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Pineapple Leaf Fibers and PALF-Reinforced Polymer Composites
Abstract
Pineapple leaf fibers (PALF) have long been known as textile materials in many countries. Despite being mechanically excellent and environmentally sound, PALF are the least-studied natural fibers, especially for reinforcing composites. This article presents a survey of research works carried out on PALF and PALF-reinforced composites. It reviews PALF extraction, fiber characterization, and PALF applications, modification of PALF, and manufacture and properties of PALF-reinforced composites. With increasing importance of pineapple and pineapple plantation area, value-added applications of PALF as reinforcing fibers in polymer composites must be developed in order to increase “resource potential” of pineapple and consequently energize the utilization of PALF.
... In addition, in a composite system, the reinforcing efficiency of natural fibers very much depends on their physical, chemical and mechanical properties. Sapuan et al. (2011) highlighted that some of the major drawbacks of natural plant fibers are "fiber non-uniformity, variation in properties, low degradation temperature, low Munirah, Rahmat & Hassan, 2007) microbial resistance and susceptibility to rotting". Moreover, they added that fiber extraction and processing techniques also strongly influence the final quality of the fiber and its cost and yield. ...
... and citrus. For example, in Malaysia, three species locally grown are the Queen, also known as Moris Gajah, Smooth Cayenne, also known as Sarawak pineapple, and Spanish or Josapine, which is found to be the most appropriate species for PALF extraction in terms of fiber quantity, ease of extraction, fiber fineness, mechanical and thermal properties (Sapuan et. al, 2011). In most cases, the pineapple leaves from the plantations are being wasted as they are cut after the fruits harvested before being either composted or burnt, causing environmental pollution (Sapuan et al, 2011). Traditionally, this material has also been predominantly used as textile materials, i.e. threads and textile fabrics such as d ...
... al, 2011). In most cases, the pineapple leaves from the plantations are being wasted as they are cut after the fruits harvested before being either composted or burnt, causing environmental pollution (Sapuan et al, 2011). Traditionally, this material has also been predominantly used as textile materials, i.e. threads and textile fabrics such as dresses, table linens, bags and mat in Philippines and textile materials in Indonesia and Thailand (Sapuan et al., 2011;Kengkhetkit & Amornsakchai, 2014). ...
There is an increasing interest worldwide in the use of Pineapple Leaf Fibers (PALF) as reinforcements in polymer composites, since this type of natural fiber exhibit attractive features such as superior mechanical, physical and thermal properties, thus offer potential uses in a spectrum of applications. PALF contains high cellulose content (between 70-82%) and high crystallinity. However, being hydrophilic, it posed a compatibility issue particularly in a hydrophobic polymeric matrix system. Thus, their shortcoming need to be addressed to ensure good interfacial bonding at the fibers/matrix interphase before their full potential can be harnessed. This chapter summarized some of the important aspects relating to PALF and its reinforced composites, particularly the main characteristics of the fiber, extraction and pre-treatment process of the fibers. Following this, discussions on the available fabrication processes for both short and continuous long PALF reinforced composites are presented.
... Pineapple leaves from the plantations are being wasted as they are cut after the fruits are harvested before being either composted or brunt. Burning of this beneficial agricultural waste causes environmental pollution [4]. ...
... NaOH reacts with hydroxyl groups of the cementing materials in natural fibers and brings on the destruction of the cellulear structure, thereby spiting the fibers into filaments. Hydrogen peroxaide (H 2 O 2 ) bleach improves PALF fineness by 5-6% but reduces the tensile strength by 40-45% [4]. Table 01 shows PALF chemical composition obtained from previous studies. ...
... Table 02 shows the different physical and mechanical properties of PALF that are collected from the articles of different researcher. [4,5,6,10]. Pineapple yarn and pineapple-jute-blended yarn are used for fashion fabric development, like fashion bag, curtain and furnishing fabrics and pineapple-acrylic-blended yarns are used to produce fancy apparel products [10]. ...
The demand of fibers is increasing with the growth of population. To
meet this demand the use of synthetic fibers is also increasing that is
great threat for our environment. The scientific community and
environmentalists are trying their best to replace the use of natural fiber in place of synthetic fibers. Among different types of natural fibers, Pineapple Leaf Fiber (PALF) shows outstanding fiber properties which are rich in cellulose, cost effective, eco-friendly having good fiber strength. In this study, the authors have tried to focus on the extraction process of PALF from leafs, characterization of PALF and its applications to produce different value added products.
... Nowadays, a growing interest has been shown by scientists and engineers in fully biobased and biodegradable polymer because of the advantages that this provides over conventional polymer material [1][2][3]. Recently, the development of biodegradable polymer has focused on natural fibre reinforced polymer composite material [1][2][3][4][5][6][7][8][9]. However, one major shortcoming of polymer material development is the manufacturing and processing temperature, where the natural fibre has a low degradation temperature while major resins available in the market such as polypropylene have higher melting temperatures [1,[4][5][6][10][11][12][13][14][15][16]. ...
... Recently, the development of biodegradable polymer has focused on natural fibre reinforced polymer composite material [1][2][3][4][5][6][7][8][9]. However, one major shortcoming of polymer material development is the manufacturing and processing temperature, where the natural fibre has a low degradation temperature while major resins available in the market such as polypropylene have higher melting temperatures [1,[4][5][6][10][11][12][13][14][15][16]. The creation of poly lactic acid (PLA) as a "green matrix" provides an alternative and a solution for the development of natural fibre polymer composites. ...
Environmental, global warming, renewability, recyclability, and biodegradability issues
have encouraged scientists and engineers to partially substitute petrochemical-based
polymers with green polymers such as natural fibre polymer composites. A major
drawback in the development of natural fiber polymer composites is the incompatibility
between the matrix and fibre processing temperature, given the high temperature of the
matrix based on petroleum and the low degradation temperature for natural fibre. The
creation of poly lactic acid as a “green matrix” provides an alternative and a solution for
the development of natural fiber polymer composites. In this work, the physical, thermal
and mechanical properties of PLA tapioca resin biopolymer derived from industrial
grade tapioca were reported in order to determine the optimum processing temperature.
A drying process, injection moulding and hot press process are involved in sample
preparation. A density test, hardness test, thermogravimetric analysis, and differential
scanning calorimetry have been conducted. Afterwards, a tensile test was performed
with samples at five different injection temperatures of 160°C, 165°C, 170°C, 175°C
and 180°C in order to determine the optimum processing temperature. The sample at
165°C shows the highest result of ultimate tensile strength with 14.904 MPa, and
320.564 MPa for the elastic modulus result. As a conclusion, 165°C was finalized as the
optimum processing temperature of PLA tapioca resin biopolymer for future application
in the research and development of natural fibre reinforced tapioca resin biopolymer
composite.
... Then, pineapple leaf spread on flat surface to remove outer skin of leaf using ceramic as shown in Fig. 2. Finally, extracted PALF was washed with water and dried under the sun or using the oven [2]. The manual extraction allows two types of fibres to be obtained from the leaves which are 75 wt% of large vascular bundles present in the top lamina and 25 wt% of fine fibre strands in the bottom lamina [31]. The process of extracting long fibres is great importance since the quality as well as the quantity of extracted fibres is strongly influenced by the method of extraction employed. ...
... However, PALF waste has been started to apply into several purposes included vermicomposting and animal pellets. Two types of fibres can be obtained by manual extraction process which are 75 wt% of large vascular bundles present in the top lamina and 25 wt% of fine fibre strands in the bottom lamina [31]. PALF only has 2.5-3.5% fibre covered by a hydrophobic waxy layer [19]. ...
Natural fibres have been acknowledged as potential material in many countries and widely used in vast application due to its specific properties and positive environmental impact. Selection of natural fibres for research or applications is categorized as per availability in particular region. Pineapple leaf fibres (PALF) are well-known fibre in South-East Asia. Pineapple leaf contains only 2.5–3.5% fibre, covered by a hydrophobic waxy layer. Suitable extraction method is the main challenged to obtain good quality PALF for future applications. The methods for PALF extraction were classified into three main categories, manual, mechanical and retting method. Physical and mechanical properties of PALF may differ from the other PALF due to the different extraction method. Extraction of thousands of tons of PALF can be done only after harvesting the fruit. The extraction method was chosen based on different criteria that involve cost of manufacturing, PALF stiffness, physical appearances and time consumption. This topic aims to indicate different extraction methods to obtain PALF and discussed on its physical and mechanical properties.
... The application of non-wood fiber as a reinforcing fiber is an important way to preserve the natural forest, since excessive utilization of wood fiber would lead to deforestation. So far, researchers have worked with sisal [13], abaca [14], banana [15] and pineapple leaf fiber [16]. Mengkuang leaf fiber (MLF) is a relatively new material as the reinforcing fiber. ...
Due to environmental concerns, plastic recycling and natural fiber composites have been given more attention lately. In Malaysia, mengkuang leaf fiber (MLF) has been identified as a potential candidate to be used as a reinforcing fiber. The combination of recycled polypropylene (r-PP) and MLF could result in an inexpensive and sustainable composite. However, the mechanical properties of this composite have not been fully studied. The aim of this work was to evaluate tensile, flexural and impact properties of r-PP/MLF composites with and without sodium hydroxide (NaOH) treatment and maleic anhydride-grafted polypropylene (MAPP). The composite consisted of 60 wt.% of r-PP and 40 wt.% of MLF. The composite was compounded by twin-screw extruder and test specimens were fabricated using an injection molding process. Generally, the tensile and flexural properties showed improvements, especially those with MAPP and alkaline treatment, compared to neat r-PP. Improvements in tensile strength and modulus of approximately 28% and 224% were achieved for r-PP/Treated MLF/MAPP composite respectively. However, an adverse effect was observed in the impact strength of the composite, which was expected due to the nature of short fiber employed in this work.
... It has also suitable textile properties and is capable of blending with jute, cotton, ramie and some other synthetic fibers [14]. Despite being mechanically excellent and environmentally sound, pineapple leaf fibers (PALF) are the least-studied of the above-mentioned natural fibers, especially for reinforcing composites [15,16]. Moreover, most of the works are concentrated mainly on the utilization without thoroughly knowing the properties. ...
The fundamental understanding of fibers, because of their polymeric nature, helps to improve the properties of the final product. This study presents an approach to examine the morphology, anatomy , cell wall architecture and distribution of lignin from pineapple leaf fiber by light microscopy, scanning electron microscopy with energy dispersive X-ray, transmission electron microscopy and Raman spectroscopy. Light microscopy and scanning electron microscopy revealed that the vascular bundle was randomly distributed across the transverse section of the pineapple leaf consisting of sclerenchyma, vessel , phloem and parenchyma cells. The fiber surface was covered with a rough hydrophobic layer composed of cutin, lignin, silica, waxes and a mixture of other cell wall materials. TEM investigations revealed the nanocomposite structure of the cell wall that were composed of typical primary and secondary cell wall layers. The topochemical distribution of lignin confirmed that the concentration of lignin at the cell corners was higher compared to compound middle lamella and secondary walls. This study helps to understand the fundamentals of the pineapple leaf fiber and can also help in the design of improved bio-based materials. Podstawowa ocena w³ókien lioeci ananasa jako wzmocnienia w biokompozytach Streszczenie: Omówiono podstawowe badania w³ókien lioeci ananasa przeprowadzone metodami: mikroskopii oewietlnej, skaningowej mikroskopii elektronowej z rozpraszaniem energii promieniowania rentgenowskiego, transmisyjnej mikroskopii elektronowej oraz spektroskopii Ramana. Badania obejmo-wa³y morfologiê, architekturê komórki, oraz zawartooeae i rozk³ad ligniny w lioeciu. Mikroskopia oewietlna i skaningowa mikroskopia elektronowa wykaza³y, ¿e wi¹zki naczyniowe s¹ losowo roz³o¿one w prze-kroju poprzecznym lioecia ananasa i sk³adaj¹ siê z komórek sklerenchymii, naczyñ ³yka i komórek mi¹¿-szu. Powierzchniê w³ókien pokrywa rogowa warstwa hydrofobowa, z³o¿ona z ligniny, krzemionki, wos-ków i mieszaniny innych materia³ów oecianek komórkowych. Badania potwierdzi³y nanokompozytow¹ strukturê oeciany komórkowej, któr¹ stanowi¹ typowe warstwy oecian komórkowych pierwotnych i wtór-nych. Stê¿enie ligniny w naro¿ach komórek by³o wiêksze ni¿ w oerodku lameli i oecianie wtórnej. Przepro-wadzone badania umo¿liwiaj¹ zrozumienie budowy i wynikaj¹cych z niej w³aoeciwooeci w³ókien lioeci ana-nasa i u³atwiaj¹ projektowanie polimerowych biokompozytów z udzia³em takich w³ókien. S³owa kluczowe: w³ókna lioeci ananasa, morfologia powierzchni lioecia, budowa anatomiczna, oeciana komórkowa, biokompozyty. The growing concern over increasing fossil fuel prices , global warming issues and greenhouse effects have stimulated a tremendous interest in the use of renewable materials that are compatible with the environment. Bio-mass is a readily available and low-cost feedstock that effectively stores energy, carbon, oxygen, and hydrogen from the environment via photosynthesis. Biomass feed-stocks are one of the few resources that can facilitate the large-scale, sustainable production of the substantial volumes of energy and materials needed to support the world's population and supplement non-renewable raw materials [1]. Recent advances in plant fiber development , genetic engineering and composite science offer significant opportunities for an exploration and development of improved materials from renewable resources for applications in biocomposites, pulp and paper, auto-798 2014, , 59 nr 11-12 1)
... Improvement on properties of PP can enhance its usage in engineering applications; in this case automobile. In achieving improvement in properties, additives are introduced which could be particulates [2][3][4]or fibers [5][6][7][8][9][10] or combination of both [11,12]. Natural fibers have been engaged by different researchers in enhancing properties of polymer [13,14]of which polypropylene is not excluded. ...
Coir-polypropylene composite was developed by the addition of coir fiber treated with 1.7 M NaOH solution for 24 hours at fiber loading 0 – 30 wt. % for automobile application. The fibers were cut to different length of 20 -50mm. Samples produced were subjected to test to examine tensile and flexural strengths and moduli, impact strength and hardness. Microstructural analysis was also carried out. Results obtained reveal rise in tensile strength with increasing fiber proportion up to 15 wt. % before a decline down to 30 wt. %. Increasing fiber length was observed to contribute to appreciation in strength up to 40 mm. Tensile modulus (TM) trended upward with in increased fiber loading up to 30 wt. % for length from 20 to 40 mm and for fiber cut to 50 mm, TM appreciated up to 15 wt. % before eventual depreciation. Results of flexural strength and modulus showed that flexural strength rose with increasing fiber loading up to 30 wt. % for coir fibers cut to 20 to 40 mm. Coir cut to 50 mm, gave increase up to 15 wt. % before eventual decrease in value. Flexural modulus rose from 0 to 30 wt. % for all fiber length except when 50 mm length was incorporated into the composite resulting lower modulus when compared with the ones recorded for coir of 40 mm length.
... Improvement on properties of PP can enhance its usage in engineering applications; in this case automobile. In achieving improvement in properties, additives are introduced which could be particulates [2][3][4]or fibers [5][6][7][8][9][10] or combination of both [11,12]. Natural fibers have been engaged by different researchers in enhancing properties of polymer [13,14]of which polypropylene is not excluded. ...
Coir-polypropylene composite was developed by the addition of coir fiber treated with 1.7 M NaOH solution for 24 hours at fiber loading 0 – 30 wt. % for automobile application. The fibers were cut to different length of 20 -50mm. Samples produced were subjected to test to examine tensile and flexural strengths and moduli, impact strength and hardness. Microstructural analysis was also carried out. Results obtained reveal rise in tensile strength with increasing fiber proportion up to 15 wt. % before a decline down to 30 wt. %. Increasing fiber length was observed to contribute to appreciation in strength up to 40 mm. Tensile modulus (TM) trended upward with in increased fiber loading up to 30 wt. % for length from 20 to 40 mm and for fiber cut to 50 mm, TM appreciated up to 15 wt. % before eventual depreciation. Results of flexural strength and modulus showed that flexural strength rose with increasing fiber loading up to 30 wt. % for coir fibers cut to 20 to 40 mm. Coir cut to 50 mm, gave increase up to 15 wt. % before eventual decrease in value. Flexural modulus rose from 0 to 30 wt. % for all fiber length except when 50 mm length was incorporated into the composite resulting lower modulus when compared with the ones recorded for coir of 40 mm length.
... and ash 0.9-2.7% [12]. ...
Pineapple leaf fiber (PALF) is one of the abundantly available agro-waste materials in Bangladesh. PALF-reinforced low-density polyethylene (LDPE)-based composites were fabricated by compression molding with randomly oriented fiber loading varying 10–60 wt%. In this study the influence of the fiber loading on the mechanical properties such as tensile, flexural and Izod impact was investigated. Water absorption tests of the composites were also carried out for determining water resistance properties of composites. Thermal properties of PALF were analyzed by thermogravimetry and derivative thermogravimetry. Scanning electronic microscopic studies were performed to understand the fiber–matrix adhesion and fiber breakage. To improve the compatibility between fiber and matrix, 50/50 PALF/LDPE composites were irradiated with gamma rays (Co-60) of doses where composites irradiated with 7.5 kGy dose showed the best results. Tensile properties of the composites were found to be improved significantly after gamma irradiation.
... Also, develop of cheap medium (Choonut, Saejong, and Sangkharak 2014) that would be used to convert invaluable product to valuable products as well as to clean the environment from wastes and reduce the pollution (Hossain, and Fazliny 2010). After the fibers extraction and process, the resulting mucilage can also generate numerous products in various areas, make them suitable for many industrial applications, including pharmaceuticals and animal feed, manufacture of yarn, woven fabrics, woven knitted, non-woven mats and handmade products, textile materials and reinforcing composites (Leao et al. 2015;Sapuan, Mohamed, and Ishak 2011). ...
The use of different lignocellulosic residues for the production of cellulosic ethanol is an alternative for the expanding demand of this fuel without increasing the planting area of traditional carbohydrate crops. One of the proposed alternatives is the use of pineapple leaf fibers (PALF) residues, which is a material rich in cellulose that can be used as raw material for second-generation (2G) ethanol production. In this study, the PALF was pretreated using an alkaline medium combined with a steam explosion and the 2G ethanol produSction was analyzed by two-way processes to enzymatic hydrolysis using separated hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF). Using SHF, the alcoholic fermentation process with addition of molasses provided good fermentability and can handle larger loads of carbohydrate in shorter fermentation time. The SSF was a better method for 2G ethanol production from PALF yielding 96.12%. Therefore, PALF is presented as good raw material for production of 2G ethanol, with all the environmental and social advantages of such approach.
Cellulosic materials derived from pineapple leaves fibers (PALF) which are being wasted after fruit harvested. There are two methods to extract cellulose from PALF. First methods were using sodium hydroxide (NaOH) 2% for alkaline treatment and bleached by sodium hypochlorite (NaClO) and buffer. Second method, cellulose was extracted using peroxyacetic acid delignification and bleached the sample in acidified pH 3 hydrogen peroxide solution. From X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) data’s, it is proven that both samples of cellulose have shown cellulose I structure.
The fundamental understanding of fibers, because of their polymeric nature, helps to improve the properties of the final product. This study presents an approach to examine the morphology, anatomy, cell wall architecture and distribution of lignin from pineapple leaf fiber by light microscopy, scanning electron microscopy with energy dispersive X-ray, transmission electron microscopy and Raman spectroscopy. Light microscopy and scanning electron microscopy revealed that the vascular bundle was randomly distributed across the transverse section of the pineapple leaf consisting of sclerenchyma, vessel, phloem and parenchyma cells. The fiber surface was covered with a rough hydrophobic layer composed of cutin, lignin, silica, waxes and a mixture of other cell wall materials. TEM investigations revealed the nanocomposite structure of the cell wall that were composed of typical primary and secondary cell wall layers. The topochemical distribution of lignin confirmed that the concentration of lignin at the cell corners was higher compared to compound middle lamella and secondary walls. This study helps to understand the fundamentals of the pineapple leaf fiber and can also help in the design of improved bio-based materials.
Pineapple leaf microfibers were firstly prepared using steam explosion, and all-cellulose composites were subsequently prepared using a surface selective dissolution process with the solvent of lithium chloride and N,N -dimethylacetamide (LiCl/DMAc). Mechanical properties and surface morphology of all-cellulose composites with immersion times of pineapple leaf microfibers in the solvent of LiCl/DMAc were investigated using tensile testing and scanning electron microscopy, respectively. The tensile strength of the all-cellulose composites with 120 min-immersion time was approximately 28 times higher than that of the pineapple leaf microfiber mats. These biocomposites made from pineapple leaf microfibers could be one of the potential alternatives to replace glass fiber reinforced composites.
The aim of this work is to compare properties of cellulose mats from pineapple leaf fibers with and without using the steam explosion method. Pineapple leaf fibers were divided into two groups. The first group was chemically treated with sodium hydroxide for 24 h, and directly used to prepare cellulose mats. The other group was pre-treated by steam explosion before treating with sodium hydroxide. Cellulose mats of microfibers were then prepared. The structure of pineapple leaf fibers was found to be changed due to the steam explosion observed by scanning electron microscopy. The effect of the steam explosion treatment was studied from chemical composition of steam-exploded fibers and unsteam-exploded fibers. Mechanical properties of mats of steam-exploded fibers were also investigated, compared to those of unsteam-exploded fiber mats. Mechanical properties of the mats of steam-exploded fibers were higher than those of the mats of unsteam-exploded fibers. This is due to the fact that the smaller-size fibrils can be found in the steam-exploded fibril mats.
Pineapple is grown worldwide and after every second or third fruit, the field is “knocked down,” and a new growing cycle begins. The residues left in the field are pineapple leaves and stems. Pineapple leaves are sources of high quality natural fiber which has long been used in crafts and textile but are still left underutilized. Considering the present situation, its availability and mechanical properties, pineapple leaf fiber (PALF) has many potential applications. Recently our research group has developed a method to extract short and fine PALF from leaf waste. PALF was used to reinforce different types of rubbers to produce rubber composites with very high stretching stress at low elongations. Rubber reinforcements using hybrid or combination of PALF/silica and PALF/carbon black were also studied and very promising results were obtained. For plastic reinforcement, both PALF and non-fibrous material (NFM) were tested on polypropylene in order to fully utilize the leaf waste. The use of PALF and NFM also offers a new way to ‘greening’ plastic composites for performance and cost effectiveness. In the last part, it is shown that nonwoven mats made from either whole ground pineapple leaves or PALF can be used as reinforcements for unsaturated polyester and acrylic resin.
The present article provides a concise summary of the research works covered in various areas of natural fibers, polymer matrix, and different techniques performed to enhance the properties of the composites, especially the interfacial properties. The discussion includes various composite manufacturing techniques with the optimum fabrication parameters resulted from the vast literatures in recent years. The mechanical properties such as tensile, flexural, fracture toughness, dynamic mechanical analysis, and thermogravimetric analysis studies are also presented in the discussion. Additionally, a brief review on natural fibers, their structure, mechanical properties, morphology, significant results from literatures emphasizing on the matrix and fiber modification techniques are also covered. The significance of the fiber matrix adhesion is discussed in detail focusing on the interface and interlaminar fracture behaviors along with the prospects for future advances.
The paper overviews the essential considerations in the manufacturing process of natural fiber composites which influence the performance of biocomposites. The evaluation of thermal properties of composites matrix and natural fiber chemical composition and physical properties appears to be necessary as the initial screening factors before the manufacturing process of biocomposites. On the other hand, considerations on fiber composition, type of manufacturing process and parameter used are seen as other crucial significant factors that need to be focused during the manufacturing of biocomposites. Moreover, the treatment used in the manufacturing process such as alkali treatment and coupling agent utilization should also be highlighted as additional important measures for better performance of biocomposites. In this review, all significant factors that influence the performance outcome of natural fiber composites are highlighted to provide the base-line source of literature for the manufacturing and production of composites sample. It is expected that the findings from the present study could further enhance the performance of natural fiber composites and able to become the preferred alternative or replacement for petroleum-based polymer in various industrial and commercial applications in the future.
Life cycle assessment (LCA) is a common tool to evaluate the life cycle environmental impact of products and processes. In the field of polymer composites, due to the ever growing environmental concerns, plant fibers such as flax, hemp, jute, kenaf, bamboo, coir, etc., have received great attention from researchers and industry worldwide, to replace traditional reinforcing fibers for polymer composite products. Plant fiber reinforced composites (PFRCs) have now become competitive engineering materials to partially or even fully replace traditional synthetic fiber based polymer composites, for example, glass fiber reinforced polymers (GFRP), and carbon fiber reinforced polymers (CFRP), and in many cases, PFRCs have been successfully industrially implemented such as in the automotive and sports industry. This chapter will discuss about the concept of LCA and the environmental impacts of PFRCs.
Development of pineapple leaf fiber (PALF)-based polymer composites has gain interests due to sustainable and environmental benefits when compared with synthetic-based non-degradable fibers. However, the hydrophilic PALF has poor interfacial bonding with the thermosetting and thermoplastic polymers which are hydrophobic. Moreover, this hydrophilic nature of PLAF leads to more moisture absorption rate, which results in degradation of overall properties. This issue can be addressed by modifying the surface of the fibers. Therefore, a comprehensive understanding of the effect of fiber surface modification on various properties and adhesion with polymers is a key for improving the performance of the PALF and its composites. In this context, the performance of surface modified PALF and its applications are elaborately discussed in this chapter.
Consumers are more aware of environmental impacts and climatic problems, which leads to a greater demand for products with technological innovations. Research has the aim to replace and reduce raw materials from fossil sources to renewable sources, such as the natural fibers. Natural fiber composites result from the blending of two materials: one is the plastic and the other a fiber, from agricultural waste in most of the cases. Compared to polymers from fossil sources, this new material has three main advantages: they have an environmental approved; low cost and its physical and mechanical properties are superior. The cultivation of this fruit is large in many tropical countries. After harvesting, the fruit and shoots are removed, and the rest needs to be cut and removed from the soil. This material, most leaves, becomes waste and goes to disposal. However, the use of pineapple leaf fibers as a raw material for natural fiber composites production helps to reduce the pollution caused by these residues and can increase the income of pineapple producers making a channel to new business. To have success in producing NFC, it is necessary to understand process techniques; to the adhesion between fiber and the polymer; the ratio of polymer and natural fiber; and the market (automotive, construction, etc.). But, after reading this chapter, it will be possible to conclude that there is a huge opportunity to improve the natural fibers market in front of the other reinforcements because of their properties.
Materials plays important role for survival of any manufacturing industry. Composite materials replace the conventional materials because of their high specific strength, strong damping capacity and high specific modulus. In modern era, natural fiber reinforced polymer composites came into light because of promising properties of natural fibers such as light weight, water resistance, high impact strength, environment friendly etc. In this study, different types of natural fibers that can be used as reinforcement in polymer composite are discussed. Various methods of production and steps involved in processing of natural fiber reinforced composite are presented. Then, mechanical and tribological properties of these composites are reviewed and presented. The different applications of natural fiber reinforced polymer composite are also discussed.
There is an increasing interest worldwide in the use of Pineapple Leaf Fibers (PALF) as reinforcements in polymer composites, since this type of natural fiber exhibit attractive features such as superior mechanical, physical and thermal properties, thus offer potential uses in a spectrum of applications. PALF contains high cellulose content (between 70-82%) and high crystallinity. However, being hydrophilic, it posed a compatibility issue particularly in a hydrophobic polymeric matrix system. Thus, their shortcoming need to be addressed to ensure good interfacial bonding at the fibers/matrix interphase before their full potential can be harnessed. This chapter summarized some of the important aspects relating to PALF and its reinforced composites, particularly the main characteristics of the fiber, extraction and pre-treatment process of the fibers. Following this, discussions on the available fabrication processes for both short and continuous long PALF reinforced composites are presented.
Natural fibers are of the good substitute sources for swapping synthetic fibers and reinforcing polymer matrices because of their contributions in maintaining of ecology, low energy requirement for processing and sustainability. The aim of this study is to characterize new fiber from Cyperus Dichrostachus A.Rich (CDA) plant. The CDA plant is a perennial non woody grass found in Ethiopian high lands and river basins. The fiber from this plant has good chemical composition of Cellulose (60.27%), hemicellulose (22.72%), lignin (16.59%) contents. It is light fiber having a density of 1010kg/m ³ and good tenacity behaviour of 105.76cN/Tex with low elongation of 4.88%. The thermal stability of Cyperus Dicrostachys A,Rich fiber (CDAF) was studied using TGA and DTG analysis and revealed that the cellulose degraded at a temperature of 377.1°C. Fourier transform-infrared spectroscopy analysis confirmed that CDAF is rich in cellulose content. Furthermore, the properties of CDAF ensured that it can play a vital role as new reinforcement material and best alternative in bio composite industries. This will give competitive advantages when evaluated with other natural fibers reveals that there are significant potential benefits in implementation of “cleaner production” in textile material production industries. Specifically, replacement of synthetic fiber source with renewable biomass will reduce the environmental impact of these fibers. The future study will entail on investigating the possible valorization route especially in paper board, composite reinforcement and bio composite applications.
Synthetic fiber composites are used in diversified applications because of their high strength-to-weight ratio. The energy associated with the production of synthetic fibers and their non-degradable characteristics is a major factor of concern looking from an environmental point of view. Natural fibers are derived from plants and animals, are biodegradable, and have properties similar to synthetic fibers. Pineapple leaf fibers (PALF) are obtained from pineapple leaves and can be effectively used as a reinforcement in the polymer matrix. PALF-based composite can be used in automobile, aerospace, sports, biomedical and furniture industries. Utilizing pineapple leaves for producing fibers which will be used in composites will not only reduce the associated environmental problems but also will give lucrative income opportunities to farmers and industries. This review paper deals with surface treatment methods for PALF. Mechanical and thermal properties of PALF reinforced composite are discussed in detail. The hybrid composite formed by PALF as one element is discussed. Overall, this review article highlights the previous work and identifies the gap for future research in the field of PALF reinforced composites.
Pineapple (Ananas comosus) leaf fibers (PALF), as a by-product of one of the largest productive systems in the agro-industrial field, appear as very promising for use in composites and for prospective applications in a number of fields, such as building and automotive. Despite these perspectives, the practical uses have been quite limited so far. This work investigates on this mismatch between the proposals and the concrete realization, suggesting that a number of options have been explored, yet limitations to industrialization are substantial at the moment. Considerations for overcoming this issue will include the disposition of fibers in the composite, the development of new matrices, the formation of hybrids and the interest of high added-value industrial and applicative sectors.
The main component in natural fibre is cellulose (C6H10O5)n. Cellulose from agricultural by-product is abundant, low cost, eco-friendly, biodegradable, and renewable. This research work was prepared alpha cellulose from pineapple leaf fibre (PALF), which obtained from the leaves of pineapple plant, Ananas comosus belonged to the family Bromeliaceae. The treated and untreated samples were characterized using X-ray diffraction (XRD).
Two chemical treatments were applied to hemp, sisal, jute and kapok natural fibres to create better fibre to resin bonding in natural composite materials. The natural fibres have been treated with varying concentrations of caustic soda with the objective of removing surface impurities and developing fine structure modifications in the process of alkalisation. The same fibres were also acetylated with and without an acid catalyst to graft acetyl groups onto the cellulose structure, in order to reduce the hydrophilic tendency of the fibres and enhance weather resistance. Four characterisation techniques, namely XRD, DSC, FT-IR and SEM, were used to elucidate the effect of the chemical treatment on the fibres. After treatment the surface topography of hemp, sisal and jute fibres is clean and rough. The surface of kapok fibres is apparently not affected by the chemical treatments. X-ray diffraction shows a slight initial improvement in the crystallinity index of the fibres at low sodium hydroxide concentration. However, high caustic soda concentrations lower the fibre crystallinity index. Thermal analysis of the fibres also indicates reductions in crystallinity index with increased caustic soda concentrations and that grafting of the acetyl groups is optimised at elevated temperatures. Alkalisation and acetylation have successfully modified the structure of natural fibres and these modifications will most likely improved the performance of natural fibre composites by promoting better fibre to resin bonding.
Studies undertaken by SITRA on the possible applications of jute and pineapple for technical textiles were reported. After a general survey of the materials used in technical textiles and application areas, there were statistics from David Rigby Associates, UK, recording 4% as the average growth rate for technical textiles from 1995-2005. The cultivation of jute and the pineapple plant were briefly described, with main structures and characteristics. A study on the development of a fine quality jute - JRC 321 - was undertaken by SITRA, and value added products made from yarns of JRC 321 jute fibres were fire-resistant upholstery for kitchens and acrylic winter jackets, both of which were described. Technical textiles using chemically treated PALF were discussed with the needle punched felts produced. More details were then supplied of end products, including industrial textiles, V-belt cord, conveyor belt cord, transmission cloth, air-bag tying cords and shoe laces. Overall it was concluded that jute and pineapple leaf fibres possessed good potential for manufacture into a number of technical textiles and value-added products.
A number of natural fibres are found in plenty in our country. However not all of them are put to full use in the textile field, while some of them are used in nontextile areas such as ropes, bags, huts, tents. PALF is one such with good single fibre tenacity and strength comparable with jute. There is ample scope for using PALF by blending with other fibres. An attempt is made in this paper to blend polyester staple and PALF to produce needlepunched nonwovens and to identify its uses as technical textiles. It is found that it can replace jute fibres and can combine with polyester fibre.
Around 60 million tonnes of flyash is being produced as a waste every year from different Thermal Power Plants in India. Attempts have been made to use flyash for its chemical composition for upgrading the wasteland for agriculture purposes. The long use of flyash may impart toxicity due to the hyperaccumulation of heavy metals in soil. The present paper deals with biologically modified form of flyash by practicing Vermitechnology. The Sisal green pulp, Parthenium and grass cuttings, were the major source of organic matter with combination of different concentration of flyash, though rich in primary, secondary and micronutrient may be lethal to the biological system if dumped repeatedly for increasing its agriculture productivity. Vermicompost treatments enhanced earthworm proliferation. The NPK content increases as compared to the standard manures. The biochemical analysis revealed the efficacy of the composts in terms of the microbial respiration and microbial number which shows declination with an increase in the concentration of flyash, but the difference was not at all very high as compared to the control except with parthenium where, the mortality was around 50% in 30% flyash. 10-15 folds proliferation had been observed in the compost made from sisal green pulp. Recent investigations highlighted the ability of earthworm Eisenia foetida to partially detoxify the toxic thermal power waste-flyash and transform sisal green pulp, parthenium and other organic rich waste into valuable vermicompost. Vermicomposting has been done to assess the impact of flyash in combination with the agricultural waste: Cowdung, Sisal Pulp, Parthenium, Grass cuttings and Eisenia foetida's ability to vermicompost. The biofertilizer value of the vermicompost produced, in terms of chemical, biochemical properties highlighted the beneficial effects of the waste treatments. The enrichment of nutrients in soil admixed with flyash after being processed for vermicomposting with different organic sources would have been a better formulation of flyash for bulk utilization in agriculture.
The increasing demand for producing durable construction materials is the outcome of the fast polluting environment. Supplementary cementitious materials prove to be effective to meet most of the requirements of durable concrete. Rice husk ash is found to be superior to other supplementary materials like slag, silica fume and fly ash. Due to its high pozzolanic activity, both strength and durability of concrete are enriched. Unlike other industrial by-products rice husk ash has to be produced out of the raw agricultural waste, husk. The quality of ash is greatly influenced by its method of production. To convert this ash into an active pozzolanic material, certain controlled conditions of production and processing methods have to be followed, which are yet to be fully understood and evolved. This paper presents various applications of rice husk ash in general and as pozzolana in particular. Works done on ash production methods have been critically reviewed. Possible areas of research have also been identified.
A sisal fibre has microstructures very different from those of synthetic fibres. The special microstructures consist of parallel cells and a cuticle-interface in the form of a continuous network around each cell. The flexible interface and solid cells play an independent role to toughen and strengthen the sisal fibre, respectively. Upon loading, the cell can behave in a brittle or a ductile fashion. The main failure mechanisms of a sisal fibre are the pullout and uncoiling of cells and the debonding of a not very strong interface/cell interface. Therefore, debonding of this interface represents the first initial damage of a sisal fibre composite.
Natural fibers are gaining progressive account as renewable, environmentally acceptable, and biodegradable starting material for industrial applications, technical textiles, composites, pulp and paper, as well as for civil engineering and building activities. The fibers of the plants, such as flax, hemp, linseed, jute, sisal, kenaf, yucca, abaca, or ramie, have outstanding mechanical properties. The tensile strength of the natural fibers, for example, is comparable to the strength of high-tensile steel. However, the properties of the natural product “bast fiber” depend on the variety grown, the growing conditions, and the technology of processing. Basically, there are two working principles to separate the bast fibers from the wood. The conventional method uses breaking rollers, which alternating bend, buckle, and soften the stalks. This method requires an intensive retting of the stalks before processing. The retting is effected by microorganisms which dissolve the lignin and pectin of the stalk. Modern technologies use swing hammer mills in most cases. The fiber decortication is effected by impact stress of the hammers directly on the surface of the straw stalks. This working principle ensures a complete separation of the fibers from the wood even when processing freshly harvested, nonretted plants. The effective mechanical separation of the fibers and the wood inside the decorticator simplifies the subsequent fiber cleaning. The processed fibers have a fineness ranging between 2.5 and 15 tex. The fiber length varies in an adjustable range from 50 to 200 mm after processing. This length meets the requirements of many industrial applications. The optimal fiber length for processing of composites is between 2 and 4 mm only. Such lengths are cut after the fiber cleaning using special fiber-cutting machines.
Plant fiber crops belong to the earliest known cultivated plants. They were cultivated for fiber production and were extensively developed through breeding and selection according to the human needs and values. These fibers used to possess great agricultural importance for the production of textiles until the late 19th century. However, the production of cheap synthetic textile fibers nearly terminated the production of traditional fiber crops, especially in Western Europe and North America. The increasing environmental awareness, growing global waste problems, the continuously rising high crude oil prices motivated governments to increase the legislative pressure; see, for instance, the European Union End-of-Life Vehicles* as well as Waste Electrical and Electronic Equipment (WEEE) Directive.† This in turn prompted researchers, industry and farmers to develop concepts of environmental sustainability and reconsider renewable resources. As a result of new legislation, the composite and polymer manufacturers, the processing industry and end-users but also the local communities will need to move away from traditional materials. New strategies will have to be developed for environmentally and economically viable materials manufacturing and processing, but also reuse and recycling. Composites with moderate strength will perform for many noncritical structural applications in the automotive and electronic, but also for packaging, housing and building industry. Green composites made entirely from renewable agricultural resources could offer a unique alternative for these applications. Plant fibers will be used as the reinforcing phase in such composites. They offer a real alternative to the commonly used synthetic reinforcing fibers, such as carbon, glass or aramid, because of their low density, good mechanical properties, abundant availability and problem-free disposal. Farmers might benefit from fiber crops because of their quick turnaround time. Fiber crops often produce very long fibers. The energy consumption for fiber crop cultivation, harvesting and fiber separation is much lower than the energy needed to manufacture synthetic fibers. However, there are also some drawbacks related to the use of plant fibers as reinforcement for polymers. Restrictions for the successful exploitation are their high moisture absorption, low microbial resistance and low thermal stability. Further research is necessary to gain a better understanding to develop sustainable economically viable materials processes for composites and to design innovative products of common interests.
Eco-friendly green/biocomposites were fabricated from chopped hemp fiber and cellulose ester biodegradable plastic through two process engineering approaches: powder impregnation through compression molding (process I) and extrusion followed by injection molding (process II). Cellulose ester, e.g. cellulose acetate (CA) plasticized with 30 wt% citrate plasticizer (CAP) was used as the matrix polymer for biocomposite fabrication. Intimate mixing due to shear forces experienced in process II produced superior strength biocomposites over their counterparts made using process I. Biocomposite fabricated through process II containing 30 wt% hemp natural fiber showed an improvement of storage modulus by 150% over the virgin matrix polymer. The coefficient of thermal expansion of the said biocomposite decreased from the CAP polymer by 60% whereas the heat deflection temperature improved by 30% versus the virgin bioplastic, indicating superior thermal behavior of the biocomposite. Plasticized cellulose acetate is proved to be much better matrix than non-polar polypropylene (PP) for hemp fiber (HF) reinforcements because of the better interaction of polar cellulose ester with the polar natural fiber. Fabricated through process II and with same content of hemp (30 wt%) the CAP-HF based biocomposite exhibited flexural strength of 78 MPa and modulus of elasticity of 5.6 GPa as contrast to 55 MPa and 3.7 GPa for the corresponding PP-HF based composite. The experimental findings of tensile modulus of the biocomposites are compared with the theoretical modulus using the rule of mixture. The fiber-matrix adhesion is evaluated through environmental scanning electron microscopy studies.
Graft copolymerization of acrylonitrile (AN) on chemically modified sisal fibers was studied using a combination of NaIO4 and CuSO4 as initiator in an aqueous medium in the temperature range of 50–70°C. Effects of reaction medium, variation of time and temperature, concentration of CuSO4, NaIO4 and AN, and the amount of sisal fiber on the percentage of graft yield have been investigated. Water absorption (%) and tensile properties such as tensile strength, Young's modulus and extension at break of untreated, chemically modified and AN-grafted sisal fibers were evaluated and compared. FTIR spectroscopy and scanning electron microscopy (SEM) of the chemically modified and AN-grafted sisal fibers have been carried out.
A method for separating decorticated bast skin into individual fibres, comprising maintaining decorticated bast skin in a closed container in the presence of at least one enzymatic and/or chemical retting agent for a period sufficient for at least a portion of the fibre bundles to separate into individual fibres.
It is well known that natural fibers impart polymeric matrix composites high specific stiffness and strength, a desirable fiber-aspect ratio, and biodegradability. Also, cellulosic fibers are readily available from natural sources, and most importantly, they have a low cost per unit volume. One difficulty that has prevented a more extended utilization of natural fibers is the lack of good adhesion to most polymeric matrices. The hydrophilic nature of natural fibers adversely affects adhesion to a hydrophobic matrix, resulting in poor strength properties. In order to give an overview of the problems that have to be overcome when using a natural fiber, a review of their nature and configuration is made.
In previous works, the processing of plasticized PVC reinforced by cellulose nanocrystalline whiskers has been presented, as well as its mechanical behavior in the linear viscoelastic domain. The purpose of this work is now to evaluate and model the plastic behavior of such material. Compression tests are performed in the glassy state. The "quasi-point defect" or "qpd" theory, developed by Perez et al. and previously used for the analysis of the composite mechanical behavior in the linear domain, is now applied to the nonlinear domain to account for the matrix behavior. Then, an incremental approach, using the relationship between the matrix and the composite modulus deduced from DMA experiments, is used to predict the composite behavior by calculating the instantaneous modulus of this composite along its load path. Moreover, a simple model is introduced to account for the stress concentration created by the whiskers in the matrix. It explains the disappearance of the stress peak on the stress-strain curve at increasing whisker contents. Finally, the damage phenomena are discussed, highlighted by successive compression tests. (C) 2000 John Wiley & Sons, Inc.
Concern about global warming has led to renewed interest in the more sustainable use of natural fibres in composite materials. This important book reviews the wealth of recent research into improving the mechanical properties of natural-fibre thermoplastic composites so that they can be more widely used. The first part of the book provides an overview of the main types of natural fibres used in composites, how they are processed and, in particular, the way the fibre-matrix interface can be engineered to improve performance. Part two discusses the increasing use of natural-fibre composites in such areas as automotive and structural engineering, packaging and the energy sector. The final part of the book discusses ways of assessing the mechanical performance of natural-fibre composites. With its distinguished editor and team of contributors, Properties and performance of natural-fibre composites is a valuable reference for all those using these important materials in such areas as automotive and structural engineering.
Sodium silicate is manufactured adopting several processes. Our experimental work is the preparation of sodium silicate from rice husk. Rice husk is available in abundance from the modern rice mills. Our work involves utilization of this waste material into a valuable product. This process, involving mainly alkali treatment, is found to be most economical and viable one.
Spinning, weaving and processing of fibres and fabrics made out of leaf fibres is a new concept of recent origin, where pineapple fibre (PALF) is gaining considerable importance. SITRA, of Coimbatore with UNDP assistance has taken up a project, and has successfully spun these fibres. Even though this fibre could not be blended either with cotton or with synthetic fibres due to its long length and high fibre weight, it is expected that in the nearer future these fibres will be exclusively used for a specific purpose, along with cotton either in warp or in weft to produce carpet type fabrics and in fact, handloom weavers of the SALEM region, of Tamin Nadu have started making carpets using raw spun PALF fibre. It is high time for researchers to look into the details of chemical processing, dyeing behaviour, strength losses and fibre degradation of PALF which will determine the feasibility of producing blended fabrics using pineapple yarns, and this will help chemical processors to draw their own process sequence for processing such blended fabrics/yarns.
After decades of high-tech developments of artificial fibres like carbon, aramid and glass it is remarkable that natural grown fibres have gained a renewed interest, especially as a glass fiber substitute in automotive industries. Fibres like flax, hemp or jute are cheap, have better stiffness per unit weight and have a lower impact on the environment. Although automotive takes the lead in the revival of natural fibres, applications are mainly restricted to upholstery applications where acoustic and thermal insulation, low cost and an environmental image are advantages. Structural applications are rare since existing production techniques are not applicable and availability of semi-finished materials with constant quality is still a problem. But on the research and prototyping level it has been shown meanwhile that in structural applications natural fibre composites have the potential to become a substitute for glass composites. Within the Dutch R&D program 'Biolicht', production techniques with appropriate semi-finished materials were developed in order to manufacture structural components with techniques like SMC and RTM. This article describes the results of that research program.
High Density Polyethylene and long sisal fibers were used to produce the composite. Fibers were treated with NaOH or just washed with water. Samples were irradiated to integral doses of 10, 25, 50, 60 and 70 KGy, with a dose rate of 4.8 KGy/h, in oxygen atmosphere and ambient temperature. The tensile and impact properties were determined and the morphology of the system was studied. It was observed that the Young's module increased approximately 29% when fibers were added to the HDPE, independently of the treatment that was applied to the fibers. Additionally, it was observed that at low irradiation dose (0 - 25 KGy), the composite with NaOH treated fibers had better mechanical properties than the material with fibers washed with water. However, at moderate irradiation doses (25 - 70 KGy) the behavior was completely the opposite. This indicates that the fibers washed with water are more stable than those treated with NaOH, at moderate radiation dose. While, at low dose, the interfacial adhesion is more effective when the fibers were treated with NaOH, due to the elimination of lignin, wax and hemicellulose of the surface of the fibers.
Pineapple leaf fibers (PALF) are of little use in Malaysia despite being mechanically and environmentally sound. Untreated and bleached PALF were used to reinforce vinyl ester (VE) utilizing hand lay-up (HLU) and liquid compression molding (LCM). Mechanical properties, water absorption and thermal stability were compared to neat resin and glass fiber-reinforced VE. Adding PALF reduced machinability dramatically while generally enhancing VE mechanical properties. Bleached PALF improved fiber-matrix adhesion compared to untreated PALF. Molding resin and composites with pressure enhanced water resistance by 2 - 3 times. Water absorption increased with increasing PALF while bleached PALF somewhat decreased water absorption due to improved wetting. PALF slightly reduced VE thermal stability although enhancement is expected upon using bleached PALF. Molding pressure has no effect on thermal stability of VE and PALF-reinforced VE. This study indicated that PALF may be used to reinforce VE to produce composites utilizing LCM and inexpensive bleach pretreatment.
The objective of this study was to investigate the mechanical properties (% elongation and puncture strength) of poly(D,L-lactide) (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) films as a function of exposure time to an aqueous medium and to correlate the mechanical properties to the degradation/erosion of the polymer as a function of the type of polymer [PLA, weight-average molecular weight (MW) 270,300, or PLGA 50:50, MW 56,500], the type of plasticizer [(triethyl citrate (TEC) or acetyltributyl citrate (ATBC)], and the exposure time to pH 7.4 phosphate buffer. The glass transition temperature of the films was measured by differential scanning calorimetry (DSC), the molecular weight by size exclusion chromatography (SEC), and the polymer erosion and hydration gravimetrically. The mechanical properties were strongly affected by the type of polymer and plasticizer. PLGA films showed a faster loss of mechanical integrity. TEC, the water-soluble plasticizer, leached from the films, resulting in major differences in the mechanical properties (flexibility) when compared with films plasticized with the more permanent, water-insoluble ATBC. A significant difference in MW decrease was seen between plasticizer-free and plasticizer-containing PLA films, but not for PLGA films. Plasticized PLA films, which were above their glass transition temperature in the rubbery state, showed a faster decrease in MW than plasticizer-free PLA ones, which were in the glassy state. The plasticizer addition to the lower MW PLGA did not enhance the polymer degradation; the plasticizer-free PLGA was already in the rubbery state. Major differences between the two polymers were also seen in the mass loss and the water uptake studies. After 4 weeks, the mass loss was between 2.6 and 7.0% and the water uptake between 10.1 and 21.1% for PLA films, whereas for PLGA films, the mass loss was between 40.3 and 51.3% and the water uptake between 221.9 and 350.6%. 2000 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 89:1558–1566, 2000
The social and economic benefits of plastics in packaging are considered and for technical and environmental reasons a return to traditional materials, as advocated by some environmentalists, is considered to be unrealistic. The main advantages of plastics is their lightness and resistance to water and water-borne microorganisms. However, these advantages in use are the main reasons for their obtrusive nature on the sea shore and in the countryside where they appear in large quantity as litter. It is therefore proposed that degradable plastics have a role to play in the ‘systems’ approach to packaging waste and litter.
The performance of degradable plastics in the context of their intended purpose and the environments in which they are required to degrade is considered and it is argued that, if they are carefully designed to degrade in a controlled manner, they should cause no problems during use or in any of the alternative waste management procedures. These include municipal composting, materials recycling, incineration, pyrolysis and sanitary landfill.
The aim of this study was to investigate the effects of compatibilising agent and surface modification of short pineapple leaf fibre on physical properties of short pineapple leaf fibre reinforced high impact polystyrene (HIPS) composites. The purpose of using the compatibilising agents in this study was to modify the HIPS which include the polystyrene-block-poly (ethylene-ran-butylene)-block-poly(styrene-graft-maleic anhydride) and poly(styrene-co-maleic anhydride). Meanwhile, the alkali treatment was also used to modify the natural fibre surface of short PALF. The results have shown that adding compatibilising agent has improved the physical properties of the composites more effectively than by only using alkali treatment to modify the natural fibre surface.
The effect of hydrogen peroxide bleaching on pineapple leaf fibre (PALF) and its yarn were investigated. Peroxide bleaching of PALF improved its fineness by 5-6% but reduced the tensile strength by 40-45%. Bleached PALF when spun into yarn produced a more uniform, more extensible but lower strength yarn than the control raw PALF yarn. Raw PALF yarn on bleaching showed high extension, low strength and more irregularity than the control raw yarn. The pliability of PALF yarn improved after bleaching in fibre as well as in yarn state.
From the advent of number of rice milling industry, husk a by product obtained from rice is generally utilized for the energy value. Large quantity of ash from the combustion of husk is a matter of serious concern. There is hardly any utilization in India. The concrete actions and thoughts are lacking towards its utilization. This paper attempts to review the various applications towards optimum utilization of husk ash.
The analysis of variation in thermal conductivity and thermal diffusivity of Banana fiber reinforced polyester composites caused by the addition of glass fiber have been presented in this paper. The composite shows an increase in thermal conductivity in comparison to matrix. However, the thermal conductivity of the composites with increased percentage of glass fiber, decreases in comparison to composite of pure banana fiber. It is minimum when glass fiber fraction is 11 % in the composite. The decrease in thermal conductivity values with increasing percentage of glass fiber from 3% to 11 % in the composite is due to fiber/ matrix de-bonding, fiber pull out and matrix fracture. Increase in thermal conductivity at 15% of glass fiber can be attributed to a change in the energy dissipation mechanism. Y. Agari model is used to evaluate the thermal conductivities of the fibers in the hybrid composite.
Surface activation is a simple method for altering the surface properties of both natural and synthetic fibers. These treatments generally result in improved compatibility and provide superior bonding, adhesion and strength properties in composite structures. The activation methods described in this chapter are restricted to chemical and electricdischarge treatments of natural and synthetic fibers. To properly assess changes at the fiber surface due to surface activation it is necessary to employ the appropriate analytical methods for surface characterization. A very brief review of the methods available for surface characterization is given and three analytical methods applicable to fibers are described; namely, the Wilhelmy wetting method, ESCA and inverse phase chromatography.
For many biomedical, agricultural, and ecological purposes, it is desirable to have a biodegradable plastic that will undergo degradation in the physiological environment or by microbial action in the soil. Great effort has been devoted to enhance the biodegradability of plastics, and attempts have been centered mainly around the following areas: new biodegradable polymers, modification of natural polymers, modification of synthetic polymers, and biodegradable polymer composites. In search of biodegradable polymers based on renewable resources, attention has been focused on biopolymers as starting materials. Plant protein is one of the major biopolymers in crops. It is a renewable and biodegradable biopolymer. There are relatively few applications for plant protein as materials. Fibers and plastics have been produced from plant proteins such as casein, zein, glycinin, and arachin. Among these plant proteins, soy protein has the advantage of being economically competitive.
