Polymers最新文献

Poly(vinyl butyral) (PVB) displays exceptional adhesion to glass surfaces and high transparency, serving as the dominant interlayer material in laminated glass composites. This study systematically investigates PVB particulate composites, focusing on the interactions between a plasticized PVB matrix and silicate or silica dispersions as reinforcements. PVB composites reinforced with glass flakes, glass fibers, and fumed silica at loadings of 2, 5, and 8 vol% were produced and characterized. Optical microscopy and thermogravimetric analysis were employed to evaluate filler incorporation and dispersion under melt mixing conditions representative of industrial extrusion. Transparency measurements assessed the optical clarity of the composites, while ATR-FTIR was used to identify chemical interactions between PVB and the fillers. Regarding mechanical performance, fumed silica increased tensile strength up to 29 MPa and reduced displacement at fracture by 120%, while high-aspect-ratio flakes and silane-treated fibers only significantly increased composite stiffness. Impact resistance was additionally evaluated, revealing a significant enhancement upon the addition of fibrous reinforcements, especially when silane-treated fibers were used. Fumed silica increased the thermal stability of PVB by 7 °C and reduced water uptake to approximately 4.5%, in contrast to glass flakes, which increased water absorption reaching up to 8-11%. Lastly, the processability of composites was monitored, showing a progressive decrease with increasing filler content for all reinforcements. Overall, this work provides a comprehensive assessment of PVB-silicate/silica interfacial interactions and highlights the design of PVB composites suitable for advanced applications or the upcycling of secondary recycled PVB grades.

This study presents a promising strategy for the fabrication of a novel chitosan-based nanogel-in-oil system by integrating the development of a water-in-oil (W/O) microemulsion containing chitosan as a template, followed by crosslinking with genipin, a natural crosslinking agent, via emulsion crosslinking. To develop the W/O microemulsion template, nanometer-sized internal aqueous droplets were successfully formed in cottonseed oil, a vegetable oil, using a blend of nonionic surfactants, polysorbate 80 and sorbitan monooleate. A pseudoternary phase diagram was constructed to investigate the phase behavior of systems composed of chitosan solution, mixed surfactant, and cottonseed oil. Compositions falling within the monophasic region were selected for further formulation optimization. The microemulsions were characterized for droplet size, size distribution, electrical conductivity, and viscosity. The optimal microemulsion exhibited W/O characteristics with the lowest viscosity. Dynamic light scattering (DLS) analysis confirmed the presence of uniformly distributed nanometer-sized droplets, as evidenced by a Z-average diameter of 92.9 ± 2.3 nm and a PDI of 0.100 ± 0.072. The microemulsion system demonstrated physical stability, as confirmed by centrifugal testing. Crosslinking of chitosan with genipin was monitored by fluorescence intensity measurements of the crosslinking products. Fourier transform infrared spectroscopy further confirmed the formation of genipin-crosslinked chitosan structure. DLS and transmission electron microscopy revealed that the nanogels possessed nanoscale dimensions and discrete spherical morphologies. Overall, this approach demonstrates a viable route for producing a nanogel-in-oil system by combining microemulsion templating with emulsion crosslinking.

This paper aims to investigate the effects of the co-pyrolytic product produced from the co-pyrolysis of waste cooking oil (WCO) and polypropylene (PP) on pure bitumen by using some physical and rheological tests. To reach this goal, the product was obtained by producing from the co-pyrolysis of WCO and PP at distinct conditions. Different pyrolytic products with different structural properties can be obtained from the co-pyrolysis of various materials at different pyrolysis conditions. It was not found any study in which bitumen was modified with the co-pyrolytic product produced from the co-pyrolysis of WCO and PP materials at specified blending ratios and conditions, as described in this paper. For this reason, this paper investigates the effects of this co-pyrolytic product as an additive on bitumen in order to improve some of the rheological and physical properties of bitumen and to overcome some problems for the first time. The mixture ratio was determined as 1:2 (WCO:PP). PG 64-22 neat bitumen was modified with this co-pyrolytic product, and some features of the bituminous binders were detected by using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), penetration, softening point, dynamic shear rheometer (DSR), rotational viscometer (RV), a rolling thin film oven test (RTFOT), a pressurized aging vessel (PAV), a bending beam rheometer (BBR), storage stability, and scanning electron microscopy (SEM) tests. From the FTIR results of the modified binders, it was found that the intensity of the peak around 2357.69 cm^-1 increased with the addition of this pyrolytic product. This pyrolytic additive hardened the pure bitumen's consistency, increased its viscosity, improved its resistance against rutting deformations, and enhanced its high-temperature performance. It can be said that PG 64-22 pure bitumen can easily be modified with this pyrolytic product at the conditions described in this study. Additionally, this co-pyrolytic product improved the high-temperature performance grade (PG) of pure bitumen from PG 64 to PG 76 when it was used at 5% of the weight of neat bitumen. The findings demonstrated that the modified bituminous binders containing 3% and 5% co-pyrolytic product had suitable storage stabilities.

Carbon fiber-reinforced thermoplastic composites (CFRTP) are widely used in automotive, aerospace, and other industries due to their lightweight, high specific strength, recyclability, and superior thermal properties. However, their non-homogeneity and anisotropy present challenging machining characteristics, often leading to damage that deteriorates component performance. It is imperative to conduct numerical simulation and experimental studies on CFRTP to systematically analyze the relationship between cutting mechanisms and the surface integrity of CFRTP. This study aimed to establish an innovative three-dimensional micro-scale cutting numerical model that integrates the differentiated constitutive behaviors and damage criteria of carbon fibers, matrices, and fiber-matrix interfaces-enabling precise characterization of micro-scale damage evolution during cutting. By combining simulation with experimental verification, it unveils the material removal mechanisms and processing damage causes of CF/PEEK, and further pioneers the quantification of the gradient correlation between fiber orientations (0°, 45°, 90°, and 135°) and fracture modes, cutting forces, and surface integrity, thereby addressing the gap of micro-mechanism and quantitative analysis in CFRTP machining. The micro-scale damage mechanisms revealed by the model directly reflect the intrinsic response of individual fibers in the tow, and the collective effect of these micro-behaviors determines the macro-scale machining performance observed in the experiments. A right-angle cutting experiment was conducted to validate the accuracy of the micro-scale numerical model. The mechanisms of fiber fracture, damage patterns, and chip morphology were systematically compared. The experimental results demonstrate good agreement with the outcomes of the numerical simulations. This study aims to bridge the gap between theoretical understanding and practical application of the cutting mechanisms in CFRTP, providing valuable insights for advancements in manufacturing processes.

Polymer functionalization is rapidly emerging as a transformative strategy for enhancing nanocatalysts by reprogramming the catalytic interface, rather than simply modifying the active phase. This approach leverages the unique tunability of polymers through their chemistry, thickness, permeability, charge density, and ionic/electronic conductivity to stabilize nanophases, regulate local microenvironments, and manage mass transport. These properties significantly improve catalytic activity, selectivity, and long-term durability. This review provides an in-depth examination of key construction strategies for polymer-functionalized nanocatalysts, categorizing them into six primary platforms: neutral functional polymers, ionomers/polyelectrolytes, conductive polymers, crosslinked networks/hydrogels, hybrid polymers, and framework polymers. Additionally, we explore recent advances in electrocatalysis, photocatalysis, and thermocatalysis, addressing challenges such as the trade-off between protection and accessibility, polymer stability under extreme conditions, and the need for standardized reporting of polymer descriptors. By framing polymers as programmable interfacial materials, this review highlights their potential to unlock significant improvements in catalytic performance across various catalytic systems.

Bamboo, a fast-growing biomass material with excellent mechanical properties, is widely used in furniture and construction. However, its susceptibility to moisture, cracking, and aging limits its durability. While acrylic resins offer good weather and water resistance, the relationship between resin formulation and the performance of bamboo remains unclear. This study developed a novel water-based styrene-acrylic resin tailored for bamboo, systematically investigating the relationships between resin formulation, coating structure, and performance. Results show that vinyltriethoxysilane-modified styrene-acrylic resin outperforms hydroxypropyl-acrylate-modified and unmodified styrene-acrylic. At a 10% dosage of vinyltriethoxysilane, the Zeta potential reached -24.2 mV, indicating enhanced emulsion stability. The coated bamboo exhibited a water contact angle of 100.56 ± 1.11°, a pencil hardness of 4H, and an adhesion grade of 1, significantly improving its waterproofing, hardness, and bonding strength. UV aging tests confirmed improved anti-aging performance, with optimal results at 10% dosage: color difference (ΔE) of 3.00 ± 1.81, dimensional change rate of 0.76 ± 0.22%, and gloss retention of 78%. This study also pioneers research on contact angle hysteresis for coated bamboo. The findings provide theoretical and technical support for developing high-performance bamboo coatings and durable outdoor bamboo products.

The thioacetamide derivative (TD)-composite preservation system (TDCPS) exhibits superior preservation effects on natural rubber (NR) latex and significantly enhances its vulcanization efficiency and mechanical properties. This study assessed TDCPS for NR, with a particular focus on its effects in promoting vulcanization. The TD containing both pyridine and thioamide groups was evaluated against other additives, namely thione accelerator ETU, pyridine 3-HP, and thioacetamide TAA. The results indicated that TD significantly reduced vulcanization time and enhanced efficiency, surpassing the moderate effects of ETU and 3-HP, as well as the minimal activity of TAA. Furthermore, TD and 3-HP demonstrated a synergistic effect in enhancing the properties of vulcanized NR, including elongation stress, tensile strength, tear resistance, and hardness, with TD achieving more rapid and complete vulcanization at higher dosages. Both TD and 3-HP increased the energy storage modulus of raw NR, thereby enhancing rigidity, while maintaining low loss factor values. The superior performance of TD is attributed to the synergistic interaction of its pyridine and thioamide groups, which optimize vulcanization kinetics and mechanical integrity. These findings underscore TD's potential as an efficient vulcanization promoter for NR.

We investigated the high-temperature tensile and creep properties of highly strong heat-elongated polypropylene (elongated PP) before and after long annealing for 21 days at a high temperature of 120 °C. Despite the thermal deterioration caused by the long annealing, the elongated PP exhibited high tensile strength. The yield stress values of the elongated and long-annealed (LA)-elongated PP obtained from engineering stress-strain curves were 60 MPa and 102 MPa, respectively, at 120 °C, whereas that of the unelongated PP was 8 MPa. Due to the suppression of crystalline chain motion at high temperature caused by the presence of crystalline fibrils connected to lamellae, as indicated by the high elastic modulus observed using a dynamic mechanical analyzer, the elongated PP also exhibited excellent high-temperature creep properties despite thermal deterioration. Small-angle X-ray scattering and DSC measurements revealed that lamellae were fragmented in the elongated PP, while the fragmentation of lamellae was suppressed in the LA-elongated PP during tensile stretching and creep. These characteristic deformation behaviors might also provide excellent high-temperature properties. The excellent high-temperature properties of the elongated PP are promising for industrial applications that require resistance to high temperatures.

Chronic wounds and implanted medical devices remain highly vulnerable to biofilm-associated infections, which resist conventional antibiotics and immune clearance. Synthetic antimicrobial peptides (AMPs) have emerged as promising alternatives, offering tunable sequences, short lengths for cost-effective synthesis, and functional modifications that enhance stability and antibiofilm potency. Hydrogels provide an optimal delivery matrix by enabling localized AMP release, maintaining a moist wound environment, and supporting stimuli-responsive or sustained therapeutic action. This review highlights recent advances in peptide engineering strategies-including rational sequence design, chemical modifications, and self-assembling nanostructures-alongside hydrogel integration approaches ranging from physical entrapment to covalent tethering and infection-triggered release systems. Mechanistic insights into antibiofilm activity are discussed, supported by in vitro, ex vivo, and in vivo evaluation models. Beyond antimicrobial efficacy, multifunctional AMP-hydrogel systems can deliver complementary benefits such as hemostasis, anti-inflammation, or enzymatic biofilm dispersal, further accelerating tissue repair. Despite significant progress, translational challenges remain, including peptide stability, manufacturing costs, regulatory hurdles, and host safety. Future directions point toward AI-driven peptide design, programmable hydrogels, and point-of-care integration to realize safe, effective, and multifunctional AMP-hydrogel therapies for chronic wound management and biofilm eradication.

The effective utilization of biomass components in the pre-hydrolysis liquor (PHL) of lignocellulose is a crucial way for traditional pulp and paper mills converting into biomass refining facilities. In the present work, separation technologies are summarized and reviewed-including acidification, ethanol precipitation, flocculation and coagulation, adsorption, solvent extraction, enzyme treatment, and oxidation-with regard to component separation and impurity removal. The utilization of hemicelluloses from PHL for the production of furfural, adhesive and biofuel, as well as the application of lignin separated from PHL and the full components utilization of PHL without separation is reviewed and analyzed.