Iranian Polymer Journal最新文献

Growing demand for sustainable composites has driven the exploration of natural materials hybridization. In this study, limitedly explored, Abutilon Indicum fiber was considered as epoxy reinforcement along with hemp. To investigate the effective proportion of Abutilon Indicum fiber in the epoxy composite, the samples were fabricated with balanced (AIHE-1) and unbalanced (AIHE-2 and AIHE-3) proportions of hemp and Abutilon Indicum through the compression moulding process and are compared over the Abutilon Indicum only inducted epoxy composite (AIE). The FTIR confirms the functional groups were consistent irrespective of the proportions of the reinforcements, indicating the stable interfacial bonding. The average crystalline size of the AIHE-1 was found to be 31.5 nm by XRD analysis. The better fiber distribution and interfacial bonding was found through SEM analysis for the AIHE-1. By that, AIHE-1 depicts higher thermal stability up to 374 °C, better sound absorption coefficient (average) of 0.20, and low surface roughness (average) of 55 nm as compared to AIE and unbalanced reinforcement composites. The wear analysis shows that the AIHE-1 has least wear rate of 0.12 mm³/N.m at the load of 30 N with the sliding speed of 2.25 m/s. These results suggest the balanced hybridization of Abutilon Indicum and hemp was recommended to use in interior automotive components for offering better thermal, acoustical, and wear properties.

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Composites are materials with high specific strengths. These materials can be examined in terms of mechanical strength by experimental or finite element methods (FEM). It has been determined in the literature that various material models are used in modeling composite materials by finite element method. In order to model composite materials correctly by FEM, it is very important to determine the material model data (physical and non-physical parameters) correctly. However, there are limited studies in the literature on determining the physical and non-physical parameters used for Ls dyna software material models of materials. For this reason, the material model data of unidirectional glass/epoxy composite material in different temperature environments were determined by FEM (Ls dyna software and MAT 55/MAT 59 material models) in the study. Material model data were determined by comparing the experimental results of composite materials with the results obtained by the FEM. As a result of the study, both material model data were obtained and the effect of the thermal environment on the material model data was investigated. It was determined that the material model data also changed with the change of ambient temperatures. Moreover, it was determined that the MAT 59 material model gave better results.

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This study selected poly (1, 4-cyclohexanedimethanol isosorbide terephthalate-co-ethylene terephthalate), whose abbreviation is PCIC, as the matrix and mainly explored the influence of antioxidant types and addition amounts on the optical properties of PC_30%IC. Through comprehensive characterization methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and transmittance testing, the structure, morphology, thermal and optical properties of the synthesized composites were investigated. It was found that triphenyl phosphite (TPPi) had a better color protection effect on ISB. The performance of PC_30%IC with different TPPi addition ratios was studied. The results showed that TPPi itself did not participate in the reaction, so there were no obviously characteristic peaks in the infrared and nuclear magnetic resonance test results of the product. However, TPPi could appropriately increase the molecular weight of the copolymer, and the T_g and tensile properties of the copolymer also got a slight improvement. TGA curves showed that TPPi had little effect on the Td_5% of the copolymer, but its Td_max has been increased. Moreover, the addition of TPPi could inhibit the cross-linking reaction or carbonization which could aslo reduce the residual mass. More importantly, TPPi could prevent the occurrence of oxidation reactions by capturing free radicals and decomposing peroxides, thereby reducing the formation of chromophores. However, this effect was limited. When the addition amount of TPPi reached 0.005 of the total molar mass of the alcohol, phase separation occurred, which instead reduced the transmittance. When the content of TPPi was 0.003, the ultraviolet transmittance of the film was the best, reaching 90.94%, with a b* value of 1.25.

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A novel wound dressing is developed by incorporating cinnamon essential oil (CEO) into polyvinyl alcohol/chitosan (PVA/Cs) hybrid hydrogels to synergistically enhance antibacterial activity, controlled release, and wound healing properties. Hybrid hydrogels were fabricated using a freeze–thaw method with varying CEO concentrations (2–8% by wt). Characterization with Fourier-transform spectroscopy (FTIR) confirmed successful CEO incorporation and hydrogen bonding between PVA/Cs, while morphology analysis exhibited the incorporation of CEO into hybrid hydrogel increased the average pore size from 12 to 30 μm. Physically crosslinked PVA/Cs hydrogels had a significant water uptake capacity, ranging from 610% (w/w) to 911% (w/w), with swelling reduced over time by increasing the amount of CEO in the hybrid hydrogels. The hydrogels exhibited biphasic CEO release, with an initial burst (37% within 8 h) followed by sustained release (52% over 72 h), best described by the Higuchi model (R² > 0.99) and non-Fickian diffusion (n > 0.5). The hybrid hydrogels demonstrated no toxicity after incorporating CEO, with cell viability above 70%. It also demonstrated significantly higher efficacy and antibacterial activity against Escherichia coli than Staphylococcus aureus (p < 0.05). The CEO-loaded PVA/Cs hydrogels demonstrated optimal swelling, controlled release, and antibacterial properties, making them promising candidates for advanced wound dressings. The synergistic effects of CEO and the hydrogel matrix address key challenges in wound management, including infection control and sustained therapeutic delivery.

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Additive manufacturing (AM) of biodegradable composites incorporating triply periodic minimal surface (TPMS) structures presents significant opportunities for lightweight structural applications. However, their mechanical performance under different loading conditions remained insufficiently explored, limiting a comprehensive understanding of their overall potential. Therefore, this work aimed to experimentally evaluate the performance of gyroid structures made from polylactic acid (PLA) and carbon fibre-reinforced polylactic acid (PLA/CF) containing 15 wt% carbon fibre, fabricated via fused deposition modelling and subjected to quasi-static compression and tensile testing. The evaluation also included material characterizations techniques such as thermogravimetric analysis (TGA) and X-ray diffraction (XRD), which confirmed enhanced thermal stability and crystallinity in the composite. The experimental results demonstrated a 57% improvement in the ultimate tensile strength of the composite compared to pure PLA, which could be attributed to efficient stress transfer and crack deflection. Further deformation analysis under tension revealed a delayed fracture response in the composite, with fiber-matrix interactions mitigating crack propagation. These findings highlighted the potential of sustainable composites for lightweight applications, where the integration of biodegradable polymers with architected lattice structures opened opportunities for further development across broader applications. This approach directly aligned with sustainable development goals (SDGs) by improving resource efficiency and reducing environmental impacts, while maintaining high structural performance.

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This study explores the effects of sol-gel polyol, isocyanate, and kaolin composition on the composite polymer’s tensile strength and thermal properties. The sol-gel polyurethane composites (SPUCs) were formulated by optimization of various parameters using “response surface methodology” with Central Composite Design. Biodegradable polyurethane was synthesized using cardanol-based sol-gel polyol. RSM optimization indicates that the composition, consisting of sol-gel polyol, isocyanate, and kaolin in a 3:6.5:1.5 ratio, achieves a tensile strength of 3.1053 MPa. Validation through experimental testing shows a tensile strength of 3.1384 MPa, which closely matches the predicted value with the model. Cardanol-based sol-gel polyol was characterized using attenuated total reflectance-Fourier transform infrared spectroscopy. The SPUCs were characterized using thermogravimetric analysis, scanning electron microscope, and contact angle. Resultant SPUC coatings were applied to urea granules, and their nutrient-release behavior was examined by UV-visible spectroscopy, confirming the release performance. The integration of renewable cardanol chemistry with kaolin reinforcement and statistical optimization produced mechanically robust, thermally stable biodegradable coatings suitable for controlled-release fertilizer applications.

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This study investigates a novel carbon fiber reinforced polymer (CFRP) quasi-elliptical honeycomb sandwich structure, designed by a bio-inspired approach based on the microstructure of beetle elytra. Compared with conventional straight-walled honeycomb connections, the arc-shaped connections in this innovative design significantly reduce stress concentration under external loading, effectively suppressing local failure risks and enhancing overall structural performance. To overcome the limitations of secondary bonding typically used in traditional honeycomb manufacturing, this study developed specialized molds for the integrated fabrication of quasi-elliptical honeycomb cores using unidirectional CFRP epoxy prepreg through hot-press molding. Employing combined experimental and finite element simulation methods, the investigation systematically examined the failure mechanisms and bending behavior under three-point bending conditions, with a particular focus on the effects of relative density and face-sheet thickness. A parametric analysis was conducted to elucidate the influence of the unit cell dimensions on the structural performance. Key findings demonstrate that specimens with medium relative density achieve optimal specific bending stiffness, while increasing face-sheet thickness significantly enhances both specific peak load and energy absorption capacity. A comparative analysis with competing sandwich structures confirmed the exceptional bending characteristics of the proposed design, which maintained a competitive bending modulus and strength even at low density levels, thereby validating its outstanding bending resistance.

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In the context of this study, the synergy between Maghnite® organophilic clays (Mag-TBA and Mag-CTA) and graphene functionalized with epoxy groups (Gr) opens up new possibilities for improving the functional properties of biodegradable matrices based on poly (polylactic acid) (PLA) and poly(ε-caprolactone) (PCL), particularly in their PLA/PCL blends with a mass ratio of 70/30. This research aims to explore the composition of PLA/PCL polymer blends and their ternary and quaternary nanocomposites, using morphological characterization techniques such as transmission electron microscopy (TEM) and scanning electron microscopy, as well as thermal analysis, to evaluate their behavior and functional properties. Polymer nanocomposites with different PLA/PCL/Mag-Org/Gr ratios were developed using a sustainable and scalable manufacturing approach in the molten state. The synergistic optimization of Mag-Org/Gr reinforcements has significantly improved the rheological behavior of the PLA/PCL matrix, as shown by the results obtained for the loss modulus and storage modulus. This improvement confirms high co-reinforcement, attributable to improved dispersion, as confirmed by transmission and scanning electron microscopy PLA/PCL containing nanoparticle fillers showed a higher barrier. Optimal performance was achieved by combining hybrid compounds of organomontmorillonite and graphene, whose combination produced a synergistic effect. The PLA/PCL and its ternary and quaternary nanocomposites exhibit greatly improved thermal stability.

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In this paper, we work on the use of phytic acid as a new flame retardant hybrid coating agent with high alpha cellulose pulp obtained from Capparis Spinosa buds. It is combined with phytic acid to enhance the flame retardant properties of plant buds, being rich in nitrogen. Additionally, non-toxic cross-linking functional monomers poly(ethylene glycol) diacrylate, vinyl phosphonic acid, 3-(trimethoxysilyl) propyl methacrylate, ethylene glycol dimethacrylate and acrylamide are added to the produced solgel formulation, thus imparting a binary network structure to the hydrogel matrices. The characterization of flame retardant solgel films is carried out using Scanning Electron Microscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) analyses, and also Capparis Spinosa plant and phytic acid containing UV cured hybrid films are studied by Thermogravimetric Analysis (TGA). As the plant content in the hybrid films was increased, the second thermal decomposition temperatures of the films shifted to a higher temperature compared to the base formulation. The highest thermal stability and charring efficiency were observed in PTXPA films compared to the other films. The second best thermal stability was observed in the hybrid films containing 10% Capparis Spinosa. These studies show promising results for the development of sustainable, non-toxic flame retardant coatings, with the LOI value increasing by 28.9% compared to the base form, reaching 24.5. The combination of Capparis spinosa and phytic acid provides a bio-based alternative to conventional halogenated flame retardants, offering potential applications not only in textiles but also in paper products, packaging materials, and eco-friendly construction composites.

Adding pomegranate peel powder (PPP) to starch films provides antibacterial properties and improves the films’ physical properties. In this study, before incorporating the PPP into the film-forming solution, planetary ball milling of the PPP was applied to achieve a finer particle size and a narrower particle size distribution. The highest tensile strength (TS) value was achieved with the addition of 0.35% (w/w) of PPP, resulting in a ~ 29% increase compared to the PPP-free starch film. When 0.35% (w/w) of PPP was added to the starch film, the degree of swelling decreased from 165.59 ± 9.74% to 151.66 ± 7.33%. However, at higher PPP concentrations, there was an increase in swelling due to the agglomeration of PPP. Specifically, as the concentration of PPP in starch increased from 0.7% to 1.5%, the swelling degree showed an upward trend. PPP reinforcement results in a significant increase in the solubility of the starch film. The water solubility of the films increased from 18.25 ± 0.58% to 27.99 ± 0.79% with the increasing amount of PPP reinforcement in the starch film. Water vapor permeability of the pure starch film was 1.87 ± 0.51 × 10^–10 gm⁻¹ s⁻¹ Pa⁻¹ and rised to 2.02 ± 0.27 × 10^–10 gm⁻¹ s⁻¹ Pa⁻¹ with increasing amounts of PPP. The PPP reinforcement resulted in a notable increase in the contact angle of the starch film. The pure starch film revealed a contact angle of 20.40 ± 6.11°. However, when 0.35% PPP was added, the contact angle increased to 27.89 ± 1.46°. With further addition of PPP, up to 1.5%, the contact angle increased significantly to 48.47 ± 4.79°. The films exhibited a high antibacterial activity against Staphylococcus aureus.

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