Journal of Applied Polymer Science最新文献

To enhance the mechanical strength and chemical resistance of waterborne polyurethane coatings, modified graphene oxide (HGO) was incorporated into cationic waterborne polyurethane (CWPU) via stepwise polymerization to yield HGO/CWPU composite coatings. By modifying GO with bis(triethanolamine) diisopropyl titanate, a triple-action network of electrostatic attraction, hydrogen bonding, and covalent crosslinking was established within the CWPU matrix, enhancing the compatibility and interactions between GO and the polymer. Well-dispersed HGO lamellae within the CWPU matrix created a physical barrier that markedly improved the mechanical strength, water resistance, and corrosion resistance of the coatings. The tensile strength of the HGO/CWPU-0.7% composite coating reached 31.97 MPa, which was 4.54 times higher than that of pristine CWPU (7.05 MPa). This decreased the water absorption by 53.03%, while the corrosion current density dropped by three orders of magnitude, resulting in a corrosion prevention efficiency of 99.98%.

Optically transparent amorphous copolyarylates based on tetramethylbisphenol A (TMBPA) and bisphenol B (BPB) were synthesized via low-temperature interfacial polymerization. These copolyarylates exhibited high solubility, with number average molecular weight (M _n) of 1.48 × 10⁴–1.92 × 10⁴ g/mol, weight average molecular weight (M _w) of 6.64 × 10⁴–9.13 × 10⁴ g/mol, polydispersity index (PDI) of 3.45–5.89, and intrinsic viscosity of 0.62–0.83 dL/g. Incorporation of TMBPA alters the thermal properties of the copolyarylates, decreasing thermal stability (T _5%) from 473.4°C to 444.4°C and char yield from 34.6% to 19.7%, but increasing the glass transition temperature (T _g) from 202.9°C to 234.1°C. TG/FTIR and Py-GC/MS analysis revealed that methyl groups adjacent to the phenolic hydroxyl group promoted chain breakage and accelerated thermal decomposition. The main gaseous products included H₂O, CO₂, CO, CH₄, and phenolic compounds. Tensile strength, tensile modulus, and elongation at break of copolyarylates ranged from 51.83 to 60.21 MPa, 1023.28 to 1283.14 MPa, and 32.9% to 53.6%, respectively. This study highlighted the solubility-thermal property balance, providing insights for designing processable high-performance polyarylates.

Flexible strain sensors, as crucial components of smart wearable devices, have garnered significant attention in fields such as human health monitoring. However, developing flexible strain sensors with high strength, sensitivity, extensibility, and long-term stability remains a challenge. In this study, a straightforward method was successfully developed for fabricating a cross-linked, conductive flexible strain sensor based on polyaniline/3-aminobenzenesulfonic acid-epoxidized natural rubber (PANI/3-ABSA-ENR) with a cross-linked structure. This was achieved by grafting 3-aminobenzenesulfonic acid (3-ABSA) onto epoxidized natural rubber (ENR) nanospheres, followed by in situ polymerization of aniline (ANI) onto the rubber nanospheres to form an effective cross-linked structure. At a PANI content of 13 wt% (PANI/ENR), the conductive flexible strain sensor exhibits outstanding comprehensive performance. Consequently, this strain sensor demonstrates ultra-high tensile strength (approximately 10 MPa), a wide strain range (approximately 1200%), and long-term reliability (2500 cycles at 50% strain). Simultaneously, the PANI/3-ABSA-ENR strain sensor exhibits a high gauge factor (GF = 21.6) and short response time (230 ms). Furthermore, this strain sensor can detect and capture both subtle and large-amplitude human motion signals, such as those from limb joints, cheeks, and mouth. This demonstrates the PANI/3-ABSA-ENR strain sensor's broad application potential in smart wearable devices.

This study conducted a comprehensive comparative analysis of the mechanical properties, surface morphology, hydrophobicity, microstructure, and crystallization behavior of methyl vinyl silicone rubber (MVQ) and its composites (MVQ/opal and MVQ/g-opal@CeO₂) under both extreme dry-heat and natural aging conditions. The results demonstrated that the incorporation of g-opal@CeO₂ significantly improved weathering resistance. Under extreme dry heat aging, the MVQ/g-opal@CeO₂ composite exhibited a tensile strength loss of only 7.13% and a hardness increase of 4.6 HA, significantly superior to the 13.05% loss and 6.4 HA increase in pure MVQ. Similarly, during natural aging, the composite showed a minimal tensile strength decline of 5.0% compared to 10.44% for MVQ, while maintaining a high contact angle (decreasing only from 123° to 120°). These improvements were attributed to the combined effects of Ce³⁺/Ce⁴⁺ redox-mediated oxidative protection and UV absorption, which effectively delayed Si–C bond degradation and suppressed the formation of Si–O–Si network structures. Furthermore, prediction models based on Back Propagation (BP) neural networks were developed to characterize the evolution of tensile strength, achieving determination coefficients exceeding 0.9 under both conditions.

Biodegradable polycaprolactone (PCL) films were developed with 13% w/w ethanol extract from industrial peanut skin residues (PSE), a rich source of natural antioxidants and antimicrobials. Films retain actives during processing. Antioxidant activity was evaluated via total phenolics, flavonoids, condensed tannins, and radical scavenging assays (DPPH, ABTS). PSE incorporation enhances oxidative thermal stability, increasing oxidation onset temperature (OOT) by 61°C—eliminating the early oxidative stage of neat PCL—and extending oxidation induction time (OIT), without compromising suitability for food packaging. Oxidative stability is maintained after accelerated storage (90 days at 40°C) and repeated migration tests simulating contact with refrigerated fatty foods. Migration assays confirm effective release of actives under repeated use. Mass transfer parameters were obtained by fitting experimental data to Fick's second law and the Arrhenius model, yielding intrinsic diffusion coefficients in 95% ethanol from 5°C to 40°C (4.17 × 10⁻¹⁵–7.1 × 10⁻¹⁴ m²·s⁻¹), eliminating swelling at 40°C. Coefficients fall within typical polymer–antioxidant ranges, reflecting strong retention and controlled release due to the PCL matrix and complex PSE mixture. Overall, the films demonstrate long-term chemical and functional stability, enhanced thermo-oxidative resistance, and controlled antioxidant release, supporting their application in refrigerated, lipid-rich foods within a circular economy framework.

Poly(N-vinylpyrrolidone) (PNVP) and its block copolymers with chlorophenylmaleimide monomers (chloro group substituted at ortho OCPMI, meta MCPMI, and para PCPMI positions) were synthesized using ethyl (S)-2-(ethyl isobutyrate)-(O-ethyl xanthate) (EIEX) as a xanthate mediator. The resulting block copolymers PNVP-b-POCPMI (ortho-chlorophenyl maleimide), PNVP-b-PMCPMI (meta-chlorophenyl maleimide), and PNVP-b-PPCPMI (para-chlorophenyl maleimide) were characterized using ¹H NMR, FTIR, DSC, TGA-DTA, GPC, and XRD. These block copolymers, with both hydrophilic and hydrophobic segments, were found to self-assemble into nanoparticles in aqueous solutions, which were further studied using transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cytotoxicity was assessed via the MTT assay on Dalton's lymphoma (DL) cells treated with polymer concentrations ranging from 5 to 100 μM. Nuclear morphological changes in Dalton's lymphoma (DL) cells were analyzed using DAPI and AO/EtBr staining. The block copolymers demonstrated anticancer activity, with higher cell viability observed at increased polymer concentrations, suggesting their potential for future development in human anticancer therapies.

Nitrile butadiene rubber (NBR) and hydrogenated nitrile butadiene rubber (HNBR) were blended at different weight ratios, with spherical nano-alumina (nano-Al₂O₃) as the reinforcing filler. The vulcanization behavior, cross-linking density, mechanical performance, wear resistance, and wear mechanisms of the NBR/HNBR composites filled with nano-Al₂O₃ were systematically characterized via vulcanization curve analysis, equilibrium swelling tests, tensile and compression tests, friction-wear measurements, scanning electron microscopy (SEM) observations, and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Results reveal that the torque difference and cross-linking density of the composites exhibited nonlinear variations with increasing the ratio of NBR to HNBR. Notably, the composite with an NBR/HNBR weight ratio of 70:30 achieved superior mechanical properties and optimal wear resistance, accompanied by the lowest volume wear rate among all tested formulations. The key insight is that the NBR/HNBR ratio of 70:30 facilitated the formation of a synergistic interpenetrating cross-link network. NBR contributed abundant cross-link active unsaturated double bonds to densify the network, while the saturated main chain of HNBR imparted structural stability and inhibited crack propagation. This work provides a feasible strategy for optimizing rubber composites by regulating NBR/HNBR blending ratios, offering guidance for the design of high-performance rubber materials for tribological applications.

The selective removal of nickel ions (Ni²⁺) from multicomponent wastewater represents a significant environmental challenge. In this study, a novel composite hydrogel microsphere adsorbent, PVA/AMPy-SH, was developed by synergistically integrating a polyvinyl alcohol (PVA)-reinforced starch network for structural stability and 2-(aminomethyl)pyridine (AMPy) as a specific chelating ligand for Ni²⁺. This synergistic design, which integrates the PVA network with AMPy functionalization, relative to conventional adsorbents, provides improved mechanical strength, enhanced adsorption capacity, and superior ion selectivity. The adsorption process followed the Langmuir isotherm model, with a fitted maximum adsorption capacity of 272.64 mg g⁻¹, and the adsorption kinetics were consistent with the pseudo-second-order kinetic model. Notably, the adsorbent demonstrated exceptional selectivity toward Ni²⁺, with separation factors (β) reaching 56 against competing ions, and retained 86.13% of its initial adsorption capacity over six consecutive adsorption–desorption cycles. This work presents a rational design strategy for developing reusable adsorbents for targeted metal recovery from complex wastewater systems.

This study investigated the degradation behavior of poly(lactic acid) (PLA) films and PLA/polystyrene-grafted hectorite (PLA/Hec-g@PS) nanocomposite films in aqueous solutions of varying pH (neutral, acidic, alkaline). The results demonstrated that water molecules play a critical role in the degradation process. Compared to pristine PLA films, the Hec-g@PS nanocomposite films significantly enhanced the hydrolytic resistance of PLA, effectively mitigating surface damage and crack formation. Analysis using a first-order kinetic model revealed that the degradation reaction rate constants for PLA/Hec-g@PS films were consistently lower than those for pristine PLA films across all tested environments (neutral, acidic, alkaline). This performance improvement is attributed to the incorporation of Hec-g@PS, which increases the crystalline regions within PLA, reduces the exposure of ester groups in the amorphous domains, and restricts water molecule diffusion due to its hydrophobic nature, thereby synergistically retarding the hydrolysis process. Further research focused on the PLA/Hec-g@PS nanocomposite films elucidated the mechanism by which Hec-g@PS influences PLA microplastic (PLA-MPs) generation: Hec-g@PS effectively reduces the quantity of PLA-MPs formed during degradation and inhibits microplastic shedding. Mechanistic studies verified that Hec-g@PS optimizes the arrangement of PLA chain ends through intermolecular interactions, resulting in a denser structure that lowers the potential for microplastic release during degradation.