Advances in Polymer Technology

Polyolefins such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) are among the most widely used packaging materials in the cosmetic industry. Since these materials are in direct contact with cosmetic products, various components of the products are adsorbed to the packaging material’s surface and migrate within the amorphous regions of the polyolefin. This migration process, which occurs in both virgin and post-consumer recyclate (PCR) materials, can lead to deformation of the packaging. In this study, different types of virgin and PCR pellets were examined to investigate their interaction with cosmetic products and to understand the factors influencing the migration process. The migration of cosmetic oils was observed in all pellet samples, depending on the composition of the product and environmental conditions. The process was characterized by the weight gain of the plastic pellets and further identified through nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. Additionally, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) measurements were performed to analyze the polymer structure. Components with lower molecular weight (MW), high nonpolarity, and elevated temperatures were found to accelerate the migration process. Moreover, migration occurred more slowly from oil-in-water emulsions with larger droplet sizes compared to water-in-oil systems with smaller droplets. Among the different polyolefins, PP demonstrated a higher uptake of migrating components but at a slower migration rate compared to HDPE and LDPE. When comparing virgin and recycled polyolefins, it was observed that migration was consistently slower in virgin materials than in recycled ones. The ability of oils to migrate is influenced by the molecular structure of the polymers: high density, crystallinity, and low levels of branching reduce both the migration speed (MS) and the maximum saturation, as seen in virgin HDPE. In contrast, materials like LDPE, with a less dense polymer structure, exhibited higher MSs and saturation limits. As a control, polyethylene terephthalate (PET) was used, and it showed no migration due to the polymer’s high density.

This work presents an investigation on the quality of parts manufactured using fused deposition modeling (FDM), which is influenced by a large number of different elements. Some of which are based on the materials used in the production of the part, though others are rather pertinent to the process parameters. The manufacturing process and filament formulation has also a significant impact on the cost of the final product, as well as its physical, mechanical, and thermal properties. As the result, judicious combination of parameters can effectively act toward fine-tuning FDM toward three-dimensional printing (3DP) of pieces with quality fit-for-application. In this sense, the use of design of experiments (DOEs) is often needed for the purpose. Printing process parameters, including layer height, wall thickness, temperature, printing velocity, and tool path, have been discussed, in the understanding that 3DP time increases with decreasing layer thickness, and in turn increases production time and overall cost. A specific account is given on recent developments increasingly and more thoroughly focused on recognizing the impact of the process parameters and raw materials on the final product.

This review investigates the recent advancements aimed at optimizing the mechanical performance of three-dimensional (3D)-printed polymer matrix composites (PMCs), motivated by the need to overcome the inherent limitations of additive manufacturing (AM) in achieving desired mechanical properties. The study focuses on two primary areas: (1) microstructural refinements through strategic control of parameters such as reinforcement type, size, orientation, and interfacial properties and (2) processing enhancements involving the modification of build parameters, material formulations, and posttreatments. The review systematically analyzes the interdependencies between microstructure-property relationships and processing-performance characteristics. Key findings include an improvement of up to 50% in strength and toughness through optimized microstructure and printing techniques, which are compared with results from other studies that reported a maximum of 30%–40% improvement under similar conditions. The review also highlights the successful application of these approaches in various case studies, demonstrating their potential to substantially enhance the dimensional control and functional properties of 3D-printed PMCs, making them suitable for diverse applications ranging from aerospace components to flexible sensors. Despite these advancements, challenges such as performance consistency, part quality, and scalability remain, emphasizing the need for continued research to fully exploit the potential of 3D-printed PMCs.

Polymethyl methacrylate (PMMA) has garnered significant attention in the field of dentistry due to its wide applications. This paper proposes the incorporation of the nystatin coated copper oxide (CuO) particles having desirable conductivity and antifungal properties, as a filler in the PMMA denture to address their low thermal conductivity, low impact strength, low fatigue resistance, and microbial adhesion. The prepared nystatin coated CuO particles were characterized with several analytical techniques. The nystatin coated CuO particles were mixed in different ratios (0%, 1%, 2%, and 4%) in PMMA corresponding to groups C, E1, E2, and E3, respectively. The prepared samples of composite PMMA with nystatin coated CuO were evaluated to determine their transverse strength, impact strength, Vickers hardness (HV), and thermal conductivity. Furthermore, antifungal properties of CuO particles, nystatin coated CuO particles, and their acrylic composites were evaluated against Candida albicans. Scanning electron microscopy (SEM) analysis confirmed the particles’ spherical and irregular shapes. The particle sizes range from nano to micron level. Fourier-transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDX) analysis confirmed the coating of nystatin on CuO. X-ray diffraction (XRD) analysis showed the diffraction patterns and planes of CuO monoclinic shape structure. The composite prepared to have higher values of HV (19.53 ± 0.65, 20.16 ± 0.37, and 21.11 ± 0.75, respectively) as compared to the control. The impact strength values were measured high at 14.12 ± 5.55 kJ/m² for 2% containing nystatin coated CuO acrylic resins compared to control and other groups. The conductivity increased linearly with the addition of CuO particles. The addition of CuO particles causes a reduction in flexural strength as compared to the control group. As the concentration of nystatin coated CuO (1%, 2%, and 4%) in acrylic samples increased, the antifungal properties were improved. Thus, the incorporation of optimized concentrations of nystatin coated CuO particles in acrylic resin resulted in the improved mechanical, thermal, and antifungal properties.

With the increasing incidence of bird damage affecting the reliability of transmission lines, addressing bird pest control has become an important task for the operation and maintenance of transmission lines. A viable solution involves the application of spray-coated polyurea elastomer composite materials to insulate exposed conductive points and weakly insulated connection parts of transmission line towers. To improve the comprehensive performance of polyurea elastomers, in this study, a polyurea curing system was modified by incorporating aluminum oxide (Al2O3), silicon dioxide (SiO2), and (boron nitride) BN nanoparticles. An orthogonal experiment was designed to investigate the influence of different fillers on the comprehensive performance of polyurea elastomers. These nanoparticles partially filled the defects inherent in the polyurea and BN microparticles, improving the alternating current (AC) breakdown strength of these elastomers. Compared with filler-free polyurea elastomers, optimal performance of the polyurea elastomers was achieved when using 5 wt% Al2O3, 0.4 wt% SiO2, and 5 wt% BN, resulting in a 15.75% increase in the AC breakdown strength and a 10.00% enhancement in the thermal conductivity.

Poly(N-isopropylacrylamide) (PNIPAM) is a versatile polymer known for its phase transition properties, exhibiting a lower critical solution temperature (LCST) of approximately 32°C. Below this temperature, PNIPAM is hydrophilic, while above it, the polymer becomes hydrophobic, making it ideal for thermosensitive drug delivery systems (DDSs). In tissue engineering, PNIPAM provides a biocompatible, nontoxic and stimuli-responsive surface for cell culture. Its nontoxic nature ensures safety in medical applications. PNIPAM enhances biosensing diagnostics through its affinity for biomolecules, improving accuracy. Widely used in hydrogels, smart textiles, soft robotics and various medical applications, PNIPAM adapts to environmental changes. Its straightforward synthesis allows for the creation of diverse copolymers and composites, applicable in selective reactions and conjugations with fluorescent tags or chemical modifications. PNIPAM’s versatility extends to pH-responsive alternatives, broadening its application spectrum. Practical examples include phase separation in water treatment and cleaning processes. This discussion explores PNIPAM’s biomedical and drug delivery applications, particularly in cancer treatment, photothermal therapy (PTT) and photodynamic therapy (PDT), gene delivery and medical imaging. Additionally, it highlights PNIPAM’s noncancerous applications, such as small interfering RNA (siRNA) targeting of oncogenes and detailed imaging of deep and tumour tissues.

To improve the deteriorated performance caused by CO2 release during the curing process of traditional moisture-crosslinked polyurethane or polyurea and poor flame retardancy, this work realized an effective in situ crosslinking technique triggered by moisture for poly(urethane-urea) with intrinsic flame retardancy, through the incorporation of trimethoxysilane and phosphorus groups via a continuous two-stage process. Moisture-triggered crosslinking reaction of trimethoxysilane groups resulted in the establishment of a robust Si─O─Si network, as confirmed by Fourier transform infrared spectroscopy (FTIR) test. The structure transformation considerably enhanced the material’s strength, with the stress at break increasing from 1.0 to 3.2 MPa and modulus from 32.9 to 46.9 MPa. The flame retardant properties of PUUS1 (poly(urethane-urea) sample) were investigated through limiting oxygen index (LOI) and cone calorimeter (CCT) analysis, demonstrating satisfactory flame resistance, as evidenced by high LOI value of 29%, high char yield of 46.2%, and controlled smoke production. Combining thermogravimetric analysis-infrared spectrometry (TG-IR), X-ray photoelectron spectroscopy (XPS), and flame retardant performance, it is speculated that the generation of phosphorus-free radical scavengers in gas phase from diethyl bis(2-hydroxyethyl) aminomethyl phosphonate (DBHAP), coupled with the barrier effects of charred layer and distinctive Si─O─Si framework in condensed phase inhibited combustion and toxic gas emission. The results highlight the successful synthesis of a moisture-crosslinkable poly(urethane-urea) with intrinsic flame retardancy, promising for applications necessitating moisture-crosslinkable materials with superior flame resistance.

Chicken eggshells (ESs) consist of 96%–97% calcium carbonate, while about 3%–4% consists of organic substances, mainly in the form of protein-based membranes and occluded organic matter. Recently, ESs have been studied as a filler in polymer composite materials, which represents an innovative solution to address ES valorization. In this study, thermal and chemical treatments were investigated for membrane removal since the membrane may alter various properties when the ES fillers are added to the composite material. A nanoindentation method was used to measure changes in the ES mechanical properties. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier-transform infrared (FT-IR) spectroscopy were used to characterize the ES membrane removal through chemical treatment. The results showed that even at a heating temperature of 100°C, the ES mechanical properties were negatively affected, while a low concentration of bleach solution (25% bleach solution and 10 min of holding time) was able to remove the membrane without reducing the ES mechanical properties. The chemical treatment method offers a means for ES membrane removal while conserving the quality of the mineral fraction (calcite; CaCO3).

This article explores the multifaceted potential of pullulan-based films across food-packaging, pharmaceutical, biomedical, and cosmetic applications. In food-packaging, pullulan films serve as transparent, flexible, and high-oxygen barrier materials, effectively preserving the freshness and quality of a wide range of fruits and vegetables. Edible pullulan films extend the shelf life and enhance food safety, while active pullulan films inhibit microbial growth and oxidation, thus supports food preservation. In the pharmaceutical industry, pullulan-based films offer promising solutions for oral drug delivery, providing biodegradable and rapid disintegration for enhanced solubility and bioavailability of drugs. Additionally, due to their mechanical strength, biocompatibility, and antimicrobial properties, pullulan films demonstrate potential in wound dressings and tissue engineering applications. Furthermore, pullulan’s utility extends to the cosmetic industry, where it is used widely in various ingredients in skincare products, cosmetics, and personal care items. Its moisturizing, stabilizing, and film-forming properties make pullulan an attractive component in the industry. Future research directions should focus on cost-effective production methods and expanding industrial applications to further enhance their effectiveness and versatility. This in-depth analysis highlights the significant potential of pullulan-based films across multiple industries and underscores the importance of continued research and development efforts to fully unlock their diverse applications and benefits.

To achieve sustainable and energy-efficient CO2 capture processes, it is imperative to develop membranes that possess both high CO2 permeability and selectivity. One promising approach involves integrating high-aspect-ratio nanoscale fillers into polymer matrices. The high-aspect-ratio fillers increase surface area and improve interactions between polymer chains and gas molecules passing through the membrane. This study focuses on the integration of cellulose nanocrystals (CNCs) with an impressive aspect ratio of around 12 into rubbery polymers containing polyethylene oxide (PEO), namely PEBAX MH 1657 (poly[ether-block-amide] [PEBA]) and polyurethane (PU), to fabricate mixed-matrix membranes (MMMs). By exploiting the interfacial interactions between the polymer matrix and CNC nanofillers, combined with the surface functionalities of CNC nanofillers, the rapid and selective CO2 transport is facilitated, even at low filler concentrations. This unique feature enables the development of thin-film composites (TFCs) with a selective layer around 1 μm. Notably, even at a filling ratio as low as 1 weight percent, the resulting membranes exhibit remarkable CO2 permeability (>90 Barrer) and CO2/N2 selectivity (>70). These findings highlight the potential of integrating CNCs into rubbery polymers as a promising strategy for the design and fabrication of highly efficient CO2 capture membranes.

Deep-sea equipment is generally made of lightweight and pressure-resistant materials in order to meet the requirements of the actual work. In order to explore marine resources better, it is necessary to research lightweight buoyancy materials for loading on mining equipment. These buoyancy materials contribute not only to providing adequate buoyancy to the mining equipment but also to reducing economic expenses. In this paper, hollow glass microspheres reinforced epoxy hollow spheres (HGMSs-EHSs) were prepared by the rolling ball method using expanded polystyrene (EPS), epoxy resin (EP), and HGMS as raw materials. Epoxy syntactic foam (ESF) was manufactured by blending EP, curing agent, HGMS, and HGMS-EHS with molding method. Basalt fiber (BF) reinforced ESF was fabricated by adding BFs to form a fiber network inside the syntactic foam. The results revealed that the density and compressive strength of ESF increased progressively with the number of HGMS-EHS layers. The density and compressive strength of ESF decreased prospectively with the increase of the stacking volume fraction of HGMS-EHS. The density and compressive strength of ESF increased gradually with the enlargement of the length and content of BF. In the range of influencing factors mentioned above, the density of ESF remains around 0.3 g/cm³, which has a low density. When the number of layers of HGMS-EHS was two, the stacking volume fraction was 90%, the length of BF was 12 mm, the content of BF was 4%, the density of BF-ESF was 0.316 g/cm³, and the compressive strength was 6.93 MPa. The compressive strength of prepared buoyancy material can meet the pressure resistance requirements for operations in waters of a certain depth. With a density of only 0.316 g/cm³, it provides sufficient buoyancy to balance the gravity of the equipment. Compared with the current study, in this paper, BFs were used as the reinforcing phase to prepare solid buoyancy foam with low density and high compressive strength. The experimental results demonstrate that this economical fiber material can effectively improve the compressive strength of buoyancy materials. This buoyancy material may be suitable for loading on small equipment for extracting marine resources. This work provides a reference for the preparation of low-density solid buoyancy materials.

Enhancing the hydrophobicity of chitosan through acylation enables the encapsulation of water-insoluble drugs within the polymeric carrier cores. In this study, hydrophobically modified chitosan was synthesized by reacting low-molecular-weight chitosan with acyl chloride (C18–C24) using an agitation method under mild conditions. The structure of acylated chitosan was analyzed using FTIR and ¹H-NMR spectroscopy. The degree of substitution (DS) varied between 56% and 69% for different long-chain N-acylated chitosan, with N-stearoyl chitosan (ChC18) exhibiting the highest DS. The incorporation of capecitabine (CAP) into extended acylated chitosan increased particle size and decreased zeta potential. N-lignoceroyl chitosan (ChC24) exhibited the highest zeta potential value of −27 mV for 0.2 mg of CAP, indicating that the most extended acyl group was the most stable in the suspension. Transmission electron microscope images revealed that all acylated chitosan particles were spherical, with sizes ranging from 100 to 200 nm, and existed as stand-alone entities, indicating excellent stability in suspension. The loading of CAP increased in particle size but did not alter particle shape, except for ChC24, which exhibited agglomeration. SEM images revealed that the individual arrangement of particles in CAP-ChC18 made it more stable than other acylated chitosan. In contrast, the formation of clusters in CAP-ChC24 can be attributed to strong hydrophobic interactions. X-ray photoelectron spectroscopy results show that there is no nitrogen atom in ChC18, which means that the acyl group is oriented inward and bound to the stearoyl group via van der Waals forces. At different drug weight-to-carrier ratios, the encapsulation efficiency (EE) of CAP with varying acyl group lengths ranged from 85% to 97%. The drug loading (DL) capacity and EE increased as the amount of drug in the carrier increased. However, the length of the acyl group did not significantly affect DL and EE, even when the carrier-to-drug ratio was consistently maintained. Sustained release was observed in CAP-loaded ChC24, indicating a significant influence of the extended chain on chitosan. Consequently, extended N-acylated chitosan possesses enormous potential as a drug delivery system for CAP.

Process parameter optimization and selection play a crucial role in additive manufacturing, particularly in determining the quality and characteristics of the final product. Among these parameters, the infill pattern holds significant importance as it directly influences the structural integrity, production time, and material usage efficiency of the printed object. This research focuses on identifying the most suitable 3D printing infill pattern process parameters for thermoplastic polyurethane (TPU) material, specifically for applications in pipeline construction. The criteria considered for process parameter selection include printing time, ultimate tensile strength, ultimate flexural strength, and surface defect minimization. Various infill patterns, including hexagonal, line, solid, triangle (35°), triangle (55°), and line patterns, are evaluated as alternatives. Utilizing the multi-criteria decision-making technique known as analytical hierarchy process (AHP), a systematic approach is employed to determine the optimal printing pattern. The findings of this study reveal that the hexagonal infill pattern outperforms other selected patterns in terms of meeting the criteria set forth for pipeline construction using TPU material. This research contributes to enhancing the efficiency and quality of additive manufacturing processes in pipeline applications, emphasizing the importance of informed parameter selection for achieving desired performance outcomes.

Since polymer nanocomposites provide a versatile method to improve safety and protection in various applications, they are essential in tackling the problem of microbial infections. These nanocomposites are designed to actively prevent the growth of bacteria by including antimicrobial agents such as functional groups or nanoparticles. In the present article, copper oxide nanoparticles were synthesized via the green method using the solution method. The grafting of N-ethyl piperazine (NEP) to polyvinyl chloride (PVC) polymer was carried out to obtain NEP–PVC polymer using solution polymerization technique and further reacted with CuO nanoparticles to obtain polymernanocomposite which was characterized using FTIR and ¹H-NMR, SEM, TEM, DLS, and XRD. The comparison in the antibacterial activity of nanocomposite and the synthesized polymer was carried out to determine its efficacy against Escherichia coli and Staphylococcus aureus using the spread plate method. Our findings indicate that NEP–PVC-based nanocomposite after incorporating copper oxide nanoparticles has enhanced the antibacterial properties over NEP–PVC polymer, henceforth a promising candidate to be used in medical devices, food packaging, and surface coatings.

The aim of this work is a synthesis of suitable hydrogel to produce slow-release fertilizer using recycled cellulose which is obtained from waste paper. For this purpose, initially, we extracted alpha cellulose from waste paper and modified it to obtain carboxymethyl cellulose (CMC). Then, the CMC was converted to a suitable hydrogel through in situ graft copolymerization of acrylic acid and vinyl acetate in the presence of methylene bisacrylamide as a crosslinker. The various factors that affect hydrogel synthesis, such as the amounts of CMC, monomers, initiator, and crosslinker, were evaluated. In the optimized formulation, the weight ratio of monomers to CMC is 7, the molar ratio of monomers to each other is 1, and the crosslinker is used as 3 molar percent of monomers. The products were characterized using Fourier transform infrared, thermal gravimetric analysis, and scanning electron microscope analyses. The swelling behavior of the synthesized hydrogels was evaluated in different environments, such as distilled water, tap water, salt water, and different pH levels. The swelling ratio increases with an increase in pH level. Between the synthesized hydrogels, the best one was selected for slow-release fertilizer production and loaded with 20-20-20 fertilizer (NPK), and the release behavior was evaluated. In an alkaline pH, there was a long time for NPK release within a slow-release medium and even after 361 h, the release process was continued. Also, the performance of the fertilizer-loaded hydrogel in soil using water holding capacity and water retention ratio tests were evaluated.

Due to cross-linked structures, thermoset polymers cannot provide sufficient free volume for nanofillers to maneuver. Related composites are therefore governed by phase separation where filler-deficit regions become mechanical weakness. This work discovers that carbon nanotubes can be redispersed in thermoset polymer through heat treatments, thus, enhancing strength, thermal, and electrical conductivity of composites. Experiments carried out on a different thermoset matrix gives a similar trend where heating induced tube displacement is also verified by molecular dynamic simulations and piezo-resistivity tests.

To improve the electrical conductivity, mechanical properties, and antibacterial properties of conventional hydrogels while simplifying their preparation steps for better application in wearable, flexible sensors and biomimetic electronic skins. Polyvinyl alcohol (PVA) hydrogels were doped with an ionic liquid based on zinc chloride to synthesize improved hydrogels using the freeze-thawing method. It is found that the addition of ionic liquid based on zinc chloride to the hydrogel resulted in a significant increase in electrical conductivity. However, an excessive amount of these liquids led to a reduction in their mechanical properties. The results reveal that the balance between conductivity and mechanical properties can be achieved by controlling the concentration of the ionic liquid based on zinc chloride. The higher the ionic liquid concentration based on zinc chloride in the composite hydrogels, the better the conductivity performance. The addition of an ionic liquid based on zinc chloride resulted in a significant improvement in the conductivity performance of the hydrogels. Furthermore, excellent mechanical properties are maintained even at a mass ratio of 1 : 10 between ionic liquids based on zinc chloride and PVA hydrogels, and composite hydrogels exhibit excellent antibacterial properties.

This study aims to convert cotton-based post-consumer textile waste to biodegradable paper, which not only addresses the discarding of waste but also provides a second use of cotton. The post-consumer garment made with cotton was decolorized by stripping with concentrated NaOH and hydrose. Afterwards, it was chopped, ground, and treated with NaOH solutions. The paper was prepared through a wet-laid process by mixing carboxymethyl cellulose as a binder with chopped cotton textiles. To reduce water absorbency, the uncoated paper was coated with thermoplastic polyurethane (TPU) using heat pressing technique. The surface morphology and chemical structure of uncoated pristine paper, coated paper, and TPU films were conducted using SEM and FTIR studies. The tensile strength, contact angle, air permeability, and biodegradability tests were investigated according to the standard methods. The tensile properties of the papers were increased after TPU coating, accounting well around 28% compared to the uncoated pristine paper. The elongation at the break of the coated paper was at least 40% greater than the uncoated pristine paper. The coated paper displayed a higher water contact angle of 100°, even after 10 min. The lower air permeability was observed in the coated paper due to TPU film blocking the free spaces of the paper. The TPU-coated paper exhibited a weight loss of 48.1%–59.8% after 90 days, whereas the uncoated paper was 100% decomposed after 60 days. The burning of post-consumer cotton textile waste (PCCTW) paper generated ashes resembling those of burning paper, implying clean and environmental friendly biodegradation. The papers can replace the petroleum–plastic materials and serve as food and other packaging applications.

Epoxy polymer composites reinforced with fish scale-derived collagen (EFC) have garnered significant interest due to their potential for enhancing mechanical properties and environmental sustainability. In this study, we investigated the mechanical, thermal, and morphological characteristics of epoxy composites reinforced with varying concentrations of EFC (5%, 10%, 15%, 20%, and 25% wt). Tensile strength testing revealed an initial increase in Young’s modulus with 5% and 10% EFC concentrations, followed by a decrease at higher concentrations, attributed to agglomeration effects. Flexural strength (FS) exhibited a decreasing trend with increasing EFC content, while flexural modulus (FM) showed improvement up to 20% EFC loading. Scanning electron microscopy (SEM) analysis highlighted the distribution of collagen particles, with agglomeration observed at higher concentrations. Fourier-transform infrared spectroscopy (FTIR) spectroscopy indicated alterations in hydrogen bonding with the addition of EFC. Thermal analysis revealed a reduction at onset degradation temperature with EFC incorporation, attributed to poor dispersion and agglomeration effects, alongside a slight enhancement in thermal stability at higher concentrations. The study supports the sustainable use of EFC as a filler, by offering a renewable and eco-friendly alternative to reinforcing polymer composites.

Different samples of Asahi model SB-1000 polymer optical fibers arranged at different curvatures were aged to predict the loss of light transmission over 10 years. They were used in the FV0 detector of the ALICE experiment at the LHC. The fibers were exposed to 80°C, maintaining a relative humidity of less than 50% RH. The relative transmission loss was measured before and after aging. A maximum loss of 15% was found for 632 hr of aging, equivalent to 5 years for the ALICE experiment conditions considering thermal aging. This estimate is based on the Arrhenius model, using energy activation data from the literature. Complementary tests were done to analyze the fiber materials, such as XRD (WAX), FTIR, and mechanical tensile tests. For FTIR, no changes are found that indicate modifications in the chemical structure but in the physical properties of the materials. A study based on XRD shows that during the first 72 hr, changes in crystal size were observed, and consequently, there was a loss of transparency. Hence, mechanical tests indicate that the fiber decreases its Young’s modulus with longer aging times, making the material more tenacious to rupture.

This review provides a comprehensive overview of the multifaceted factors influencing TPE foam production, with a specific focus on the intriguing role of induced crystallization. TPE foams excel in versatility and cost-effectiveness, yet their production faces several challenges, that significantly impact their final characteristics. The examination encompasses a range of factors, including solubility, diffusivity, interfacial tension, rheology, foaming parameters, nucleating agents, and the intricate influence of induced crystallization on TPE foam structure and performance. In TPE, crystallinity can be induced through various means including gas sorption, stress concentration, extrusion, annealing, and self-nucleation. These induced crystals serve as nucleation sites for heterogeneous nucleation during foaming. The advancements achieved in polymer foam are thoroughly evaluated in terms of both progress and limitations, drawing insights from various research findings. Furthermore, the review examines recent developments and explores the effects of induced crystallization on TPE foam.

Numerous studies have examined rattan and date palm fibers separately, but none have combined both fibers in a single composite. This research focuses on creating novel hybrid composites using untreated and treated rattan and date palm fibers. Fibers were treated with 3%, 4%, and 5% NaOH solutions. Fiber diameters were measured microscopically. The NaOH treatment enhanced the tensile strength of the fibers. Untreated rattan, midrib, and spadix stem fibers exhibited tensile strengths of 18, 57, and 37 MPa, respectively. Polyester was used as the matrix, combined with fibers in weight fractions of 70 : 30, 75 : 25, and 80 : 20. All composites were made for 1 : 1 rattan–midrib and 1 : 1 rattan–spadix stem fibers. Composites containing 20% treated rattan–midrib fibers displayed the highest tensile and flexural strengths, measuring 13 and 39 MPa, respectively. Meanwhile, rattan–spadix stem composites achieved the highest tensile strength of 14 MPa at 30% treated fiber loading, and the highest flexural strength of 28.91 MPa at 20% fiber wt.%. Additionally, SEM images of the tensile fracture surfaces revealed voids, cracks, and impurities. The goal was to develop a new composite that provides a low cost, structurally sound, and environmentally friendly strong material suited for industrial, construction, and aviation applications.

The article provides a brief overview of the use of zeolites as environmentally safe anticorrosion pigments for organic coatings on metals. The number of studies on zeolite-based inhibiting pigments has increased significantly in recent years, due to the need to replace chromates and reduce the content of phosphate corrosion inhibitors. Based on the results available in the literature, an assessment was conducted on the inhibitory properties of complex zeolite pigments obtained by various methods. Emphasis is placed on the advantages and disadvantages of ion exchange modification of zeolites with inhibitory substances and mechanochemical synthesis of pigments. Zeolites have a wide perspective in anticorrosion technologies due to their porous structure, large surface area, high pore volume, and the ability to accumulate inhibitory ions and molecules. Such properties of zeolites make possible their use for the development of self-healing or “smart” polymer coatings. Considering the environmental safety of zeolites and their excellent thermal and chemical stability, anti-corrosion polymer coatings inhibited by zeolite pigments could become an effective environmentally friendly alternative to chromate-based protective coatings. The main trends and prospects for the development of research in this domain are presented.

In this study, zinc ferrite nanoparticles (ZnFe2O4 NPs) were incorporated into a polycarbonate/polyethylene oxide (PC/PEO) blend using the casting method. The resulting blends were subjected to comprehensive analysis using various techniques. X-ray diffraction (XRD) analysis revealed that the presence of ZnFe2O4 nanoparticles had a significant impact on the crystal structure of the PC/PEO blend, leading to a reduction in crystallinity. Fourier-transform infrared (FT-IR) measurements further confirmed the uniform distribution and compatibility of PC and PEO as polymer components, as well as their compatibility with the blend containing ZnFe2O4 NPs. The optical properties of the PC/PEO blend, including band gap and Urbach energy, were quantified using the Kubelka–Munk method. The incorporation of ZnFe2O4 NPs resulted in the formation of sub-band states between the valence and conduction bands, leading to a decrease in the band gap values. Field emission scanning electron microscopy (FESEM) analysis revealed a noticeable modification in the surface roughness, with the addition of ZnFe2O4 NPs resulting in a smoother surface texture. The electrical properties of the blends, including dielectric constant, dielectric loss, and AC conductivity, were measured. The addition of ZnFe2O4 NPs increased the dielectric constant (ε′) at lower frequencies, while it remained relatively stable at higher frequencies due to the localized charge carriers within the polymer blend. The higher values of ε’ observed at lower frequencies can be attributed to the movement of ions, which contributes to enhanced ionic conductivity. The magnetic properties of the blends were evaluated, demonstrating an increase in magnetic saturation upon the addition of ZnFe2O4 NPs. These findings provide valuable insights into the structural, optical, electrical, and magnetic characteristics of PC/PEO blends incorporated with ZnFe2O4 nanoparticles, thereby highlighting their potential for a wide range of technological applications.

This study is based on the utilization of fish scale-derived collagen (FSC) as a potential filler material in polyurethane foam (PUF) composites. The composites were prepared with varying FSC concentrations (2.5%, 5 wt%, and 10 wt%) with the standard PUF matrix, while calcium carbonates in the standard sample (STD) were completely substituted with 50 wt% of collagen. When examining the effects of collagen concentration on mechanical characteristics, complex correlations emerge between tensile strength, elongation, tear resistance, and ductility. The results reveal that the addition of 2.5 wt% FSC increased tensile strength by 12.66% during heat aging, while the addition of 5 wt% at standard temperature increased elongation by 6.65%. Under normal conditions, collagen significantly enhanced the material’s resistance to tearing, demonstrating its potential for long-term durability. Under typical conditions, tear resistance showed notable gains, increasing by 84.85% (50 wt% FSC) and 33% (10 wt% FSC), respectively. The tear resistance, however, diminishes under heat aging for all concentrations. Morphological assessments indicate a consistent closed cell structure across all samples, with collagen potentially contributing to reinforcement. The study supports the sustainable use of fish scale-derived collagen as a filler, addressing waste management challenges and aligning with principles of environmentally conscious material development.