Iranian Polymer Journal最新文献

Hydrogels are known as multifunctional materials that have been incorporated into fertilizers to improve crop yields, besides soil structure, and reduce water usage. Hydrogel-based controlled-release fertilizers (CRFs) have water retention and controlled-release properties simultaneously. They can reduce soil erosion, fertilizer waste, and nutrient loss compared to conventional fertilizers. Hydrogels also act as soil conditioners, leading to an increase in the porosity of soil and better air and water circulation. Regarding the great performance of hydrogel CRF as a sustainable solution for modern agriculture, some aspects of it, including definitions, various types (synthetic, natural, and semi-synthetic), properties, synthesis and preparation methods (matrix and coated), release mechanisms, economic factors, and their effect on plant growth, are reviewed in this essay. In general, modified natural hydrogel CRFs, as an environmentally friendly method, have shown good results in biodegradability, biocompatibility, affordability, and improving plant growth. However, various techniques, combinations, and additives such as biochar, nano clays, and/or synthetic hydrogels can be examined to reach better results and yields in the future. In conclusion, this essay reviews and compares various types of hydrogel-based CRFs from diverse aspects to encourage researchers to develop sustainable alternatives for future agriculture using natural resources.

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In the field of prosthodontics, in addition to meeting basic mechanical and biocompatibility requirements, ensuring the color of digital light-processing (DLP) denture base matches with the color of the oral mucosa and denture is imperative. Resins of different shades may lead to complex optical effects during the DLP printing process and then significantly affect the final product quality. Therefore, this study investigates the effect of resins with different red shades (G0-G5) on the DLP-printed specimens. We analyzed the L*, a*, and b* data for different shades, determined the degree of conversion using Fourier-transform infrared spectroscopy, conducted three-point bending tests to obtain the flexural strength and elastic modulus, performed Vickers hardness tests, and conducted hydrophilicity tests on the sample surfaces. Cell toxicity was also tested using L929 cells. The results indicated that shade variation significantly affected the degree of conversion, flexural strength, elastic modulus, Vickers hardness values, and cell toxicity across the different groups (p < 0.001). In the personalized customization of oral restoration, how to achieve a balance between various performance factors still needs to be solved, such as aesthetics, mechanics and biocompatibility. These discoveries not only provide a scientific basis for the application of DLP technology in the manufacturing of denture base resins but also offer valuable insights for the field of aesthetic prosthodontics.

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Enzymatic nanomotors have garnered significant attention as promising candidates for biocompatible propulsion mechanisms and for studying kinetic parameters during enzymatic degradation. Environmental pH has a notable impact on nanomotor performance, particularly in applications that replicate the acidic conditions found in cancer cells. Additionally, understanding how these motors can regulate their speed in response to changing pH levels is crucial for assessing their operational stability. In this study, Fe₃O₄ nanoparticles were synthesized and asymmetrically functionalized with hydrophobic β-amino ester (BAE) and hydrophilic dialdehyde starch (DAS) to create Janus-type nanoparticles. Structural characterization was conducted using ¹H NMR and ¹³C NMR spectroscopy for BAE and XRD and DSC for DAS, while further analysis was conducted using TGA, selective staining to differentiate hydrophobic and hydrophilic regions, SEM, FTIR, DLS, and zeta potential measurements. The motor characteristics of these Janus nanoparticles were evaluated in the presence of the CALB enzyme under neutral and acidic conditions. Velocity and diffusion analyses revealed a significant decrease in propulsion efficiency at lower pH, attributed to enzyme deactivation. Notably, these nanomotors demonstrated the ability to adjust their speed in response to pH changes, and their performance was reversible; restoring neutral pH led to the recovery of motor velocity while maintaining structural stability. The investigation of pH-triggered curcumin release, along with these findings, indicates the promising potential of enzyme-powered Janus nanomotors for precise control in biologically relevant environments, particularly in targeted drug delivery applications.

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This study investigates the crashworthiness performance and deformation behavior of 3D-printed square polylactic acid (PLA) non-prismatic structures with cutouts. The analysis focuses on four key design parameters: the half conical angle (0^o, 5^o, 10^o, and 15°), the diameter of the cutout (4, 8, 12, and 16 mm), the number of cutouts (1, 2, 3, and 4), and the location of the cutouts (20, 30, 40, and 50 mm). The printed structures were subjected to quasi-static axial compression loading to assess their crashing performance. Throughout the testing, both the crash load and energy absorption responses were meticulously recorded as a function of displacement. In addition to these measurements, the failure modes of the structures were thoroughly analyzed to identify the mechanisms driving deformation and fracture. The crashworthiness of the structures was evaluated using several key performance indicators, including the initial peak crash load(::left({text{F}}_{text{i}text{p}}right)), total absorbed energy (U), mean crash load ((:{text{F}}_{text{m}})), specific energy absorption (SEA), and crashing force efficiency (CFE). To determine the optimal combination of design parameters, the complex proportional assessment (COPRAS) method was employed. The findings revealed that the A15/D8/N2/L30 configuration, characterized by a half conical angle of 15°, a cutout diameter of 8 mm, two strategically placed cutouts, and a cutout location positioned 30 mm from the upper edge of the tube, exhibited the highest overall crashworthiness performance among the tested designs.

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Concerns over toxic elements in water have led to a focus on effective removal methods, aligning sustainable and effective solutions. This study introduces polysaccharide-based hydrogels (PSH) without and with Chocolate clay (PSH-C) for the removal of copper (Cu²⁺) from simulated effluent. Characterization using Zeta potential, FTIR, TG/DTG and SEM–EDX revealed improved properties in PSH-C. Cu²⁺ removal experiments investigated the impact of contact time and initial contaminant concentration. Results showed that PSH-C exhibited an enhanced porous morphology and thermal stability compared to PSH. The incorporation of clay provided more functional groups, thereby improving Cu²⁺ removal through electrostatic interactions. From the kinetic study, the insertion of Chocolate clay reduced the removal time for 20 min. The pseudo-first-order and pseudo-second-order models effectively represented the kinetics data.The isothermal equilibrium revealed that the Langmuir model analysis is a better fit with a maximum adsorption capacity of 221 mg g⁻¹. Key adsorption mechanisms were identified as electrostatic interaction, active site availability, and complexation. EDS analysis confirmed successful Cu²⁺ ion adsorption on both materials, suggesting a potential application in water treatment for heavy metals. This study introduces a modified hydrogel adsorbent that combines starch and Chocolate clay, offering a promising and sustainable solution for water treatment.

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Electromechanical performance of nanocomposites refers to the study of their electrical behavior in the presence of external mechanical effects. Understanding and controlling the electromechanical behavior of nanocomposites are essential for the development of advanced nanomaterials with improved properties and functionality. In thecurrent research, we introduced the electromechanical performance of MXene-polyamide nanocomposite using amolecular dynamics (MD) approach. For this, our computational study consists of two main phases. First, the thermodynamic equilibrium of the modeled sample is reported by calculating the temperature and total energy.Our results at this stage showed the physical stability of the modeled nanocomposite at an initial temperature of 300 K. Numerically, the total energy converged to 32.77 kcal/mol after 10 ns. This behavior arises from the stabilization of the average oscillation amplitude of the atoms and indicated the possibility of applying the designed structure in real and experimental cases. In the next step, external force was applied to mechanically expand the balanced MXene-polyamide nanostructure.MD outputs predicted the promising mechanical strength against this external factor. Numerically, theYoung’s modulus and ultimate strength ofthe sample converged to 2.31 and 317.79 N/mm², respectively. Furthermore, our results show that the electric current generated inside the sample is well defined and the current density reaches 0.16 e/fs.nm² after 10 ns.

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With the rapid increase in e-waste, the utilization of the nonmetallic fractions (NMFs) of printed circuit boards (PCBs) has become a focal point for addressing environmental problems and resource loss. Given that the main component of NMFs is glass fiber (GF), and since glass fiber is often used to enhance the mechanical properties of polypropylene (PP), NMF is expected to serve as a filler to improve the mechanical properties of PP. In this work, a melt-blending technique was employed to compound NMF with PP. The effects of compatibilizer type and content on the properties of PP were investigated. The results showed that the addition of NMF significantly reduced the mechanical properties of PP in the absence of a compatibilizer. With the addition of maleic anhydride grafted PP as compatibilizer, the tensile strength of PP reached 59 MPa, which was 78.8% higher than that of the PP/NMF composites without compatibilizer, while the flexural modulus reached 3600 MPa. SEM analysis confirmed that compatibilizer enhanced the interfacial bonding between PP and NMF where effectively reduced phase separation. Additionally, incorporation of NMF improved thermal stability of the composites, whose maximum decomposition temperature (T_dmax) increased by 8 °C. Thus, this work provided a feasible pathway for the high-value recycling of NMF and established a foundation for developing low-cost, high-performance, eco-friendly PP/NMF composites.

This study presents the synthesis and characterization of a novel pH-responsive hydrogel nanocomposite based on κ-carrageenan-g-poly(crotonic acid-co-sodium 4-vinylbenzenesulfonate) [κC-g-(CA-co-VBS)] reinforced with TiO₂ nanoparticles. κ-Carrageenan, a hydrophilic and biodegradable polysaccharide, was chemically modified through graft copolymerization with CA and VBS monomers, using potassium persulfate (KPS) as the initiator and N,N′-methylene bisacrylamide (MBA) as the crosslinker. The incorporation of TiO₂ enhanced the hydrogel’s swelling capacity (up to 3700%) and pH sensitivity. Structural and morphological analyses (FTIR, XRD, FE-SEM/EDX, HRTEM, BET) confirmed successful grafting and TiO₂ integration. The nanocomposite was evaluated as an adsorbent for Orange G dye, achieving a maximum adsorption efficiency of 677.4 mg/g and removal efficiency of 90.3% under optimal conditions (pH 7, 600 mg/L, 60 min). Adsorption followed the Freundlich isotherm model and pseudo-second-order kinetics, indicating multilayer chemisorption. Thermodynamic parameters suggested that the adsorption of OG dye onto the hydrogel composite was spontaneous (ΔG < 0), and endothermic (ΔH > 0). The hydrogel retained 82.7% efficiency after six regeneration cycles, demonstrating excellent stability and reusability. The novelty of this work lies in the incorporation of TiO₂ nanoparticles into a κ-carrageenan-based hydrogel matrix, which significantly enhances swelling capacity, adsorption efficiency, and reusability compared to conventional hydrogels, thereby offering an innovative and sustainable approach for dye-contaminated wastewater treatment.

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Polyimides (PI) composites are well-known for their use in microcircuits and offer excellent thermal stability and improved dielectric properties. However, they also present challenges, including uneven filler dispersion, a moderate fiber-polymer matrix interface, and process complexity. The research intends to overcome the above challenges and enhance the microstructural, dielectric, mechanical and thermal properties of polyimide composite samples composed of 0, 10, 20, and 30 percentages by weight of chopped carbon nanotubes (CNT) through the hot compression mould technique, with 3% (by wt) epoxy coupling agent is used to strengthen the interface between the fiber. The effect of CNT and coupling agents on microstructural and interface qualities is evaluated by transmission electron microscopy (TEM). With the excellence of the coupling agent and action of hot compression, the CNT fibers are widely dispersed and adhered to the PI matrix, which facilitates dielectric, mechanical, and thermal properties. The investigation result shows that the PI composite composed with 30% (by wt) CNT with 3% (by wt) epoxy coupling agent found to have improved microwave absorption of 17.20 GHz, a high dielectric constant of 5.2, and superior tensile and flexural strength behavior of 188 and 148 MPa, which are 70%, 62.5%, 50% and 85% superior to monolithic PI. In addition, the PI/30% (by wt) CNT composite demonstrates improved thermal stability with a reduced mass loss of 57%, which is 49% lower than that of monolithic PI. These combined enhancements make the PI/30% (by wt) CNT composite a promising candidate for microcircuit substrate applications.

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The COVID-19 pandemic has left a lasting environmental footprint, especially through the surge of single-use biomedical plastics such as disposable facemasks and nitrile gloves. Their improper disposal has created a new source of non-biodegradable waste, which fragments into microplastics and poses ecological and health hazards. This study establishes a sustainable recycling pathway by extracting polypropylene (PP) from discarded facemasks and nitrile butadiene rubber (NBR) from used gloves, and reinforcing them with Cloisite nanoclay to develop toughened nanocomposites. The incorporation of nanoclay significantly enhanced tensile strength, hardness, dielectric performance, and thermal stability, with optimum properties achieved at a 3.5% (by wt) loading. Structural and morphological investigations using FTIR, TGA, SEM, and AFM confirmed improved interfacial adhesion, uniform filler dispersion, and suppression of phase separation at this level. Beyond 3.5% (by wt) nanoclay, agglomeration effects reduced mechanical efficiency. The multifunctional nature of these composites makes them attractive for tribological applications, electrical insulation, and lightweight structural uses. Additionally, their compatibility with extrusion-based additive manufacturing provides scalability and adaptability to 3D printing of durable, customized components. This dual achievement of biomedical waste valorization and high-performance material development demonstrates a cleaner production strategy aligned with circular economy principles. Overall, the work not only offers a feasible solution to pandemic-related waste management but also establishes a pathway for developing sustainable, high-value nanocomposites with industrial relevance.

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