Iranian Polymer Journal最新文献

Hemp seed oil and epoxy resin were made into a novel bio-based epoxy system without chemical treatment with this study. Vegetable oil is added to the resin at five different rates (10%-50%), samples were produced with cotton, jute/flax, and hemp fabric as reinforcement for this bio resin. The vacuum-assisted resin transfer molding process was used. The samples were tested for tensile strength, impact strength, microhardness, and ignition loss. Moreover, fiber matrix bonding was observed using morphological analysis. Tensile test outcomes indicated 10% oil added cotton and jute/flax fabric samples had better tensile strength than the pure epoxy sample by 3.94% and 14.42%, respectively. In the impact test, adding 40% oil to jute/flax and hemp fabric enabled the samples to absorb an average of 1.73–4.19 times more energy. The ignition lost results reflect the addition of oil to epoxy resin reduces the ignition resistance by 1.04–1.11 times. The incorporation of 10% oil enhances tensile strength, while the addition of 40% oil results in the attainment of maximum impact resistance values. In the hardness test, an increase of approximately 13%–29% was observed in all fabric types with a 10% oil addition; however, an increase in friction loss was recorded as the oil content increased. These biocomposites can be regarded as a sustainable alternative in areas requiring energy absorption and flexibility and with their significant elastic behavior, they have the possibility of being used in areas such as automotive interior trim parts, building materials and aerospace.

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Many studies have explored using natural fibers from biomass as reinforcement in thermoplastics. However, a key challenge in developing these composites is achieving effective interfacial adherence between the hydrophilic natural fibers and hydrophobic polymer matrix. Additionally, excessive or insufficient amounts of fiber and compatibilizer can lead to composite failure due to poor dispersion, inadequate interfacial bonding, or fiber agglomeration. In this work, banana fibers at 10, 20, and 30 wt% were incorporated into high-density polyethylene (HDPE) along with 1, 3, 5, and 7 wt% of maleic-anhydride polyethylene (MAPE) as a compatibilizer. The composites were characterized for microstructure, tensile properties, and degree of crystallinity using SEM, FTIR, DSC, and tensile testing. Compared to unfilled HDPE, the addition of banana fiber significantly increased tensile modulus despite limited interfacial bonding. Tensile strength further improved with the addition of 3, 5, and 7 wt% of MAPE to composites containing 30 wt% fibers, suggesting enhanced fiber-matrix adhesion. This was supported by weak FTIR absorption peaks at 1715 and 1740 cm^− 1 attributed to esterification between hydroxyl groups and MAPE. Elongation-at-break (EAB), however, decreased with higher fiber content due to the fibers’ rigidity, though MAPE slightly mitigated this effect by improving stress transfer. Differential scanning calorimetry (DSC) indicated that all composites exhibited elevated crystallinity, indicating the formation of additional crystalline regions within the matrix due to fiber inclusion. This effect was further enhanced by MAPE, which improved molecular organization.

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This study presents a novel approach to reinforcing concrete pipelines using 3D-printed auxetic tubular structures (ATS). These structures, featuring V-shaped reentrant unit cells (VRU), were fabricated from ABS resin via digital light processing (DLP) 3D printing. By systematically varying the wall thickness (0.5 mm, 1.0 mm, 1.5 mm) and reentrant angle (120°, 140°, 160°), the research evaluated their impact on Poisson’s ratio, stiffness, energy absorption, and stress distribution. All configurations exhibited negative Poisson’s ratios, with the most pronounced auxetic behavior observed at 0.5 mm thickness and 120° angle, achieving a Poisson’s ratio of -0.742. Stiffness increased significantly with both wall thickness and reentrant angle, reaching up to 120 N/mm at 1.5 mm thickness and 160° angle. Energy absorption also scaled with thickness, with the 1.5 mm thick structures at 140° angle absorbing up to 639 mJ. The configuration with 1.5 mm thickness and 140° angle was identified as optimal, offering a balance of high energy absorption (639 mJ), moderate stiffness, and uniform stress distribution. Finite element analysis (FEA) validated the experimental findings, with discrepancies below 5%, confirming the potential of these novel 3D-printed ATS to enhance the structural integrity of concrete pipelines under dynamic loads.

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Wound healing represents a highly coordinated biological process in which damaged tissue undergoes repair and regeneration. In the present study, Hibiscus rosa-sinensis-pectin hydrogel films (HRS-PHF) were evaluated for their wound healing potential using a partial-thickness burn model in male Sprague Dawley rats. Three concentrations of HRS-PHF and a pectin-only hydrogel film (PHF) were prepared through solvent evaporation and characterized in detail. The films were examined for their physicochemical and structural properties using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD), along with measurements of thickness, pH, moisture content, contact angle, and swelling ratio. Antimicrobial activity was tested against Pseudomonas aeruginosa and Staphylococcus aureus, while anti-inflammatory effects were assessed using the bovine serum albumin (BSA) protein denaturation assay. Wound progression was evaluated macroscopically on days 0, 2, 7, 14, and 21, followed by histological confirmation. All HRS-PHF-treated groups exhibited accelerated wound closure compared to PHF and control groups, accompanied by enhanced re-epithelialization and greater collagen deposition by day 14 (ANOVA; p < 0.05). Improved hydrophilicity was observed in HRS-PHF-1, and XRD results confirmed the films’ amorphous characteristics. HRS-PHF-2 and HRS-PHF-3 showed notable antibacterial activity, with HRS-PHF-3 demonstrating anti-inflammatory activity comparable to diclofenac sodium (ANOVA; p > 0.05). Collectively, these findings indicate that HRS-PHF possesses desirable multifunctional properties suitable for advanced wound dressing applications.

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This study investigates the effects of simple blending and three distinct curing systems: sulfur, peroxide, and phenolic, on the properties of epoxidized natural rubber (ENR)/thermoplastic starch (TPS) blends filled with 20 phr bio-filler, rice husk ash (RHA). It was found that the phenolic-cured blend exhibited the highest tensile strength and Shore A hardness, attributed to rigid methylene bridges with Chroman ring structures and strong interfacial hydrogen bonding with RHA, TPS and ENR. Despite its highest torque difference or crosslink density, the sulfur-cured blend showed only moderate mechanical properties due to limited compatibility among the ingredients. The peroxide-cured thermoplastic vulcanizate (TPV) showed the lowest tensile strength but the highest elongation (~ 600%), reflecting its low crosslink density. Thermo-mechanical analysis indicated superior thermal stability in the phenolic system (T₉₀ ~213.2 °C), while the simple blend showed rapid softening. SEM revealed uniform morphology of vulcanized ENR domains dispersed TPS matrix in the phenolic-cured blend, whereas the simple and peroxide blends exhibited coarse co-continuous phase structure. In addition, the simple blend and peroxide systems showed higher water uptake and biodegradability, while the phenolic system had minimal degradation. These findings emphasize the trade-offs between performance and environmental degradability, guiding the selection of curing systems for sustainable applications such as packaging and agricultural containers.

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Recent advancements in novel biomaterials have garnered significant attention, particularly for biomedical applications. Over the past few decades, a variety of elastomeric bio-nanocomposites with exceptional performance have been developed, combining elastomers and bio-based nanofillers. This research focuses on the modification of nanocellulose (NC) by Cassia fistula seed gum (CFG), a natural polysaccharide with excellent antibacterial properties, to enhance interface bonding and improve the properties of elastomeric composites. Scanning electron microscopy (SEM) revealed a fibrous structure of CFG-modified NC (CFGNC) with an average fibre diameter of 80 nm. Successful modification of NC was confirmed through elemental analysis (EDX), infrared spectroscopy (FTIR) and atomic force microscopy (AFM), while the crystallinity of NC with CFG was revealed through X-ray diffractogram. The CFGNC was incorporated into deproteinized natural rubber (NR) latex to prepare elastomeric bio-nanocomposites. The NR/CFGNC-2 composite exhibited a 35% increase in tensile strength and a 65% enhancement in modulus compared to NR/CFGNC-0. Thermogravimetric analysis (TGA) results showed enhanced thermal stability, with improvements of 21 °C and 10 °C for CFGNC and NR/CFGNC-2 composite, respectively. Antibacterial assays confirmed effective inhibition against common bacterial pathogens, validating the bioactive nature of CFGNC. The utilization of CFG as an NC modifier represents a novel and sustainable biopolymer functionalization strategy, enhancing dispersion, interfacial compatibility, and network formation within the NR matrix. This synergistic integration of renewable nanocellulose and natural gum offers a promising route to develop multifunctional, high-performance, and eco-friendly elastomeric composites tailored for diverse biomedical and sustainable material applications.

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Polymer composites are often employed in many outdoor applications which expose it to Ultraviolet (UV) radiation. UV exposure to polymer composite resulted in the change of physical, chemical, and mechanical characteristics. Recently, polymers like thermoplastic polyurethane (TPU) have been reinforced with nanofiller like cellulose nanocrystal (CNC) and successfully improve its mechanical properties. However, the effect of UV resistance has not yet been studied. In this work, 1 wt% of CNC hydrolyzed by phosphoric acid was used as reinforcing filler. CNC/TPU nanocomposite films were fabricated through melt extrusion followed by compression molding and subsequently subjected to artificial UV irradiation for 3, 6, 12, and 72 h. Mechanical testing revealed that after 72 h of UV exposure, the tensile strength of neat TPU decreased by 45%, while CNC-reinforced TPU showed a lower reduction of 34%, representing an overall improvement in UV resistance of approximately 24%. Fourier transform infrared (FTIR) spectroscopy indicated that CNC incorporation mitigated photo-oxidative chain scission by preserving hydrogen-bonded N–H and C=O groups, while differential ccanning calorimetry (DSC) analysis showed increased glass transition temperature (T_g) and enthalpy, suggesting CNC-induced structural confinement and UV-triggered crosslinking stabilization. The results confirm that phosphoric-acid-derived CNCs act as an effective reinforcing and UV-shielding nanofiller without compromising transparency, enhancing both mechanical retention and thermal stability under UV aging.

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Oily wastewater is produced throughout the petroleum extraction process, from drilling and oil production to collection and transportation. Such effluent comprises not only large amounts of free and emulsified oil, but also a variety of poisonous and hazardous compounds. When these compounds are released without appropriate treatment, contaminating drinking water sources via groundwater penetration, and causing irreparable damage to ecosystems and human health it is difficult to be reversed. With global petroleum demand rising and environmental standards tightening, the scientific and efficient treatment of such oily wastewater to achieve the dual objectives of ‘compliant discharge’ and ‘resource recovery’ has emerged as an urgent global challenge for both the petroleum industry and the environmental sectors worldwide. Separation of components in oily wastewater presents a pressing challenge, extending beyond mere oil-water separation to encompass the isolation of other harmful constituents. Developing an economical, environmentally sound, and highly efficient membrane remains a significant technical hurdle. This study presents a semi-interpenetrating polymer network (semi-IPN) hydrogel with oil-water separation functionality, fabricated from the renewable green resource alkanolamine (AL). Lignin was first modified using polyethyleneimine (PEI), followed by incorporation of semi-IPN polyvinyl alcohol (PVA) linear molecules, after adding SiO₂ nanoparticles, the resulting semi-IPN hydrogel exhibited remarkable superhydrophilicity (OCA = 156°) and strong chemical stability. This superhydrophilic behaviour was attributed to low surface energy and the roughness imparted by the SiO₂ nanoparticles. With a stable average efficiency of 99%, it overcomes the difficulty of attaining stable separation across various oil phases while retaining continuously high separation efficiency.

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The growing environmental and toxicological concerns associated with conventional crosslinkers have driven a transition toward sustainable alternatives in hydrogel fabrication. This review highlights recent advances in green crosslinking technologies, analyzing their mechanisms, performance, and industrial potential within the global crosslinking market, valued at USD 9.9 billion in 2023 and projected to reach USD 13.6 billion by 2028. Green crosslinkers are categorized into three classes: natural agents from renewable biological sources, synthetic green crosslinkers with enhanced biocompatibility, and biodegradable agents designed for controlled degradation. Mechanistic pathways include Schiff base chemistry, esterification, ionic and hydrogen-bond interactions, and enzymatic catalysis with transglutaminase or horseradish peroxidase. Performance data underscore their advantages. Genipin shows 5000–10,000-fold lower cytotoxicity than glutaraldehyde while offering higher thermal stability (268.45 °C vs. 251.67 °C). Life cycle analyses demonstrate 30–50% lower carbon footprints and 35% reduced cumulative energy demand in renewable feedstock systems. Tunable mechanical strengths (10–100 kPa) with pH-responsive swelling (100–500%) enhance versatility. Environmental applications report over 90% heavy metal removal within 30 min and regeneration over five cycles. Biodegradable agents achieve complete hydrolytic or enzymatic degradation in 7–14 days, easing end-of-life management. Yet, barriers remain: cost disparities ($1.5–500/kg), natural extract variability, scalability challenges, and stringent regulatory approvals under TSCA, REACH, and FDA. Emerging strategies-natural deep eutectic solvents (NADES), agricultural by-product utilization, and continuous-flow processing-offer 30–40% cost reduction and improved reproducibility. Future opportunities lie in dynamic covalent networks and upcycled waste resources, enabling sustainable, economically viable, and regulatory-compliant polymer manufacturing.

Herein, stretchable multifunctional superhydrophobic films with high robustness were fabricated using simple spraying approach. More specifically, a rigid polymer named poly(amide imide) (PAI) and an elastic polymer named thermoplastic polyurethane (TPU) were adopted to prepare stretchable substrate, which exhibited a tensile strength as high as 43 MPa and an elongation-at-break close to 240%. Encouragingly, the mechanical property of composite coating was nearly unchanged after spraying the modified silica (m-SiO₂) and multiwall carbon nanotubes (MWCNTs) on the substrate surface. Hierarchical pore structure with micro/nano size was constructed, which endowed the PAI-TPU/MWCNTs/m-SiO₂ composite films with excellent hydrophobicity, the water contact angle (CA) was as high as 154°, and the sliding angle (SA) was below 5°. More interestingly, intensive conductive network was formed, and thus the PAI-TPU/MWCNTs/m-SiO₂ composite coating showed good electrothermal property, the temperature increased by 26 °C at a safe voltage of 36 V even it was elongated by 40%. Also, due to the good optical absorption ability of MWCNTs, the PAI-TPU/MWCNTs/m-SiO₂ stretchable composite coating exhibited unique photothermal property, the equilibrium temperature increased from 16.5 to 123 °C when the intensity of optical power increased from 0.02 to 0.22 W/cm², correspondingly. More importantly, the PAI-TPU/MWCNTs/m-SiO₂ composite coating showed high robustness, the CA and SA were almost unchanged even if they were suffered from harsh treatments such as ultrasonic oscillation, sandpaper abrasion, hot-water jet impingement, UV irradiation, and immersion in strong acid or alkali solutions.

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