Fibers and Polymers最新文献

Delamination is a key concern during carbon fiber reinforced polymer (CFRP) composite drilling operations. These delaminated areas significantly increases the flammability risks when exposed to fire. The current research presents the flammability resistance of aluminium tri-hydroxide (Al(OH)₃)-modified epoxy resin as a flame-retardant edge-sealant for drilled CFRP composites. CFRP composites were manufactured using vacuum bagging method, followed by drilling with a 6 mm diameter drill bit. The samples were sized according to the ASTM standard D2863 and edge-sealed with Al(OH)₃-modified epoxy resin of varying weight percentages of Al(OH)₃ (25, 50 and 75 wt.%). Limiting oxygen index (LOI) tests were performed to measure the flammability of edge-sealed specimens in a given oxygen–nitrogen mixture. The results indicate that the edge-sealant significantly enhances the flame-retardant behavior by reducing the burn rate relative to neat CFRP composites. Specifically, the LOI of the CFRP composite edge-sealed with 75 wt.% of Al(OH)₃-modified epoxy resin is 6.64% higher than that of neat CFRP composite. Additionally, the burn rate was reduced by 55.88% compared to the neat CFRP composites. The findings of this study highlight the impact of drilling-induced delamination and the effectiveness of Al(OH)₃-modified epoxy resin as a flame-retardant edge-sealant, contributing to improved fire safety in CFRP composites.

In this study, due to its multifunctional nature, zinc borate (ZnB) was incorporated into electrospun polycaprolactone (PCL) fibers in various concentrations (1.5%, 3.5%, 5%, wt%). The homogenous fiber morphology, the varying fiber diameter distribution, and the presence of ZnB in PCL fibers were shown by SEM/EDS and FTIR analysis. TGA analysis revealed that the addition of ZnB into the matrix enhanced the thermal stability of polymer as evidenced by an increase in the temperature at 10% mass loss (T₁₀) from 365 °C to 390 °C. The fire-retardant performance of the PCL fibers, as assessed by the calculated limiting oxygen index (LOI), exhibited an improvement from 17.65 to 18.83 upon the incorporation of 5 wt% ZnB. Mechanical test results revealed that the tensile strength increased from 2.36 MPa to 3.46 MPa, while the Young's modulus decreased from 25.06 MPa to 17.99 MPa for PCL–Control and 5 ZnB–PCL fibers, respectively. ZnB–PCL fibers had potent antibacterial effects against both Gram-positive, Gram-negative, antibiotic-resistant bacteria, and fungal strains. Furthermore, cytocompatibility analysis using mouse fibroblast cells (L929) indicated that ZnB–PCL fibers supported cell adhesion, spreading and proliferation, even in 5 ZnB–PCL fibers containing the highest amount of ZnB. The development of a material that simultaneously exhibits broad-spectrum antimicrobial activity while supporting cell viability and proliferation is highly significant. In this context, the findings of this study suggest that ZnB–PCL fibers are promising candidates for wound dressings and tissue engineering scaffolds with improved mechanical and biological properties, as well as industrial fields requiring antimicrobial properties.

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This study investigates the influence of process parameters on particle incorporation in co-form meltblown nonwovens. We investigated loading efficiency as a function of particle size, insertion distance, and air pressure for aluminum oxide particles (300–600 μm) and polyether block amide (PEBA) elastomer polymer. The results demonstrate a statistically significant relationship between insertion distance and particle loading efficiency (p = 0.0001). Specifically, particle loading efficiency increased at greater distances from the die. Smaller particles exhibited higher capture efficiency compared to larger particles across all tested conditions. Air pressure also had a significant impact on particle loading within the tested range. Microscopic analysis revealed that particles are primarily mechanically entrapped within the fiber web. Surface treatments showed no significant improvements in fiber–particle interactions. Particle incorporation increased nonwoven thickness by 2.8–4.2 times and areal density by 2–6 times compared to controls. Fiber diameter of particle-loaded samples generally reduced with average diameters ranging from 5.9 μm (control) to 5.22–5.59 μm, where the 425 μm particles produce the finest fibers. Tensile strength decreased by ~ 15–16%, with smaller particles and, interestingly, resulted in a more isotropic behavior, while larger particles exhibited directional anisotropy. This investigation highlights the fundamental mechanisms governing particle incorporation in nonwovens and establishes clear relationships between processing conditions and loading outcomes.

Graphical Abstract

This study aims to develop the multifunctional air purification material integrating efficient formaldehyde catalytic degradation and PM2.5 interception capabilities by controllably synthesizing coconut shell-based activated carbon fiber loaded with mesoporous δ-MnO₂ (δ-MnO₂@ACF). Using ACF as the substrate, MnO₂ was loaded onto its surface via the hydrothermal method, with systematic investigation of the effects of hydrothermal temperature (90–180 °C), KMnO₄ concentration (0.005–0.05 mol/L) and reaction time (2–8 h) on the morphology and crystal phase of MnO₂. The highly active mesoporous δ-MnO₂@ACF composite was successfully prepared. Characterization techniques including SEM, XRD, and BET confirmed the mesoporous structure of δ-MnO₂ and its uniform loading on ACF. Formaldehyde (HCHO) removal tests demonstrated that δ-MnO₂@ACF achieved the removal efficiency of 92%, maintaining 76% efficiency after 6 cycles (150 min). Furthermore, the composite filter material fabricated based on this material exhibited not only outstanding formaldehyde degradation performance but also high PM2.5 interception efficiency (> 99%). This study provides a feasible strategy for developing multifunctional air purification materials combining catalytic oxidation and filtration properties, showing potential application value in indoor air pollution control.

The knitted-structure reinforced shape memory polymer composites (SMPCs) has the advantages of large recovery deformation while the weft plain knitted fabric reinforced SMPC has bad shape memory performance due to the feature of self-curling. To eliminate the influences of internal stress caused by self-curling, this work presents the mirror-symmetrical layup method to fabricate the multilayer weft plain knitted fabric reinforced SMPCs. The effects of layup numbers, loop densities and directions (0°/90°) on the shape memory properties of SMPCs under tensile and U-shaped bending load were systematically investigated. The results show that during both the tensile and U-shaped bending tests, the shape recovery ratios of SMPCs in the 0° direction are significantly higher than those of SMPCs in the 90° direction. As compared with the two-layers SMPC, the shape recovery ratios of six-layers SMPC with the tensile and U-shaped bending tests decrease. In contrast, the tensile and U-shaped bending recovery forces of six-layers SMPC in the 90° direction are obviously higher than those of the SMPC with two layers. The shape memory cycle tests of multilayer knitted SMPCs were also conducted to evaluate and discuss the stability of shape recovery ratio and recovery force of SMPCs under tensile and U-shaped bending load. These findings are beneficial for the structural design and optimization of SMPCs.

Natural dyeing employs eco-friendly, renewable colorants to enhance the aesthetic appeal of fabrics while promoting environmental sustainability. However, challenges like inconsistent color fastness and limited dye availability affect scalability. Integrating traditional motifs into woven and knitted designs helps preserve cultural authenticity. This study explores the application of natural dyeing on hemp and pineapple yarns, in blended forms, using the Rotation-Invariant Coordinate Convolutional Neural Network (RICCNN) to improve textile design. Natural fibers such as cotton, hemp, and pineapple were spun into yarn, including pure and blended forms (60:40 Cotton/Hemp (CH) and Cotton/Pineapple (CP)). These yarns were dyed using natural colorants extracted through ethanol and aqueous methods, aided by mordants. Each yarn type exhibited 8 shades in both aqueous and ethanol extractions, and a total of 80 dyed yarns were obtained. These yarns were selected to analyze breaking strength, tenacity, hairiness, linear density, weight loss, whiteness index, color strength, and yellowness index. Among pure and blended yarns, 60:40 Cotton/Hemp and Cotton/Pineapple blends demonstrated superior physical and dyeing properties, with aqueous extraction outperforming ethanol. The RICCNN was used to transform traditional Pichwa and Gond art motifs into woven and knitted fabrics. The performance of the proposed technique attains 28.31%, 27.3%, and 21.58% higher accuracy and 24.01%, 21.73%, and 28.28% higher precision compared with existing approaches like extraction, characterization, and properties assessment of pineapple leaf fibers from Azores pineapple (PLFAP-TGA), environmental multifunctional dyeing of pineapple utilizing Nyctanthes Arbor-tristis dye and Acacia nilotica bio-mordant (EMDP-FTIR) and New Brazilian pineapple leaf fibers for textile appliances: colonization with dyeing performance (NBPLF-SEM). The approach successfully transformed traditional motifs into woven and knitted textile designs, demonstrating cultural preservation and sustainable innovation.

Bone plates have been widely used for healing bone fractures, traditionally they have been made from metals like stainless steel, but that can cause issues like stress shielding. Flexible composite materials have been used to address these issues; however, they often lack load bearing ability in tibial fractures. To address this challenge hybrid bone plates are evolving combining both composites and metals. The healing of tibial fractures is influenced by the biomechanical environment at the fracture site, which is influenced by implant design, so in this study, different parameters of a composite bone plate were evaluated to assess their mechanical and biological effects on fracture healing. Initially, a parametric study was conducted by varying different parameters, such as the working length, screw configuration, metal part thickness, and screw spacing. The results showed that the working length, metal part thickness, and screw spacing significantly affected the fracture healing performance, whereas differences in screw configurations led to similar performance. Based on these results, 12 different cases were generated to determine a favourable combination of these parameters. The findings showed that the combination of a short working length, small screw spacing, and thick metal part of the composite bone plate offers a biomechanically favourable design for enhanced tibial fracture healing.

Textile-based capacitors hold great promise for wearable electronics; however, the development of devices that simultaneously achieve high performance, mechanical flexibility, and scalability remains a significant challenge. In this work, stainless steel/polyester blended yarn (SS/PET yarn) was employed to fabricate two three-dimensional interdigital electrode structures: the Equivalent Interdigital Electrode Structure of Conductive Yarn (CY-EIDES), based on high-SS-content yarn, and the Interdigital Electrode Structure with Randomly Distributed Conductive Fibers (RDCF-IDES), enabled by the random distribution of conductive fibers within low-SS-content yarn. The effects of SS content, yarn geometric parameters, and yarn arrangement on capacitance performance were systematically investigated. Experimental results reveal a conductive percolation threshold of approximately 9% in SS/PET yarn. CY-EIDES delivers a specific capacitance of 0.30 F/m at 25% SS content, whereas RDCF-IDES achieves a significantly higher value of 1.00 F/m at only 9% SS content, representing a 227.63% enhancement. Further analysis indicates that shorter yarn lengths, moderate SS diameters, and higher twist levels contribute synergistically to optimizing the capacitance performance of RDCF-IDES. This study demonstrates that the RDCF-IDES design enables efficient capacitor construction with minimal metal content, while maintaining excellent weavability and flexibility. The architecture is well-suited for integration into wearable energy storage systems and electromagnetic shielding textiles, offering a promising strategy for embedded capacitive components in next-generation flexible and wearable electronics.

Sputtering is an effective technique for coating various substrates. However, the high energy involved can cause damage to polymers. In this study, polyphenylene sulfide (PPS), an engineering plastic known for its excellent thermal properties, was coated with Cu to impart electrical conductivity. To activate the PPS surface and improve Cu adhesion, oxygen plasma treatment was applied prior to deposition; its effect on deposition and electrical properties was examined. The plasma treatment facilitated the attachment of oxygen species to the PPS surface, which significantly enhanced the copper deposition rate. Notably, electrical conductivity increased by a factor of 10¹² during sputtering, with conductivity being 1.75 times greater after plasma treatment compared to untreated samples. Additionally, no detectable deterioration in the thermal or mechanical properties of the PPS was observed. These findings suggest that the plasma-assisted sputtering process enhances the electrical conductivity of PPS and has the potential to broaden its industrial applications.