Journal of Applied Polymer Science最新文献

Thermal oxidative aging, the primary cause of natural rubber degradation during storage or use, can be effectively mitigated by designing covalent cross-linking interfaces between nanofillers and rubber, which provides a simple and highly efficient way to prolong service life. In this work, the active thiol groups were modified on the surface of graphene oxide (GO, radial dimension: ~10 μm) through photochemical grafting to facilitate the covalent interface cross-linking effect between GO and natural rubber (NR). The photocatalyzed thiol-vinyl-mediated click reaction between –SH and –C═C– of NR was established at the interface. The thiol groups modified GO (GS), used as filler, were uniformly dispersed in the NR matrix and formed beneficial covalent interactions with the NR chains. The obtained GS modified NR (NR/GS) composite exhibited excellent mechanical properties and aging resistance in air after the vulcanization process. The tensile strength of the NR/GS composite could reach up to 26.99 MPa, while its heat resistance index reached as high as 176.6°C. Additionally, the composite exhibited significantly improved resistance to thermal oxidizing aging properties. This synthetic strategy provides a robust method for the improvement of covalent interfacial interactions between NR and the GS sheets during the latex stage.

Hybrid poly(amide imide) (PAI) ultrafiltration (UF) membranes were successfully fabricated using MOF-808 for the separation of bovine serum albumin (BSA) and humic acid (HA). The zirconium-based MOF-808 was synthesized by a straightforward solvothermal process, and its chemical functionality was confirmed by FTIR and XRD. The crystalline and granular structure of MOF-808 was clearly visible in scanning electron microscope (SEM) images. The surface functionalities of the membranes were analyzed using FTIR and XRD. The PAI membrane containing 4 wt.% of MOF-808 exhibited a contact angle (CA) of 57.8°, water uptake of 75.1%, pure water flux (PWF) of 139.2 Lm⁻² h⁻¹, and porosity of 27.4%, indicating increased surface hydrophilicity of the hybrid membranes. The antifouling behavior was evaluated using BSA and HA foulants. The flux recovery ratio (FRR) of the hybrid membranes increased to above 90% during the rejection of BSA and HA, demonstrating their antifouling properties and excellent separation ability. Overall results clearly show that the PAI/MOF-808 hybrid UF membranes are promising for water and wastewater treatment.

Pore-filled anion exchange membranes (AEMs) were fabricated by impregnating a porous polytetrafluoroethylene (PTFE) support with a cross-linked poly (vinyl benzyl chloride) (PVBC) matrix and graphene oxide (GO) nanoparticles. The influence of GO loading (0.5–7 wt%) on membrane performance was evaluated. Structural and thermal analyses confirmed uniform pore filling and stable GO integration within the polymer matrix. The optimized membrane containing 5 wt% GO exhibited an ion exchange capacity of 1.47 meq/g, water uptake of 48%, and tensile strength of 24.85 MPa, along with improved hydrophilicity and alkaline stability. Excessive GO incorporation led to nanoparticle agglomeration and performance decline. Compared with previously reported PTFE-based AEMs, the developed membranes combine enhanced mechanical robustness with competitive conductivity and chemical stability. These results demonstrate that controlled nanoparticle incorporation is a promising strategy to improve the durability of AEMs for electrochemical energy and water treatment applications.

This study presents a flexible, platinum-free counter electrode for Dye-Sensitized Solar Cells (DSSCs) using polyvinyl alcohol (PVA) as the substrate. Incorporating graphene oxide (GO) and PEDOT:PSS significantly enhanced electrocatalytic activity and conductivity of the electrodes. The optimized PVA/GO/PEDOT:PSS showed reduced cathodic peak separation ΔEp = 0.62 V, indicating improved reaction kinetics. The incorporation of GO enhanced the thermal stability of the composite, as indicated by significant shifts in mass loss temperatures during thermal analysis. Together with the high tensile strength and flexibility demonstrated in mechanical tests, these results support the improved structural integrity of the material. Such properties make the composite suitable for integration into flexible devices while maintaining crack-free surfaces. The synergy between GO and PEDOT:PSS also increased surface area and electrical conductivity, enhancing redox efficiency. These results demonstrate the potential of this platinum-free electrode to replace traditional platinum-based materials in DSSCs, offering a more cost-effective and sustainable solution for solar energy applications.

Conductive hydrogels show great potential for flexible sensors, yet their applications are limited by low strength, poor freeze resistance, and easy dehydration. To address these issues, this paper developed a multifunctional PVA (polyvinyl alcohol)/CMC (carboxymethyl cellulose sodium)/PANI (polyaniline)/PA (phytic acid)/BA (boric acid)/Fe³⁺ hydrogel (denoted as PMNF) with a double-network structure formed via the Hofmeister effect and in situ polymerization. The hydrogel exhibits excellent mechanical properties (tensile strength: 236 kPa; elongation: 541%), high conductivity (2 S/m), and improved antifreezing behavior. At −12°C, it retains a conductivity of 0.86 S/m and over 300% elongation. It also demonstrates strong water retention after 15 days and stability in acidic/alkaline salt environments. Based on these properties, PMNF-based sensors reliably detect both subtle and large human motions under various conditions. This work offers a practical strategy for developing robust wearable electronics suited for real-world use.

Recycled polyolefin (rPO) is a promising material for sustainable applications, but its use is limited by the release of volatile organic compounds (VOCs), which cause odor and reduce indoor air quality. This study introduces a strategy to address this issue by chemically modifying halloysite nanotubes (HNTs) to improve their VOC adsorption efficiency and multifunctional performance in rPO. HNTs were functionalized through a three-step process involving N-[3-(trimethoxysilyl)propyl]ethylenediamine (TMPED), monochloroacetic acid (MCA), and hydrazine hydrate (HH), producing amine-rich surfaces. Modified HNTs were incorporated into rPO at 2 and 5 wt% and compared with unmodified HNTs. VOC reduction was assessed using headspace gas chromatography–mass spectrometry (HS GC–MS) and jar testing, while structure and properties were analyzed by FTIR, NMR, TGA, DSC, SEM, BET, and tensile tests. The 5 wt% TMPED-MCA-HH-HNT composite reduced total VOC intensity by 91%, particularly, key odorants such as acetaldehyde and cyclotrisiloxane. This effect is attributed to dual action: physical adsorption in the HNT lumen/mesopores and selective chemisorption via hydrogen bonding and Schiff base formation between amine/hydrazide groups and polar VOCs. Thermal stability, tensile modulus (+25.3%), and crystallinity (73.4%) were also improved. These findings highlight functionalized HNTs as efficient additives for enhancing both the mechanical and odor performance of rPO.

Green hydrogels hold promise for biomedical applications but are limited by weak mechanical properties. Here, we report a chitosan (CS)–reinforced polyvinyl alcohol hydrogel (PVA) fabricated via eco-friendly freeze–thaw cycles, achieving dual enhancement in mechanical strength and antibacterial efficacy. Incorporating 3 wt% chitosan increased compressive strength from 0.36 MPa in pure PVA to 2.92 MPa at 80% strain, while maintaining over 80% recovery after cyclic compression. The porous structure of the fabricated hydrogel and hydrogen-bonded network enabled sustained ciprofloxacin (CIP) release over 72 h. Antibacterial performance against Escherichia coli and Staphylococcus aureus improved significantly with CS addition, reaching 99% efficiency at 3% CS content, while CIP integration achieved complete bacterial eradication (100% efficiency). Synergistic action between the contact-based bactericidal activity of CS and CIP sustained release eliminated colony formation, demonstrating superior inhibition of both Gram-negative and Gram-positive bacteria. This green strategy delivers a mechanically robust, multifunctional hydrogel for infection-resistant biomedical applications.