Journal of Applied Polymer Science最新文献

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.

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.

Pre-oxidation is crucial in the production of polyacrylonitrile (PAN)-based carbon fiber. Traditional thermal pre-oxidation has high energy consumption and prolonged processing time. Irradiation technology can enhance pre-oxidation efficiency, but its influence on PAN fiber molecular structure is unclear. This work pioneers the application of molecular dynamics simulations integrating irradiation–thermal coupling to the PAN fiber two-phase molecular model, elucidating the nanoscale evolution of its amorphous and crystalline structures. Models for amorphous and crystalline regions were constructed, and atomic deposition and gradient heating simulations were performed to explore their impact on the two-phase structure of polyacrylonitrile. Irradiation lowered the initial cyclization temperature in both regions and initiated reactions in the amorphous region, which then spread to the crystalline region. Irradiation mainly reduced the minimum transition temperature of cyano groups in the amorphous regions of PAN by 40 K. It also caused significant atomic vacancies in the amorphous region and a “solidification” effect enhancing molecular chain stability in the crystalline region. These simulation results elucidate how irradiation–thermal synergy improves PAN fiber pre-oxidation efficiency, reduces energy use, and optimizes fiber structure, offering a strategy to enhance carbon fiber performance.

The low surface activity of basalt fiber (BF) hinders its capacity to establish an effective interfacial bond with natural rubber (NR). In this study, the surface of BF was modified with a silane coupling agent, KH172, to investigate the effect of different concentrations of KH172-modified BF on the properties of BF/NR composites. The findings of the physical and mechanical properties tests demonstrated that the mechanical properties of the composites were optimal at a concentration of KH172 of 1%, and the 300% constant tensile stress of the composites exhibited a 21.5% increase, the tensile strength exhibited a 13.3% increase, and the DIN abrasion and cutting quality exhibited a 7.7% and 8.4% decrease, respectively. The rheological properties test results demonstrated that the difference in energy storage modulus of the composites was generally reduced after the BF was modified by KH172, which effectively suppressed the aggregation of BF. The results of the dynamic mechanical properties test demonstrated that after BF was modified by KH172, the composites exhibited a decrease in resistance to wet sliding, while concurrently exhibiting enhanced vibration damping performance and reduced rolling resistance. This study offers a straightforward and expeditious approach to implementing BF in high-performance tires.

The accumulation of plastic waste raises serious concerns, which could lead to long-term issues with waste management, the environment, and the economy. Effects of irradiation followed by the soil burial test were investigated to accelerate the degradation of LDPE/PBS/PE-g-MA blends. In this study, low-density polyethylene (LDPE) was compounded with poly(butylene succinate) (PBS) incorporated with polyethylene-graft-maleic anhydride (PE-g-MA) compatibilizer. The effects were identified in terms of morphological, thermal, mechanical, and degradation properties. The existence of oxidized groups for irradiated samples proved the polymer oxidation. Exposure to 60 kGy increases the gel content of blends as a result of cross-linking. Meanwhile, the higher PBS ratios caused the dominant chain scission, resulting in the decrement of tensile strength (TS) with increasing doses. The higher roughness and brittle surface for the blends were noticed at 120 kGy than in unirradiated blends. Irradiation also leads to the formation of a preoxidized sample, subsequently enhancing the degradation. The reduced intensity of oxygen-based groups proves the degradation due to microbial attack. The increase in surface roughness and holes for irradiated blends after the degradation was noticed. Therefore, the synergistic effect of irradiation and burial tests has the potential to accelerate the degradation of LDPE/PBS/PE-g-MA blends.

Compared with polypropylene homopolymer (PP-H), polypropylene random copolymer (PP-R) contains ethylene units that disrupt chain regularity and enhance chain mobility, which is expected to improve the solubility of foaming agents and promote foaming performance. However, PP-R still suffers from low melt strength as PP-H. In this study, high melt strength polypropylene (HMSPP) was prepared from both PP-H and PP-R via reactive extrusion, using benzoyl peroxide (BPO) as the initiator and vinyl polydimethlsiloxane (VS) and styrene (St) as grafting monomers. The melt strength of HMSPP-R reached 69.6 cN, which is 20.5 times that of PP-R, while HMSPP-H reached 55.9 cN, only 8.6 times that of PP-H. Combined with the rheological results, it suggests that HMSPP-R contains more branched structures than HMSPP-H. Foaming results showed that HMSPP-R achieved a maximum expansion ratio of 28.7 times, while HMSPP-H can only achieve up to 24.1 times. Solubility tests and molecular dynamics simulations further revealed that HMSPP-R has a larger free volume, enhancing the solubility of CO₂ and thus improving foaming performance. This study holds significant industrial guidance value for the preparation of HMSPP suitable for foaming.