to modify the surface structure of the fibers so as to improve the use of natural fibers in composites. Steam explosion and thermomechanical processes fall in the first category while plasma, dielectric barrier techniques and corona fall in the second. The physical treatments have also been used to modify the thermoplastic polymeric films like polyethylene and polypropylene in a bid to impart reactivity. Reviewing such developments, the areas for further research are suggested.
Plant fibers are rich in cellulose and they are a cheap, easily renewable source of fibers with the potential for polymer reinforcement. The presence of surface impurities and the large amount of hydroxyl groups make plant fibers less attractive for reinforcement of polymeric materials. Hemp, sisal, jute, and kapok fibers were subjected to alkalization by using sodium hydroxide. The thermal characteristics, crystallinity index, reactivity, and surface morphology of untreated and chemically modified fibers have been studied using differential scanning calorimetry (DSC), X-ray diffraction (WAXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), respectively. Following alkalization the DSC showed a rapid degradation of the cellulose between 0.8 and 8% NaOH, beyond which degradation was found to be marginal. There was a marginal drop in the crystallinity index of hemp fiber while sisal, jute, and kapok fibers showed a slight increase in crystallinity at caustic soda concentration of 0.8–30%. FTIR showed that kapok fiber was found to be the most reactive followed by jute, sisal, and then hemp fiber. SEM showed a relatively smooth surface for all the untreated fibers; however, after alkalization, all the fibers showed uneven surfaces. These results show that alkalization modifies plant fibers promoting the development of fiber–resin adhesion, which then will result in increased interfacial energy and, hence, improvement in the mechanical and thermal stability of the composites. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2222–2234, 2002
The aim of this study is to investigate natural cellulosic fibers extracted from Tridax procumbens plants. The obtained fibers were alkali treated for their effective usage as reinforcement in composites. The physical, chemical, crystallinity, thermal, wettability and surface characteristics were analyzed for raw, and alkali treated Tridax procumbens fibers (TPFs). The test results conclude that there was an increase in cellulose content with a reduction in hemicellulose, lignin, and wax upon alkali treatment. This enhanced the thermal stability, tensile strength, crystallinity, and surface roughness characteristics. The contact angle was also lesser for treated TPFs which prove its better wettability with the liquid phase. The Weibull distribution analysis was adopted for the analysis of the fiber diameter and tensile properties. Thus the considerable improvement in the properties of alkali treated TPFs would be worth for developing high-performance polymer composites.
Designing environmentally friendly materials from natural resources represents a great challenge in the last decade. However, the lack of fundamental knowledge in the processing of the raw materials to fabricate the composites structure is still a major challenge for potential applications. Natural fibers extracted from plants are receiving more attention from researchers, scientists and academics due to their use in polymer composites and also their environmentally friendly nature and sustainability. The natural fiber features depend on the preparation and processing of the fibers. Natural plant fibers are extracted either by mechanical retting, dew retting and/or water retting processes. The natural fibers characteristics could be improved by suitable chemicals and surface treatments. This survey proposes a detailed review of the different types of retting processes, chemical and surface treatments and characterization techniques for natural fibers. We summarize major findings from the literature and the treatment effects on the properties of the natural fibers are being highlighted.
A bio-fiber, Pithecellobium dulce is abundantly available in all over the world. It has a higher cellulose content (75.15 ± 0.26 wt.%) and low density (865 ± 26 kg/m³). To acquire fundamental knowledge about Pithecellobium dulce Fibers (PDFs), its physicochemical, crystalline, tensile, and morphological properties were examined and compared with other plant fibers. The chemical functional groups and crystallinity index (49.2 ± 2.45%) of the PDFs were obtained via Fourier transform-infrared analysis and X-ray diffraction, respectively. The Thermogravimetric analysis results of PDFs exhibit thermal stability up to 170°C. The surface morphology of PDF was analyzed by scanning electron microscopy. The attained results conclude that PDFs are appropriate fibers for acting as reinforcement in manufacturing of green composite product.
Environmental friendly products are getting much attention nowadays because of their availability in abundance and their usability in many engineering applications. Natural fibers possess many unique properties which make them easily replaceable to man-made fibers. This review is envisioned to present the various extraction and chemical treatment methods and also focused on providing the information of the fibers in terms of their physical and chemical properties.
Natural fiber-reinforced polymer composites (NRPCs) are replacing many synthetic fibers because of their cheap availability and their hygienic, ecological, biodegradable, and sustainable properties. This work involved extraction of new cellulosic fibers from red banana peduncle (RBP) plant and investigated its chemical composition, physical, structural, thermal, and tensile properties. RBP fibers (RBPFs) have high specific strength and good binding properties due to their light weight andpresence of high cellulose (72.9 wt%), low lignin (10.01 wt%), and wax (0.32 wt%). X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) determined that RBPFs are rich in cellulose content with a crystallinity index (CI) of 72.3%. The density and diameter of the fibers were found to be about 0.896 g/cm³ and 15–250 μm, respectively. The fiber was thermally stable up to 230°C. Based on the results of this work, it seems that the properties of the fiber are a suitable candidate as a natural reinforcing material for the development of the biocomposite for potential applications.
The exploration of new natural fibers in the field of polymer composites can contribute to increase the invention of natural reinforcements and expand their use in possible applications. In the present work, the physico-chemical, thermal, tensile and morphological properties of Furcraea foetida (FF) fiber are presented for the first time. Chemical analysis results shows that FF has relatively higher cellulose (68.35%) with lower hemicelluloses (11.46%) and lignin (12.32%). Structural analysis of FF was conducted by Fourier transform infrared and ¹³C (CP-MAS) nuclear magnetic resonance spectroscopy. X-ray diffraction (XRD) analysis evidenced that FF has crystallinity index of 52.6% with crystalline size of 28.36nmThe surface morphology of FF was investigated by scanning electron microscopy (SEM), energy dispersive X-ray micro analyzer (EDX) and atomic force microscopy (AFM). The thermogravimetric analysis (TGA) reveals thermal constancy of the fiber upto 320.5°C with the kinetic activation energy of 66.64kJ/mol, which can be used as reinforcements in thermoplastic green composite whose working temperatures is below 300°C. The FF results were compared with those of other natural fibers, and indicated as a suitable alternative source for composite manufacture.
The world is in need of more eco-friendly material, therefore researchers around the globe focus on developing new materials that would improve the environmental quality of products. This need for new green materials has led to the utilization of composites made from raw natural fibers and polymer matrices, and this has become one of the most widely investigated research topics in recent times. Natural fiber composites are an alternative for replacing environmentally harmful synthetic materials and help control pollution problems. In addition, they are low cost, have better mechanical properties and require low production energy consumption. Also, using such materials in construction works, it is possible to improve the sustainability by eliminating construction wastes. Keeping in view all the benefits of natural fiber reinforced polymer composites, this paper first discusses various fabrication techniques employed for the production of these composites and then presents a detailed review of the research devoted to the analysis of their structure and properties by a variety of characterization techniques.
Napier grass is a high-productivity perennial grass that is a very important forage for animals in the tropics. In this research work, fiber strands from Napier grass were extracted and the effect of acetic acid treatment on their chemical composition, morphological and structural changes, and tensile and thermal properties was studied. The acid treatment was carried out using glacial acetic acid solution at three different concentrations (5, 10, and 15%) for 2 h. Chemical analysis indicated lowering of amorphous hemicellulose content on acid treatment. FT-IR spectroscopic studies revealed variation of functional groups on acid treatment. Scanning electron micrographs indicated roughening of the surface of the fiber strands due to the removal of the hemicellulose layer on acid treatment. X-ray diffraction analysis indicated an increase in crystallinity of the fiber strands on acid treatment. The thermal stability and tensile properties of the fiber strands increased on acid treatment. This fiber has competitive advantages when evaluated with other natural fibers and can be developed further as a potential reinforcement in polymer matrix composites. 2015
The mechanical, thermal, chemical, crystallographic and morphological properties of althaea fibres, extracted from Althaea officinalis L, was examined for the first time in this study. A. officinalis L. was obtained from Mordogan, Izmir (Turkey). After extraction process, lignin, cellulose and hemicellulose contents of althaea fibres were identified. Fourier transform infrared and X-ray photoelectron spectroscopy were utilized for surface functional groups of althaea fibres. By using X-ray diffraction analysis, CI value for althaea fibre is obtained to be 68%. The images of scanning electron microscopy were taken for observation of morphology of althaea fibres. The tensile modulus and tensile strength values of althaea fibre were obtained by single fibre tensile tests as 415.2 MPa and 65.4 GPa, respectively. Thermogravimetric analysis showed that thermal degradation of the fibre begins at approximately 220 degrees C. Besides, by pulling out the althea fibre from the embedded high density polyethylene, interfacial shear strength value was determined to be 8.16 MPa. The results suggest that the althaea fibre can be used in composite applications as a natural reinforcement material.
This paper provides a comprehensive overview on different surface treatments applied to natural fibres for advanced composites applications. In practice, the major drawbacks of using natural fibres are their high degree of moisture absorption and poor dimensional stability. The primary objective of surface treatments on natural fibres is to maximize the bonding strength so as the stress transferability in the composites. The overall mechanical properties of natural fibre reinforced polymer composites are highly dependent on the morphology, aspect ratio, hydrophilic tendency and dimensional stability of the fibres used. The effects of different chemical treatments on cellulosic fibres that are used as reinforcements for thermoset and thermoplastics are studied. The chemical sources for the treatments include alkali, silane, acetylation, benzoylation, acrylation and acrylonitrile grafting, maleated coupling agents, permanganate, peroxide, isocyanate, stearic acid, sodium chlorite, triazine, fatty acid derivate (oleoyl chloride) and fungal. The significance of chemically-treated natural fibres is seen through the improvement of mechanical strength and dimensional stability of resultant composites as compared with a pristine sample.
In this study the chemical treatment of sisal fiber using the combined alkali (NaOH) and clay is discussed. The purpose of this fiber treatment is to improve the fiber–matrix compatibility, interface strength, mechanical, thermal and water barrier properties. The phase change due to chemical treatment of raw sisal fiber was examined by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) methods. The result shows the presence of about 20 wt.% clays in NaOH–clay treated sisal fiber with 2.6× reduced water uptake and also with improved mechanical and thermal properties. Subsequently the treated and untreated fibers were reinforced in polypropylene (PP) matrix and the mechanical and thermal properties were examined. The result indicates that the fiber–matrix interface strength, adhesion, glass transition temperature and tensile properties of composites were improved in NaOH–clay treated fiber composites.
In this work, the variation of mechanical properties such as tensile, flexural, and impact strengths of roselle and sisal fibers hybrid polyester composite at dry and wet conditions were studied. The composites of roselle/sisal polyester-based hybrid composites with different weight% of fibers were prepared. Roselle and sisal fibers at a ratio of 1:1 had been incorporated in unsaturated polyester resin at various fiber lengths. When the fiber content and length of the roselle and sisal fibers were increased, the tensile and flexural strength of the composite increased. When the samples were subjected to moisture environment, decrease in tensile and flexural strength was observed. The maximum percentage of strength reductions in tensile and flexural strength were observed for the composites having the fiber length of 150mm and 30wt% fiber content. For impact strength, it was with the composites of 20wt% and 150mm at wet conditions compared to dry conditions. The percentage of strength reductions increased with fiber content and length in wet conditions. A scatter in the impact strength values was identified on both the conditions. The moisture absorption characteristics of the natural fibers are very important to produce the natural fiber hybrid composite materials with the positive hybrid effect. The experimental results are compared with theoretical and empirical or statistical results and found to be in good agreement.
The authors determined the density of various modified fibers using a density gradient column (xylene: carbon tetrachloride) at 32°C. Six specimens of each fiber were tested and the average value reported. The densities of capsularis and olitorius jute were found to be comparable. There was a small increase in the density of all the treated fibers compared to untreated jute, which could be due to the removal of less dense fats and waxes or hemilignin by the solvents used in the reaction medium or to filling up of the pores and voids on the fiber surfaces as a result of the treatment.
The development of high-performance engineering products made from natural resources is increasing worldwide, due to renewable and environmental issues. Among the many different types of natural resources, kenaf plants have been extensively exploited over the past few years. Therefore, this paper presents an overview of the developments made in the area of kenaf fiber reinforced composites, in terms of their market, manufacturing methods, and overall properties. Several critical issues and suggestions for future work are discussed, which underscore the roles of material scientists and manufacturing engineers, for the bright future of this new "green" material through value addition to enhance its use.
High grade bamboo dissolving pulp for cellulose acetate (named as acetate bamboo pulp) was prepared from bamboo Cizhu (Dendrocalamus affinnis) by oxygen-alkali pulping, xylanase and DMD (an intermediate product of the reaction of oxone with acetone) delignification treatments, and H2O2 bleaching. Its properties and structures were investigated by different analytical techniques, and compared with those of high grade hardwood dissolving pulp for cellulose acetate (named as acetate wood pulp), viscose bamboo pulp, and bamboo fiber for textile. Most of its properties are comparable with those of acetate wood pulp except ash contents and DCM (dichloromethane) extractive that are slightly high. Crystallinities and crystalline allomorphs of acetate bamboo pulp and the three samples were determined by FTIR spectroscopy, X-ray diffraction and solid state 13C NMR spectroscopy, and the results obtained by the three methods were coincident. Bamboo cellulose crystalline allomorphs are classified as Iβ-dominant type, and a higher lateral order index and a larger crystallite size for acetate bamboo pulp were found in spite of its crystallinity similar to acetate wood pulp. Different intermolecular hydrogen bond patterns are likely be responsible for the predominant crystalline fibrils in acetate bamboo pulp. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Natural-fiber-reinforced polymers can exhibit very different mechanical performances and environmental aging resistance depending on their interphase properties. A lack of good interfacial adhesion and poor resistance to moisture absorption make oil palm fibers less attractive as reinforcing agents. To improve the interfacial properties, oil palm fibers were grafted with different percentages of allyl methacrylate (AMA) in methanol. Darocur 2959 was added as a photoinitiator and initiated photochemical polymerization. The fiber surfaces were pretreated by an alkali, KMnO4, and dewaxed; this was followed by grafting with AMA to determine the effect of various surface treatments on the physicomechanical properties of grafted fibers. The alkali treatment increased the surface roughness with better impregnation of the polymer, which increased the tensile properties by about 20%. A minute amount of an additive (urea) and a coupling agent (silane) were added to the optimum formulations. These increased the physical properties of the grafted oil palm fibers because of increased crosslinking. The treated and untreated fiber samples were also subjected to various weather conditions, such as simulated weather, soil, and water aging, to determine the degradation properties, and lower losses were observed for the treated samples than the untreated fibers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Nowadays, the world faces unprecedented challenges in social, environmental and economical dimensions, in which the industrial design has showed an important contribution with solutions that provide positive answers regarding these problems. In particular, due to its relevance, the automotive industry confronts a moment of crises, and based on the ecodesign of products it has been transforming the challenges in opportunities. In this context, the use of natural fiber composites, produced in developing countries, have presented several social, environmental and economical advantages to design “green” automotive components. Thus, this work through LCA method demonstrates the possibility to use natural fibers through a case study design which investigates the environmental improvements related to the replacement of glass fibers for natural jute fibers, to produce a structural frontal bonnet of an off-road vehicle (Buggy). Results pointed out the advantages of applying jute fiber composites in Buggy enclosures.
The pyrolysis characteristics of three main components (hemicellulose, cellulose and lignin) of biomass were investigated using, respectively, a thermogravimetric analyzer (TGA) with differential scanning calorimetry (DSC) detector and a pack bed. The releasing of main gas products from biomass pyrolysis in TGA was on-line measured using Fourier transform infrared (FTIR) spectroscopy. In thermal analysis, the pyrolysis of hemicellulose and cellulose occurred quickly, with the weight loss of hemicellulose mainly happened at 220–315 °C and that of cellulose at 315–400 °C. However, lignin was more difficult to decompose, as its weight loss happened in a wide temperature range (from 160 to 900 °C) and the generated solid residue was very high (∼40 wt.%). From the viewpoint of energy consumption in the course of pyrolysis, cellulose behaved differently from hemicellulose and lignin; the pyrolysis of the former was endothermic while that of the latter was exothermic. The main gas products from pyrolyzing the three components were similar, including CO2, CO, CH4 and some organics. The releasing behaviors of H2 and the total gas yield were measured using Micro-GC when pyrolyzing the three components in a packed bed. It was observed that hemicellulose had higher CO2 yield, cellulose generated higher CO yield, and lignin owned higher H2 and CH4 yield. A better understanding to the gas products releasing from biomass pyrolysis could be achieved based on this in-depth investigation on three main biomass components.
Surface treatment is often necessary for strong composites. But the challenge for developing countries is to find chemicals and treatment procedures that are cheap and simple but maintain good composite properties. Mercerization followed by silane treatment of natural fibres is among the simplest and cheapest methods used to improve composite interfaces. This study investigates the effectiveness of this method to improve the bond between Agave americana fibres and post consumer HDPE. The influence of fibre extraction method, mercerization and mercerization followed by silane treatment on interfacial shear strength (ISS) and fibre properties is determined. The results indicate that ISS values are generally low but mercerization doubles the ISS values between Agave americana fibres extracted by traditional boiling of leaves and post consumer HDPE. Mercerization also improves fibre tensile and thermal properties. While triethoxyvinylsilane treatment of fibres after mercerization does not improve the ISS, it does not reduce it either, nor does it reduce tensile and thermal strengths of mercerized fibres. Fibres from non-boiled leaves resulted in poor fibre tensile strengths but improved ISS. There is a potential to use mercerization as cheap, simple technique to make Agave americana HDPE composites to provide cheap roof ceilings in Lesotho.
Composites materials based on cellulose fibres (raw or chemically modified) as reinforcing elements and thermoplastic matrices were prepared and characterized, in terms of mechanical performances, thermal properties and water absorbance behaviour. Four different cellulose fibres with different average lengths were used, namely avicel, technical, alfa pulps and pine fibres. Two thermoplastic polymers, i.e. low density polyethylene and natural rubber, were employed as matrices. Cellulose fibres were incorporated into the matrices, as such or after chemical surface modification involving three silane coupling agents, namely γ-methacryloxypropyltrimethoxy (MPS), γ-mercaptoproyltrimethoxy (MRPS) and hexadecyltrimethoxy-silanes (HDS). As expected, the mechanical properties of the composites increased with increasing the average fibre length and the composite materials prepared using both matrices and cellulose fibres treated with MPS and MRPS displayed good mechanical performances. On the other hand with HDS bearing merely aliphatic chain only a modest enhancement on composite properties is observed which was imputed to the incapacity of HDS to bring about covalent bonding with matrix.
Natural fibres have long been used as cost-cutting fillers in the plastics industry. Nowadays, they are considered to be a potential replacement of glass fibres for use in composite materials. However, although natural fibres have many advantages, the most important being their low cost and low density, they are not totally free of problems. A serious problem of natural fibres is their strong polar character, which creates many problems of incompatibility with most thermoplastic matrices (especially polyolefins). Surface treatments, although having a negative impact on economics, are potentially able to overcome the problem of incompatibility. The present study focuses on the development, optimisation and characterisation of two such treatments; acetylation and stearation. The two treatments were applied on two grades of flax fibres (green and dew retted flax), the results are discussed in terms of process variables, such as temperature, time of treatment, recycling of reactants, etc. Three characterisation techniques were applied on the treated and untreated fibres; X-ray diffraction, scanning electron microscopy, and inverse gas chromatography. It was found that both treatments result in a removal of non-crystalline constituents of the fibres, and alter the characteristics of the surface topography. It was also found that both treatments change the fibre surface free energy, with acetylation increasing it and stearation decreasing it.
Recently, the incorporation of lignocellulosic materials as reinforcing agents or as fillers in polymer composites has received an increased attention. Although natural fibres have a number of advantages over glass fibres, the strong polar character of their surface is a limiting factor, as compatibility with strongly apolar thermoplastic matrices is very low. Such problems of incompatibility may be overcome with fibre pre-treatments, which can enhance compatibility, albeit having a negative impact on the economics. In the present study, two fibre pre-treatment methods, acetylation and propionylation, were applied on flax, hemp and wood fibres. The effect of esterification between the acetyl/propionyl groups and the hydroxyl groups of the fibre was examined by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS), while its extent was assessed by titration. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the crystallinity and the surface morphology of the untreated and esterified fibres. The highest extent of the esterification reaction was achieved for the wood fibres due to their high lignin/hemicelluloses content. The two spectroscopic methods revealed that the fibre surface chemistry was altered after the treatments, as the results indicated that ester bonds are present on the fibre surface. The SEM results revealed that both treatments resulted in a removal of non-crystalline constituents of the fibres, possibly waxy substances, and alter the characteristics of the surface topography. It was also shown that the fibre crystallinity decreased slightly as a result of esterification.
The effect of chemical treatment on the tensile properties of sisal fibre-reinforced LDPE (low density polyethylene) composites was investigated. Treatments using chemicals such as sodium hydroxide, isocyanate, permanganate and peroxide were carried out to improve the bonding at the fibre polymer interface. The treatments enhanced the tensile properties of the composites considerably, but to varying degrees. The SEM (scanning electron microscopy) photomicrographs of fracture surfaces of the treated composites clearly indicated the extent of fibre matrix interface adhesion. It has been demonstrated that the CTDIC (cardanol derivative of toluene diisocyanate) treatment reduced the hydrophilic nature of the sisal fibre and thereby enhanced the tensile properties of the sisal LDPE composites. The SEM photomicrographs of the fracture surfaces have also shown that PE was highly bonded to the sisal fibre in CTDIC treated composites. The observed enhancement in tensile properties with the addition of small amounts of peroxides was attributed to the peroxide induced grafting of PE on to sisal fibre surfaces, as evident from the SEM photomicrographs of the fracture surfaces. It has been found that a low concentration of permanganate in the sisal-LDPE system during mixing considerably enhanced the mechanical properties. Among the various treatments, peroxide treatment of fibre imparted maximum interfacial interactions.
Industrial hemp fibres were treated with sodium hydroxide, acetic anhydride, maleic anhydride and silane to investigate the influence of treatment on the fibre structure and tensile properties. It was observed that the average tensile strength of sodium hydroxide treated fibres slightly increased compared with that of untreated fibres, which was believed to be as a result of increased cellulose crystallinity. The average tensile strength of acetic anhydride, maleic anhydride, silane and combined sodium hydroxide and silane treated fibres slightly decreased compared with that of untreated fibres, which was believed to be as a result of decreased cellulose crystallinity. However, the average Young’s modulus of all treated fibres increased compared with untreated fibres. This was considered to be as a result of densification of fibre cell walls due to the removal of non-cellulosic components during treatment.
- L Mohammed
- M N Ansari
- G Pua
- M Jawaid
- M S Islam
L. Mohammed, M.N. Ansari, G. Pua, M. Jawaid, M.S. Islam, A review on natural
fiber reinforced polymer composite and its applications, Inter.l J. Poly. Scie.
(2015), 243947.
- P Manimaran
- P Senthamaraikannan
- M R Sanjay
- M K Marichelvam
- M Jawaid
P. Manimaran, P. Senthamaraikannan, M.R. Sanjay, M.K. Marichelvam, M. Jawaid,
Study on characterization of furcraea foetida new natural fiber as composite
reinforcement for lightweight applications, Carbohydr. Polym. 181 (2018)
650-658.
D3379. Standard test method for tensile strength and Young's modulus for high modulus single-filament materials
- Standard AS