Journal of Polymer Research最新文献

In this study, polyamide 6 based composites containing 5 to 15wt% of a hybrid Aluminum Nitride, aluminum oxide filler system with bimodal particle sizes were prepared via in situ polymerization. Morphological analysis revealed that increasing the filler content to 15 wt% led to the development of a partially interconnected network, promoting thermal percolation. Differential Scanning Calorimetry and X-ray Diffraction showed that the fillers acted as heterogeneous nucleating agents, enhancing crystallinity and inducing the coexistence of α and ɤ crystalline phases. Various thermal treatments, including quenching, annealing, and isothermal crystallization, were applied to modify the crystalline structure and optimize filler arrangement. The isothermally crystallized sample exhibited the highest crystallinity (~ 71%), thermal stability (~ 428 °C), tensile modulus (~ 3182 MPa), and thermal conductivity (~ 1.39 W/m·K), due to improved crystal growth and dense filler packing. In contrast, the quenched sample exhibited reduced crystallinity and disrupted thermal pathways. Theoretical modeling using the Agari and Nielsen equations showed that the Agari model aligned more closely with experimental data, especially at higher filler contents, reflecting its ability to account for structural effects like percolation and crystallinity. These findings demonstrate that combining bimodal fillers with controlled thermal treatments can significantly enhance both the thermal and mechanical performance of polyamide 6 composites.

Modified polymer electrodes are of particular importance in analytical and environmental applications. The goal of this paper is the modification of a polymer surface for sensing applications and the detection of trace- metal ions in aqueous solution. This study offers a novel electrochemical sensing device to detection copper and cadmium ions, created via modifying a glassy carbon electrode GC with a polyimine based pyrrole by using square wave voltammetry. Polyimine polymer film was characterized and examined via Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV), and scanning electron microscopy (SEM). Spectroscopic devices were employed to identify the chemical structure of the prepared monomer, such as FTIR, ¹H NMR, ¹³C NMR, and mass spectroscopy. Furthermore, rate of scan effects on the electrical performance of the polyimine film was also examined. Electro- experimental data were employed to calculate coverage of surface’s substance and their electrical stability in blank solutions. Polyimine film thickness and the effects of (pH) of the medium were also investigated. Linear responses to Cu(II) and Cd(II) ions in the range of concentration (5 to 100 µg L^− 1) were acquired. Limit of detection (LOD) for the assay of Cu²⁺ and Cd²⁺ ions were 1.81 µg L^− 1 and 2.68 µg L^− 1, respectively. Encouraging results above indicated that modified polyimine films could potentially represent a viable candidate for electrochemical-sensor technologies.

This study presents the development and optimization of humic acid/polyvinyl alcohol (HA/PVA) supramolecular hydrogels via the Taguchi method and cyclic freeze–thaw processing. Humic acid was extracted from spent coffee grounds and incorporated into a polyvinyl alcohol matrix to fabricate physically crosslinked hydrogels. The structural, mechanical, and biological properties of these hydrogels were systematically evaluated, focusing on key formulation parameters such as HDOM (humic dissolved organic matter) concentration, crosslinker dosage, and freeze–drying cycles. The results revealed that the number of freeze–thaw cycles was the most influential factor in enhancing mechanical strength, while optimal HA content significantly improved compressive stress by ~ 40%. Scanning electron microscopy confirmed the formation of a porous network favorable for nutrient diffusion and cellular attachment. In vitro assays confirmed excellent cytocompatibility, with extract dilutions (25–75%) significantly enhancing fibroblast proliferation and migration compared to control. The wound healing assay further demonstrated accelerated scratch closure most notably in the 75% group highlighting the hydrogel’s strong pro-migratory effect and its promising potential for soft tissue regeneration. The combination of structural integrity, biocompatibility, and tunable bioactivity positions these HA/PVA hydrogels as promising materials for wound healing and tissue engineering applications.

In this paper, amino-terminated polymethylvinylsiloxane was synthesized via anionic ring-opening polymerization using Octamethylcyclotetrasiloxane (D₄), 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetravinyl cyclotetrasiloxane (D₄V), 1, 3-Bis (3-aminopropyl) -1, 1, 3, 3 tetramethyldisiloxane (AT) as precursors, followed by modification with epoxy resin. Subsequently, a hydrosilylation reaction with hydrogen-containing silicone oil was conducted. This process produced microspheres where the epoxy modification and crosslinking induced the formation of a surface micro-nano rough structure. This specific topography, combined with the low surface energy of polysiloxane, resulted in superhydrophobicity. The optimal formulation was determined through orthogonal experimental design. Under the conditions of 20 wt% epoxy resin content, a vinyl-to-active hydrogen ratio of 1:2, and hydrosilylation reaction parameters of 85 °C for 4 h, the microspheres exhibited superior hydrophobicity and surface morphology, achieving a water contact angle of 154.2°. They were incorporated into a polydimethylsiloxane (PDMS) matrix to fabricate light diffusion materials. The composite with 5 wt% loading exhibited an excellent balance of optical properties, achieving a high light transmittance of 82.4% and a high haze of 90.8% (> 770% increase compared to pure PDMS). Additionally, the composite surface maintained a hydrophobic state (WCA of 128.9°). These findings demonstrate the potential of these bifunctional microspheres in self-cleaning LED lighting applications.

Shape memory polyurethanes are smart materials that give back their original shape once stimulated by heat or water, rendering them ideal for certain biomedical applications such as minimally invasive surgery or drug delivery. In this research, dual-responsive SMPUs were synthesized successfully through the use of polycaprolactone (PCL) (2000/4000 g/mol) and poly(ethylene glycol) (PEG) (400/4000 g/mol) in a 30/70 weight ratio. Microstructural analysis showed that among all the parameters, crystallinity of the soft segments dominated in governing the elastic modulus because the crystalline regions were much stiffer than the hard segment domains. These SMPUs showed excellent mechanical properties with tensile strengths ranging from 5.8 to 11.2 MPa and elongation at break ranging from 150 to 310%. The shape memory behavior of these SMPUs was extraordinary with shape fixity ratios of greater than 95% and recovery ratios of 98% at 65 °C. They also attained almost 92% recovery in water at 37 °C. Thermal analysis (DSC) revealed that the dual-responsiveness is due to a “phase-switching” mechanism where the crystalline soft segments (PCL/PEG) constitute the reversible switch that fixes the temporary shape and releases it, and the hard segments form the permanent netpoints which memorize the original shape. The improved water-driven recoveries are further correlated to the increase of the overall crystallinity (from 32% to 46%), with high polyol molecular weights that enhance the switching. Thus, these results prove the suitability of the synthesized SMPU materials for advanced biomedical applications.

In this research, benzotriazole (BTA) is encapsulated as a corrosion inhibitor within bowl-shaped mesoporous polydopamine nanocontainers (MPDA), followed by decorating on the surface of the Ti₃C₂T_x MXene nanosheets and modifying with 3-aminopropyltriethoxysilane, and the synthesized Silane-MXene@MPDA-BTA is loaded in the weight percentages of 0.1 within solvent-based epoxy coating to apply on the carbon steel. The structure and morphology of the Silane-MXene@MPDA-BTA is considered using transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Besides, the corrosion resistance and self-healing performance of the nanofiller loaded epoxy coating are investigated by electrochemical impedance spectroscopy and salt spray tests. The results proved the barrier effect of the prepared MXene-based nanosheets through increasing the low-frequency impedance modulus to 9.76 × 10⁹ Ω.cm², compared to 9.35 × 10⁵ Ω.cm² for the blank sample after 60 days of immersion in the 3.5 wt% NaCl solution. Also, the self-healing efficiency of the scratched nanofiller system is about 94.5% (based on changes on charge transfer resistance) after 14 days of immersion.

Poly (Thiophene) (PTh) is familiar for optoelectronic applications due to strong absorption, better conductivity, and high charge carrier mobility. However, it found low photoluminescence efficiency and variations in electron carrier mobility due to reduced photoluminescence. The motto of current research is to overcome the above drawback and enrich the optoelectronic behaviour of PTh featuring 30, 40, 50, and 60 nm of zinc oxide (ZnO) nanoparticles (20 nm) via the electrochemical deposition method. This structure consists of 100 nm indium tin oxide (ITO), ZnO electron transport layer (ETL), ZnO/PTh active emission layer, PTh hole transport layer (HTL), and 80 nm silver top electrode. The influences of ZnO quantum dot layer thickness and silver top electrode on optical, electrical, stability lifetime, and X-ray diffraction behaviour of PTh quantum dot are evaluated. The structural analyses confirmed improved structural integrity, and the stability evaluations showed enhanced operational lifetime. The 50 nm ZnO:PTh active layer found better functional characteristics like reduced wavelength, enhanced electron voltage, higher photoluminescence efficiency, superior electron mobility, higher current density, and superior lifespan (life cycle), which are 3%, 4.5%, 61.5%, more than 100%, 107%, and more than 100% better than the PTh quantum dot LED.

This study reports advanced ballistic fabrics produced by impregnating p-aramid textiles with polyurethane-based gels and fluids derived from polyethylene glycol (PEG) and hydroxyl-terminated polybutadiene (HTPB), reinforced with silica (SiO₂), zinc oxide (ZnO), or boron carbide (B₄C) nanoparticles. The gels were synthesized via in situ crosslinking with 2,4-toluene diisocyanate (TDI), highlighting the potential of polyurethane-based systems for ballistic protection. Analyses revealed strong polymer–filler interactions and improvements in rheological, thermal, and mechanical properties. HTPB-based gels showed high hydrophobicity (contact angles > 110°) and superior ballistic performance compared to PEG-based systems. The HTPB–B₄C composite had the highest energy absorption, while ZnO-based gels achieved the highest projectile velocity limits. These results are comparable to values reported for STF-treated Kevlar® fabrics. To the best of our knowledge, this is among the first systematic comparisons between PEG- and HTPB-based gel systems reinforced with different nanoparticles, applied under identical ballistic testing conditions. Overall, nanoparticle-reinforced polymer gels emerge as promising, lightweight candidates for enhanced ballistic protection.

The thermal-mechanical properties of vulcanized styrene-butadiene rubber (SBR) are fundamentally determined by its cross-linked network structure. However, a systematic understanding of how cross-linking degree influences molecular dynamics and thermal transport remains limited. In this work, we investigate the dual micro-mechanisms through which cross-linking degree (Dc) governs both viscoelastic and thermal properties: namely, the restriction of chain segment mobility and modulation of low-frequency phonon density. The molecular dynamics (MD) simulations coupled with experimental validation are employed to investigate the effect of Dc on shear viscosity(η), bulk viscosity(η_b), specific heat capacity (C_p, C_v), and thermal conductivity(κ). Results demonstrate that increasing Dc enhances intermolecular constraints, leading to a rise in η by 65.5–23.3% and an increase in η_b by 6.6–11.1% under fixed shear conditions. In contrast, increasing shear rate ((dot {gamma })) promotes molecular chain orientation, thereby decreasing η by 83.4–93.2%, while simultaneously strengthening intermolecular forces and constraining chain movement, which increases η_b by 88.6–100.9%. Thermally, κ increases by 48.4% at Dc = 8.0 compared to Dc = 1.0, due to enhanced low-frequency phonon excitation within the tightened network. Furthermore, suppressed chain mobility reduces specific heat capacity by 8.9% (C_p) and 8.6% (C_v) over the temperature range of 300–330 K. These findings establish a clear microstructure–property relationship that elucidates the competing roles of chain dynamics and phonon transport in cross-linking elastomers, providing a theoretical basis for the rational design of vulcanized rubber with tailored multifunctional performance.

To enhance both the adhesive strength and cohesion of the adhesive resin, attapulgite (ATP) was chemically modified by peroxy groups to parepared ATP with initiation function (ATP-CPO). Subsequently, a series of high density polyethylene/ATP composites (HDPE/ATP) functionalized with maleic anhydride and vinyl trimethoxysilane were prepared via surface-initiated graft copolymerization. The effects of ATP-CPO dosage on the mechanical, thermal, rheological, and morphological characteristics of the composites were evaluated in detail. It was found that the surface functionalization and reactive extrusion process contributed to the nano-scale dispersion of ATP in the HDPE matrix, forming well-compatibilized nanocomposites consisting of HDPE-g-(MAH-co-VTMS), ATP-g-(MAH-co-VTMS), and more complex MAH/VTMS synergistically functionalized ATP-g-HDPE. When the ATP-CPO content was 4%, the composite exhibited significantly enhanced tensile strength, 180° peel strength, and shear strength, which were 1.4, 26.3, and 21.7 times higher than those of pure HDPE, respectively. Concurrently, the composites displayed higher melting and crystallization temperatures. However, the crystallinity decreased slightly, while the thermal stability was significantly improved. The melt exhibited more pronounced non-Newtonian behavior. Compared to the loss modulus, the storage modulus increased more significantly in the low-frequency region, and a non-terminal effect was observed, which enhanced the structural stability of the system under low-frequency shear stress.