Journal of Polymer Research最新文献

In this study, the effect of thermal and UV-ozone/ozone-induced oxidation on the electrical conductivity of poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate) (PEDOT:PSS) film was systematically studied by varying two dry oxidation mechanisms: annealing of PEDOT:PSS from 120 to 240 °C and UV-ozone/ozone exposures at different time intervals (i.e., 0 to 32 min). The comparative maximum electrical conductivity was achieved in the 200 to 240 °C annealing range, with conductivity showing a dynamic, complex dependence on temperature: initial reduction at lower temperatures, followed by a dramatic increase around 200 °C, and subsequent saturation at 220–240 °C. This behavior is attributed to the temperature’s influence on the organization and cross-linking/alignment of polymer chains. However, the high conductivity achieved at 240 °C significantly degraded within five days, contrasting with the more stable conductivity observed for films annealed at 150 °C and 200 °C. On the other hand, both UV–ozone and pure ozone treatments increased the surface energy and work function of the polymer; however, the rate of increase in surface energy was higher for UV–ozone, while the rate of increase in work function was higher for ozone-only exposure. Such changes in electronic and surface properties are likely driven by UV/ozone-induced oxidation and the resulting cross-linking within the material. The findings offer new insights into the oxidation-driven modifications of PEDOT:PSS, providing strategies to precisely tailor its electronic and surface properties for enhanced optoelectronic device performance.

Graphical Abstract

Freezing-thawing (F-T) cycles approach was applied for loading caffeic acid to physically-crosslinked hydrogel membranes composed of PVA/chitosan/caffeic acid (PVA-CS-CA). Three F-T cycles were carried out to guarantee the entanglement of PVA-CS-CA chains. Several instrumental characterizations were used to confirm and characterize the entanglements of polymeric chains. Physicochemical parameters of PVA-CS-CA membrane including swelling ratio (%), mechanical properties, gel fraction (GF%), hydrolytic degradation (%), and thermal stability, were thoroughly examined. Findings demonstrated that GF% gradually decreased with increasing CS content in the membrane composition, while mechanical characteristics, swelling ratio (%), and hydrolysis of the crosslinked materials improved. Furthermore, MTT assay and bacterial inhibition of growth percentage method were utilized to assess the antimicrobial characteristics towards Staphylococcus aureus and E. coli, respectively, and the cell viability test utilizing HFB-4 cell line. Interestingly, all of hydrogels investigated demonstrated noteworthy cell survival percentages with various incubation durations and membrane concentrates. The findings supported the hypothesis that hydrogel films might be used as biomaterials to promote quick wound healing or as antibacterial dressings in a professional setting.

The multifunctional polymer-based hybrid microgel combined with metal nanoparticles have effective catalytic approach to degrade the contaminants due to the external stimuli response as well as drug delivery agent. In this research work, the bimetallic hybrid microgel which is poly(N-Isopropylacrylamide) integrated with Ag and Fe₂O₃ nanoparticles (NPs) was prepared by the in-situ method. The AgNPs were prepared by the chemical reduction method using silver nitrate and trisodium citate while the iron oxide NPs were prepared by using the co-precipitation method. Then the prepared iron oxide and silver NPs were integrated in the prepared poly(N-Isopropylacrylamide) hybrid microgel by using in-situ method. The prepared microgels were characterized by using UV-Visible spectrophotometer, Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Zeta Potential analysis and X-ray Photoelectron Spectroscopy (XPS). The cytotoxicity assay of the prepared microgel was analyzed against human colon cancer cells (SW480) and normal cell line NIH/3T3. The molecular docking was also performed for the cytotoxicity using Topoisomerase IIβ (4g0u) and EGFR TKD (1m17) proteins. The anticancer drug cisplatin was loaded on the microgel and its controlled release was analyzed in buffer solution of pH 7.4 at 32 °C and 37 °C by using UV-Visible spectrophotometer and Raman spectroscopy. The chemometric tool, Partial Least Squares Regression (PLSR) tool was employed on Raman spectral data for the quantitative analysis of the released drug at 37 °C temperature. The Flory-Huggins analysis (χ = 0.041–0.134) confirmed high thermodynamic compatibility of PNIPAM with Ag and Fe₂O₃ nanofillers, ensuring structural stability and sustained LCST response. The UV-Visible spectrophotometer was used to analyze its catalytic activity and comparison efficiencies between bimetallic and single-metal microgels by the degradation of the methylene blue (MB) dye and how the prepared catalyst affected the apparent rate constant (kapp) of MB dye. The prepared microgels integrated NPs showed remarkable multifunctional applications as controlled cisplatin release and degraded the methylene blue dye effectively.

The fused deposition modelling (FDM) parameters for ABS components were optimised using a combined experimental and computational approach. A central composite design was used to fabricate 31 ASTM D638 Type IV tensile specimens by adjusting layer height, infill density, infill pattern, and printing speed. Elongation at failure varied from 5.1% to 13.1%, and tensile strength ranged from 21.6 to 26.9 MPa. Layer height was identified as the primary driver of stiffness (linear coefficient = 170.4, p < 0.001) and infill density as the primary factor governing strength (coefficient = 2.280, p < 0.001) after Response Surface Methodology (RSM) generated models with R² values above 0.79. Elongation showed a U-shaped relationship with layer thickness (R² = 0.876), suggesting different ductility and strength regimes. Three-dimensional surface plots showed that the best conditions were for coarser layers (0.25–0.30 mm) with moderate infill (60–75%) for improved ductility and layer heights of 0.10–0.15 mm with high infill (85–90%) and a cubic pattern for maximum stiffness and strength. According to a multi-criteria analysis using the Order of Preference by Similarity to Ideal Solution (TOPSIS), the configuration with 0.15 mm layer height, 80% infill, line pattern, and 175 mm/min speed was the best performer overall. Scanning electron microscopy confirmed that lower densities encourage crack initiation by connecting void morphology to fracture behaviour. For adjusting FDM-printed ABS parts to application-specific mechanical requirements, the combined RSM–TOPSIS framework provides dependable predictive models and decision-making guidance.

In this study, an amphoteric hydrogel composed of sodium Polyacrylate and cetyltrimethylammonium bromide (CTAB) was synthesized and evaluated for the adsorption of both cationic and anionic dyes from aqueous solutions. Three different CTAB concentrations (5%, 12.5%, and 25% w/w) were used to investigate the effect of CTAB on adsorption performance of the resulting hydrogel. Instrumental analysis confirmed the successful incorporation of CTAB into the polymer matrix, with porous and rough morphology. Modified hydrogel with 12.5% CTAB was the optimum one for further investigation. The optimized hydrogel exhibited high adsorption capacities for Methylene Blue (MB; 197.8 mg·g⁻¹) and Congo Red (CR; 170 mg·g⁻¹). Adsorption was rapid within the first hour, reaching equilibrium after ~ 2 h for MB and ~ 4 h for CR. Maximum uptake occurred at an adsorbent dose of 1.25 g/L for both dyes and the process followed the Freundlich isotherm and pseudo-second-order kinetics models. In the binary dye system, the hydrogel effectively removed both MB and CR simultaneously. The material also demonstrated excellent reusability, maintaining over 90% of its initial adsorption capacity after five successive adsorption–desorption cycles. Furthermore, it exhibited pronounced antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium, and Candida albicans, with inhibition zones of 16, 29, and 30 mm, respectively. Based on these findings, the prepared hydrogel is expected to be a promising material for removing both cationic and anionic dyes from dyeing effluents, as well as inhibiting the growth of pathogenic bacteria.

In this study, acetone-assisted interfacial polymerization (IP) was employed to fabricate thin-film composite (TFC) membrane with enhanced pervaporation performance. The selective polyamide layer was formed by the reaction of meta-phenylenediamine (MPD) and trimesoyl chloride (TMC) on hydrolyzed polyacrylonitrile (PAN) support. Acetone was introduced into the aqueous MPD phase at varying concentrations to regulate monomer diffusion and reaction kinetics at the interface of water and n-hexane. The influence of acetone content on polyamide membrane structure and intrinsic pervaporation separation performance was systematically investigated. Among the fabricated membranes, the TFC–A₇₅ membrane, prepared with 75 wt% acetone in the aqueous phase, exhibited superior separation properties. When tested with a 70 wt% isopropanol/water mixture at 25 °C, the membrane delivered a high permeation flux of 1199.5 ± 135.9 g·m⁻²·h⁻¹ and an outstanding water content of 99.42 ± 0.67 wt% in the permeate. Furthermore, the membrane maintained excellent separation efficiency across a wide range of feed temperatures and concentrations, confirming both its robustness and applicability for isopropanol dehydration.

In this work, a bio-based multifunctional composite film was fabricated by reinforcing a tung oil–natural rubber (N-TO) matrix with nano-ZnO via Diels-Alder modification and ultrasonic dispersion. The NR segments suppressed excessive crosslinking of tung oil, yielding a flexible semi-interpenetrating network, while well-dispersed ZnO nanoparticles enhanced thermal, photo-oxidative, and antibacterial performance. Compared with N-TO films, the ZnO-N-TO composite showed a significant increase in the initial decomposition temperature from 151.5 ℃ to 183.4 ℃ and in the residual carbon yield at 800 ℃ from 8.0% to 18.2%. Under UV irradiation, the color difference decreased from 9.6 to 3.1, reflecting more than 67% improvement in photo-stability. Antibacterial tests revealed clear inhibition zones of 6 mm against E. coli and 8 mm against S. aureus, whereas N-TO showed almost no activity. This work demonstrates a scalable and green approach to designing bio-based polymer films with integrated durability and antibacterial functionality, suitable for eco-friendly coatings and packaging applications.

Incorporating tea waste (TW) into hydrogel systems promotes sustainability and supports the principles of circular economy. A tea waste-grafted-polyacrylic acid/NPK (TW-g-PAA/NPK) slow-release fertilizer hydrogel (SRFH) was developed and compared with a polyacrylic acid (PAA) superabsorbent polymer (SAP) and TW-g-PAA superabsorbent polymer composite (SAPC). FTIR, SEM, and SEM–EDX analyses confirmed successful grafting, evidenced by a characteristic peak shift to 1046 cm⁻¹, and verified the presence of N, P, and K in SRFH. The SRFH exhibited the smallest pore size, lowest grafting efficiency (110%), yet highest mechanical strength (9.80 MPa compressive resistance) among the hydrogels. It also showed the lowest water absorbency capacity, leading to a slower release rate, but maintained excellent re-swelling ability over five cycles. Soil burial tests demonstrated SRFH's superior biodegradability (~ 80% weight loss in six weeks). In agricultural tests, SRFH-treated soil promoted the fastest germination and best growth of mini eggplant seeds. This work presents an eco-friendly, high-performance hydrogel fertilizer that enhances nutrient release, water retention, and mechanical durability for practical agricultural applications. Compared with previously reported hydrogel systems, the incorporation of TW improves cost-efficiency, network density, and swelling resilience. These findings advance the development of sustainable,high-performance hydrogels, offering practical insights for the polymer research community and real-world agricultural use.

Semicrystalline polypropylene (PP) undergoes changes in its mechanical and thermal properties over its lifecycle, primarily due to thermo-oxidative aging during the use phase and its exposure to environmental influences. This study examines the aging behavior and its effect on mechanical and thermal properties of PP, mainly used in the automotive industry, after accelerated thermal aging at temperatures of 120 °C, 135 °C, and 150 °C for one and three weeks. Thermo-oxidative aging, based on oxygen diffusion into the amorphous areas of the polymer, results in the damage of polymer chains near the surface due to oxidation. Since the degradation of PP is a heterogeneous process starting at the surface, we developed a new sampling method to analyze different aging phenomena across the sample’s cross-section. Using a microtome, we analyzed samples in differential scanning calorimetry (DSC) with a reproducible thickness at specific and defined depths. The reaction of oxygen with the radicals from polymer chains can be measured by changes in mechanical properties, a decrease in the melting temperature, and a shift in the size of the crystallites towards smaller structures. However, the presence of functional groups indicating degradation (carbonyl groups) could not be verified in infrared spectroscopy.

This work aims at investigating conductive polymer composites as potential coatings for bipolar plates (BPPs) to be used for PEM fuel cells (PEMFC). Various conductive fillers, including Ni-coated graphite, CrN, Monel, CuNi₃Si, Cu, and TiN were screened for conductivity. The most promising fillers were blended with epoxy resin stable under relevant testing conditions. The performance of the coatings was evaluated by means of ex-situ testing and characterisation (conductivity, interfacial contact resistance, SEM). A parameter study was carried out deploying the filler with the highest conductivity to optimise the coatings interfacial contact resistance. To demonstrate the potential of the proposed coating approach for high throughput processes the post-stamping process of the cured coatings was shown. Finally, a cost analysis based on bill of material (BoM) has been performed to benchmark the materials’ cost against other standard coating solutions, such as gold coating. Results show that for the first time, dense polymer-based coatings with high conductivity, low cost, and upscaling potential, and therefore broad applicability have been fabricated.