Fibers and Polymers最新文献

Due to the lack of efficient and stable recycling methods and processes, the waste of carbon fiber-reinforced polymer (CFRP) poses a threat to the environment, while a large number of demand every year requires a lot of cost and energy to be used in manufacturing carbon fiber (CF). Therefore, there is an urgent need to develop an economical and efficient recycling process to deal with waste CFRP. In this study, CFRP in N-methylpyrrolidone (NMP) solution was swelled with the assistance of microwave irradiation. And the high efficiency and fast characteristics of microwave irradiation promoted the swelling of CFRP in NMP, which greatly reduced the pretreatment temperature and time. The CFRP was successfully swollen at 80 °C for only 0.5 h, then, they were decomposed in 8 M nitric acid for 7 h, the decomposition rate reached 74.6%, which greatly improved the reaction rate and finally retained about 70% of the CF mechanical properties. This method is helpful to reduce energy consumption in the recovery process and improve the stability of recycled CF (rCF), which provides a new direction and theoretical support for the recovery and reuse of CF.

Bacterial cellulose (BC), known for its three-dimensional nanofibrous structure, is a sustainable material with broad applications. However, BC’s high rigidity, when dehydrated, limits its utility in diverse industries such as fashion and healthcare. This study aims to overcome these limitations by a sustainable modification approach of dehydrated BC derived from Acetobacter xylinum (commercially produced by Minh Tam Coconut Co., Ltd. – Vietnam) using polyethylene glycol (PEG) and electron beam irradiation (EBI), a cutting-edge, fast, chemical additive-free, and waterless technology, with various absorbed doses (0, 50, 100, and 200 kGy), to fabricate a BC-based interpenetrating polymer network (IPN). Consequently, at an absorbed dose of 200 kGy, the EBI-BC/PEG exhibits significant cross-linking effects, enhancing softness with a 17-fold reduction in bending modulus (166.3 ± 41.0 MPa), decreased flexural rigidity (49.2 ± 12.1 µNm), improved thermal conductivity with a threefold increase in maximum heat flux (0.256 ± 0.024 W/cm²), and increased areal density of bonded PEG (148.7 ± 21.5 g/m²) compared to untreated BC. Besides, tensile strength (26.1 ± 2.5 MPa), and strain percentage (4.5 ± 0.5%) of EBI-BC/PEG (200 kGy) decrease relative to unirradiated BC/PEG (0 kGy), these properties are still improved better when compared to untreated BC. Additionally, EBI-induced cross-linking improves thermal degradation temperature. Besides, EBI-induced oxidation enhances moisture regain and reduces the contact angle compared to unirradiated BC/PEG. This research provides foundational insights into BC modification by EBI to address current limitations, especially applying in textile and leather industries, promoting sustainable development.

Graphical Abstract

Carbon fiber fabric composites as a multiphase material have excellent mechanical properties such as high specific modulus, stable performance, and high temperature resistance. However, such as two-dimensional fabric composites are prone to invisible damage or even delamination after being subjected to out-of-plane impact, so to enhance the delamination resistance of the composites, bundled fibers are introduced in the direction of the thickness of the composites to form 3D fabrics, but due to the 3D fabric composites are subjected to out-of-plane load, the bundled fibers undergo deformation and curling, which seriously affects the in-plane properties of the composites. In the study of impact and damage resistance of composites, it is necessary to study the damage mechanism and understand the influence of fiber structure on its performance and failure form. However, there is a lack of research on the compression-after-impact (CAI) properties of 3D composites. This paper focuses on the progress of research on the damage of 3D interlaminar orthotropic fabric composites after low-velocity impacts (LVI) and the damage problem in post-impact CAI. The effects of fiber structure on CAI compression performance and damage mechanism of composites are studied in depth with the help of a new finite element model by combining experiments and finite element simulation. Finally, the development trend of the damage problem of 3D fabric composites and the future research content are discussed.

Collagen is a biomaterial whose properties are influenced by its origin. The objective of this study is to extract, purify, and characterize collagen from fish residues (tilapia scales) and fabricate and characterize collagen-polyvinyl alcohol (PVA) fibrous membranes using the electrospinning technique. Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis (SDS-PAGE) were used to characterize the collagen and the membranes. The results showed that tilapia scales are an important source of natural collagen and recorded a final yield of 2.5% wt. In addition, the membranes showed excellent properties that make them suitable for use as scaffolds for various applications using a 50:50 wt. solution of collagen and PVA. The biological evaluation of electrospun scaffolds was done by a culture of Human Foreskin Fibroblasts (HFF-1) cells as an in vitro model, and alamarBlue™ assays were conducted to determine the growth and cytotoxicity. The results indicate that this biomaterial has promoted cell proliferation, and the scaffolds exhibited a favorable behavior for cell growth over time in laboratory tests. Therefore, collagen extracted from tilapia scales can be potentially applied in several applications related to tissue engineering, such as graft substitutes, cartilage repair, among others.

Graphical Abstract

Sustainable bio-based composites are eco-friendly alternatives to conventional composites. This study aimed to recycle natural fiber textile waste into sustainable bio-epoxy composites and investigate their mechanical properties. Textile waste strips (100% cotton denim fabric) were segregated and reinforced using bio-epoxy. Composites were prepared with four stacking sequences, comprising S1: (0)₄, S2: (0/90)₂ with interlacement, S3: (0/90/0/90), and S4: (0/− 45/90/ + 45), with a similar fiber volume fraction. The mechanical performances of the composites were investigated via three-point bending, low-velocity impact (LVI), Charpy impact, and tensile tests using three-dimensional digital image correlation. S3 and S4 exhibited the lowest and highest bending strengths, respectively, in the longitudinal direction. In the transverse direction, there were no major differences in the bending strengths of S2, S3, and S4; however, S1 showed a decrease of up to 50%. In the LVI tests, S4 and S1 exhibited the highest and lowest impact resistances, respectively. In the Charpy impact test, S4 exhibited the maximum resistance to failure. In the tensile test, S1 exhibited the highest tensile strength in the longitudinal direction, followed by S4, S2, and S3. The results demonstrated that the interlacement and stacking sequences significantly affected the mechanical performance of each composite.

The present study explores the enhancement of kenaf fiber-reinforced vinyl ester composites using natural fillers, specifically roasted chickpea powder and silanized tamarind shell biomass powder, to improve mechanical properties, moisture resistance, and interfacial bonding. The uniqueness of this research lies in the combination of surface modified kenaf fiber along with these hybrid fillers, which has not been previously studied. Vinyl ester resin, known for its strong odor and volatile content during curing, is utilized with various additives, such as methyl ethyl ketone peroxide (MEKP), cobalt naphthenate, and DMA, to accelerate the curing process and enhance performance. Roasted chickpeas and tamarind pods are prepared as biofillers by grinding them into fine particles. The biofillers undergo surface modification treatment using 3-APTMS to improve adhesion with the matrix and reinforcement. Composite fabrication is achieved through the hand layup method, followed by ambient and post-curing processes to achieve a stiff structure. The experimental results indicate that the specimen VKC2, containing 3 vol.% silane-treated chickpeas shell filler, exhibits the best mechanical properties with a tensile strength of 155 MPa, flexural strength of 185 MPa, ILSS of 35 MPa, impact energy of 5.8 J, and hardness of 82 Shore-D. These superior values are due to optimal filler dispersion and enhanced interfacial bonding, resulting in efficient load transfer. Specimen VKC3, with 5 vol.% silane-treated chickpeas shell filler, shows the best wear properties with a specific wear rate of 0.015 mm³/Nm and a COF of 0.22, the highest thermal conductivity at 0.53 W/mK, and water absorption of 0.41%. These properties are attributed to the filler creating a dense structure, enhancing wear resistance, forming continuous thermal conduction networks, and moderating moisture uptake. SEM analysis reveals uniform dispersion of fillers, enhancing properties, while agglomeration leads to weaker performance, reinforcing the significance of proper filler content and treatment for optimized composite performance.

Thin-walled deployable composite booms (DCB) possessing excellent strain abilities have high demand in the current space industry. They help in compact packaging of large volumes during various space activities and have superior stowability when it is fabricated with a lenticular cross-section. The work carried out aims to investigate the most efficient cross-sectional parameters for a thin-walled DCB fabricated with high strained carbon fiber reinforced composites. The study utilized ABAQUS software to run computational analysis of the tensile test, to determine the strain energy attained, maximum force developed, and the stress and strain distribution over the cross-section. The analysis was done by varying cross-sectional parameters such as radii of curvature and thickness along the cross-section of the boom. The results were obtained for strain energy, maximum force, stress and strain distribution along the cross-section for varying cross-sectional design parameters. It was found that when curvature radii rise, the strain energy as well as force developed decreases. The force value dropped from 120.8 N to 53.62 N as the radius of curvature increased from 24 to 44 mm in the 0.4 mm model segment, indicating that less the radii more is the force required for flattening the structure. From stress and strain distribution, the areas prone to high stress and strain were at inflection points. Thus, the present study helps the designer to select the appropriate geometric parameters of lenticular DCB suiting the application.

Bone defects challenge human health, highlighting the need for new therapies. This research aims to develop and characterize a PCL/PAN/casein (PCL/PAN/CA) scaffold and to assess the attachment, growth, and differentiation of endometrial stem cells (EnMSCs) into osteoblasts for potential use in bone tissue engineering (BTE). In this study, 0.5 g of PCL and PAN were individually dissolved in 5 mL of DMF and electrospun to prepare PAN and PCL scaffolds. The nanofiber surfaces were then coated with casein. The scaffolds’ chemical characteristics were examined through scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) techniques. Additionally, the biocompatibility and cytotoxicity of the scaffolds on EnMSCs were evaluated through the MTT test, acridine orange staining, and DiI labeling. The differentiation of osteoblasts on the synthesized scaffolds and the role of casein in cell growth and differentiation were examined. Additionally, Masson’s trichrome staining was utilized to assess the healing process of bone lesions in rat models after scaffold grafting. The results indicated that the fabricated scaffolds exhibited a nanofibrous structure, with diameters of 370 nm for PCL, 250 nm for PAN, and 290 nm for PAN/PCL. The PAN/PCL/CA scaffold showed the most significant osteoblast proliferation and differentiation levels. In animal studies, grafting the PCL/PAN/CA scaffold led to a 31% improvement in recovery compared to the control group and the PCL/PAN scaffold on its own. The PAN/PCL/CA scaffold demonstrated a remarkable capacity to facilitate the proliferation, growth, and differentiation of EnMSCs, underscoring its promising suitability for applications in BTE.

To address the issues of signal crosstalk and discomfort between multifunctional sensors, this paper presents a novel design and integration approach that combines the capacitive pressure sensing mechanism of a fabric dome structure and the temperature sensing mechanism of ionic liquids/thermoplastic polyurethane elastomers/sewing threads (IG/TPU/ST), demonstrating a superhydrophobic and breathable bimodal tactile sensor with no crosstalk between pressure and temperature responses. The sensor has a pressure sensitivity of up to 0.043 kPa⁻¹ (in the range of 0–6.84 kPa), a wide detection range of 0–223 kPa, a fast response time of 120 ms, and excellent stability (12,000 compression cycles), while it has a temperature sensitivity of up to − 0.015 ℃⁻¹ (in the range of 18–42 ℃), and a response time of 5 s between 20 ℃ and 45 ℃. Moreover, the bimodal sensor effectively addresses the issue of interference between pressure and temperature sensing, while also offering benefits such as breathability and self-cleaning. These features render it well suited for the monitoring of physiological signals in human subjects. Thus, the pressure–temperature bimodal tactile sensor has the potential to play a significant role in the development of motion monitoring systems, health monitoring systems, and human–computer interfaces.