Journal of Applied Research in Chemical-Polymer Engineering

Abstract Research subject: Cellulosic nanomaterials, including cellulose nanocrystals, cellulose nanofibers, and bacterial cellulose, have attracted significant attention as reinforcing agents in epoxy matrices due to their low density, high mechanical strength, suitable elastic modulus, and renewable nature. However, the inherent hydrophilicity of cellulose nanoparticles and their poor interfacial adhesion with epoxy resins impose critical limitations on the mechanical and thermal performance of epoxy nanocomposites. Consequently, surface modification of cellulosic nanomaterials has emerged as a key strategy to enhance interfacial compatibility and improve the overall properties of epoxy-based nanocomposites.
Research approach: This study presents a comprehensive review and analysis of research published between 2023 and 2025, focusing on various surface modification techniques for cellulosic nanomaterials. These techniques include silane treatments, hydrophobic coatings, esterification reactions, and other chemical modifications. The primary objective of these approaches is to reduce the hydrophilicity of cellulose nanofibers, enhance interfacial adhesion between the reinforcing phase and the epoxy matrix, and promote uniform dispersion of nanomaterials within the nanocomposite structure.
Main results: The results of this study demonstrate that surface modification of cellulose nanoparticles significantly enhances their interfacial interactions and dispersion within the epoxy matrix, leading to a noticeable increase in the onset and peak thermal degradation temperatures, a reduction in the thermal degradation rate, and a measurable increase in char residue at elevated temperatures. Improved dispersion and reduced agglomeration of nanofibers result in substantial enhancements in mechanical properties, including tensile strength, elastic modulus, and stiffness, along with improved fracture behavior and effective inhibition of crack propagation. Quantitative analysis indicates that the surface modification method, functional group chemistry and density, nanofiber loading level, and dispersion uniformity play decisive roles in optimizing both thermal stability and mechanical performance. Overall, this work provides a systematic, quantitatively driven engineering framework for the design of durable, high-performance epoxy nanocomposites suitable for high-temperature and demanding industrial applications.

Abstract Research subject: This research aims to revive outdated Kevlar fabrics for reuse in the manufacturing of polymer-based composite parts. As a polymer fiber with high tensile strength and significant resistance to impact and heat, Kevlar is used in various industries, including automotive, aerospace, and protective equipment manufacturing. This type of reinforcement alone does not give a good bond with polymer resins, and to create a strong bond, a conciliator (sizing agent) is used, which has a useful life. The physical and mechanical properties change over time due to environmental influences such as humidity, ultra-violet rays, and high temperature.
Research approach: In this research, among the thermal, mechanical, chemical, plasma, nanoparticles, and layering methods, the chemical method was chosen to revive outdated Kevlar fabrics. For this purpose, at first, three waste fabric samples were selected and finally, the tensile properties of regenerated and non-regenerated fabrics were compared according to the ASTM D638 standard tensile test.
Main results: The results showed that the chemically regenerated fabric had about 11.3% more tensile strength than non-regenerated fabrics, and the chemical regeneration process positively improved the mechanical properties of old Kevlar fibers. This achievement paves the way for the reutilization of aged fibers in advanced structures. This shows that the chemical regeneration process not only increases the mechanical strength of materials, but can also positively affect their durability and stability against environmental factors. In addition, this research provides an economic and ecological method for reviving old fibers, providing a basis for reducing industrial waste and reusing polymer materials.

Abstract Research subject: Poly (vinyl chloride) (PVC) is non-biodegradable, and the widespread use of conventional plasticizers, particularly phthalates, in its formulation poses significant risks to human health and the environment. In this research, various blends of PVC and poly (lactic acid) (PLA) with different ratios were prepared in an internal mixer. The effect of PLA content, as well as the influence of various plasticizers including dioctyl phthalate (DOP), dioctyl adipate (DOA), epoxidized soybean oil (ESO), and chlorinated paraffin wax, on the mechanical and biodegradability properties was investigated. Furthermore, the role of a compatibilizer in improving the distribution of the PLA phase and increasing the compatibility between the polymers was evaluated.
Research approach: Tensile testing and dynamic mechanical analysis (DMTA) were performed to study the mechanical behavior. Scanning electron microscopy (SEM) imaging was used to examine the morphology and the distribution of the PLA phase. In addition, a biodegradability test was carried out to analyze the degradation behavior of samples in the environment.
Main results: The results indicated that the PVC/PLA(90/10)-DOP blend exhibited a suitable distribution of the PLA phase within the PVC matrix, whereas a poor distribution of PLA in PVC was observed in the PVC/PLA(80/20)-DOP blend. The addition of a compatibilizer to the PVC/PLA(80/20)-DOP sample led to increased uniformity in the PLA phase distribution and improved tensile strength. Samples with higher PLA content showed greater biodegradability behavior, suggesting the role of PLA as a degradability-enhancing agent. The comparison of different plasticizers indicated that several of the ones used in this research exhibit properties comparable to DOP and may be considered as effective substitutes for it. The findings suggest that the simultaneous use of PLA and appropriate plasticizers such as ESO, along with the application of a compatibilizer, is an effective method for producing PVC samples with enhanced mechanical and biodegradability properties.

Abstract This review article focuses on recent advancements in enhancing the mechanical, thermal, electrical, and corrosion-resistant properties of epoxy resin through the incorporation of surface-modified zinc oxide nanoparticles. The main objective of this review is to highlight the role of nanoparticle surface modification and weight fraction on the performance of epoxy nanocomposites and to provide a comprehensive overview of the findings reported in previous studies. In this review, scientific articles and experimental studies on epoxy nanocomposites containing zinc oxide nanoparticles were systematically analyzed. Selected studies were evaluated based on criteria such as the type of nanoparticle surface modification, dispersion and mixing methods, nanoparticle weight fraction, and the effects of these parameters on the mechanical and thermal properties of the epoxy matrix. Additionally, the findings related to hybrid nanocomposite structures and their synergistic effects were summarized. The review indicates that uniform dispersion of nanoparticles in the epoxy matrix improves interfacial adhesion, prevents stress concentration and crack propagation, and consequently enhances the overall strength and durability of the material. Most studies suggest that low nanoparticle loadings (0.25–1 wt.%) promote better dispersion and improved mechanical properties, whereas higher loadings may cause particle agglomeration and reduced performance. Surface modification of nanoparticles with silane or amine groups enhances compatibility with the polymer matrix, improves stress transfer, and increases thermal stability. Furthermore, recent studies show that hybrid nanocomposite structures create synergistic effects, simultaneously enhancing multiple performance characteristics. Overall, the incorporation of surface-modified nanoparticles into epoxy resin demonstrates significant potential for developing advanced materials in electronics, photonics, marine, medical, and aerospace applications.

Abstract Abstract
Research subject: Due to the drought and lack of water resources, many efforts have been made to store water properly recently. Using of multilayer polyethylene tanks is an efficient measure in order to solve this problem and it has received considerable attention. Proper manufacturing conditions will greatly improve the strength of these tanks and their applications.
Research approach: In this study, the effect of cooling process on the final properties of polyethylene tanks prepared by rotational molding method is investigated. Three different cooling methods comprised of cooling with water, cooling by air, and quiescent cooling is selected and their mechanical and thermal properties were investigated.
Main results: The results of the tensile test show that as the tank is cooled faster, the elongation at break will be higher. It is also demonstrated that the air cooling method results in the lower elongation at break. The results of the thermal properties show that higher cooling rate creates thicker crystals in the fragment which requires higher energy to overcome these thick crystals. According to the results of the thermal properties and using the softening temperature test it is found that by increasing the cooling rate, the softening temperature will be increased as well which will improve the application of the tank in high temperature conditions. Melt flow rate and density tests are also performed to confirm the results of mechanical and thermal properties, respectively. Charpy impact test is performed at ambient temperature to confirm mechanical behavior induced by crystal structure. All in all, cooling by water performs better than other methods in terms of mechanical and thermal properties.

Abstract Research subject: Increasing plastic wastes of the packaging industry and concerns about their environmental problems, have attracted many researchers to use biopolymers. Therefore, the preparation of cheap biodegradable films with desirable properties for using in the packaging industry can be an attractive challenge.
Research approach: In this study, poly (lactic acid) (PLA) based ternary blends were prepared by experimental design (mixture method). For this purpose, thermoplastic starch (TPS) was first prepared using 28 wt% sorbitol and 14 wt% glycerol. Then, PLA / PCL (poly (caprolactone), PCL) / TPS ternary blends at different concentrations were prepared using the melt mixing method. Morphological, physical (tensile, water vapor permeability), biodegradability, and rheological tests were also carried out. Finally, the optimum sample was determined using Minitab software.
Main results: Scanning electron microscope (SEM) images revealed incompatibility and phase separation in the blends. Moreover, with increasing PCL and TPS contents, flexibility enhanced due to the plasticization effect of PCL and mechanical properties declined, respectively. The permeability test results showed that the samples containing less TPS due to its hydrophilic nature and more PCL leads to increase the crystallinity of the matrix, had lower water vapor permeability. The effect of TPS on the biodegradability test was also well established. In this way, the sample containing 35 wt% TPS loses about 50% of its weight within 14 weeks. Finally, the sample with 50/25/25 (PLA / PCL / TPS) composition was selected as the optimum sample by Minitab software. The results showed that the formulated films in this study have the potential to be used in biodegradable packaging materials with good mechanical and barrier properties.

Abstract The aim of this project is the design and optimization of the formulation of epoxy adhesives for bonding metal to composite parts . This joints are most widely used in the aerospace industry to reduce stress concentration at a point. Joints for single edge joining include stainless steel metal with commercial code 316L and composite epoxy resin / carbon fiber. In this study, the effect of three types of additives: filler (alumina micro-particles), nylon 6.6 and phenolic resin (type of resin) on the mechanical and thermal properties of epoxy adhesive have been investigated. Tensile test results showed that increasing alumina fillers increases the tensile strength and overlap shear adhesive samples, respectively, in single lap joint dumbbells and elderly. The test showed that increasing the amount of nylon 6.6 When is slightly higher due to a sharp drop in tensile strength and overlap shear, respectively, in both cases is dog bone and single lap joint adhesives. This limit depends on the capacity epoxy ring to absorb amide hydrogens. The test for thermal properties (TGA) showed that increasing the amount of phenolic thermal stability is improved. High-temperature tensile test of appropriateness is also increasing impact of phenolic resin. Finally, the adhesive properties built with the similar adhesive (UHU) were compared. Results showed superiority in single lap joint metal to composite adhesive is made in the study.

Abstract Nowadays, investigating and researching on energetic polymers in order to increase mechanical, thermodynamic, and detonational properties of them have been highly regarded. One of these energetic polymers is GAP. In this paper, molecular dynamics simulation has been used to compare the properties of GAP and GTP energetic polymers. GTP, in principle is the modified form of GAP, in which functional group of triazolium methyl nitrate has been added instead of azide. The mechanical properties of GAP is a challenging topic in the field of energetic materials. Due to the attributes of the 3 azoliom methyl nitrate ring, the mechanical and thermodynamic properties of GTP are expected to be higher than GAP. The results obtained by molecular dynamics simulation showed that GTP is a stable material and its mechanical properties such as Young, and shear modulus compared to GTP have been decreased 27% and 32% respectively, and bulk modulus, Poisson coefficient, and K/G ratio compared to GTPhave been increased 17%, 42%, and 71% respectively. It was also found that the detonation speed, detonation pressure, and oxygen balance of energetic polymer compared to GAP, have been increased 5%, 14%, and 21% respectively. As a result, usage of GTP will increase as a modified GAP material in applications such as clean and chlorine-free propellants for the solid propellant rockets and also safety systems of automobiles.