Abstract Polymers are large molecules composed of repeating structural units, known as monomers. Plasticization is a widely recognized approach for enhancing the flexibility, processability, and mechanical performance of polymers. Recently, ionic liquids have garnered attention as promising plasticizers for various polymers, owing to their distinctive physicochemical properties. In this mini-review, a variety of ionic liquids utilized as plasticizers and numerous polymers used along with ionic liquids are categorized. Furthermore, the preparation processes and physicochemical properties of ionic liquid-plasticized polymers are succinctly explained. This review also underlines proposed applications of ionic liquid-plasticized polymers. In conclusion, numerous studies have revealed that the addition of ionic liquids decreases the glass transition temperature, degree of crystallinity, and degradation temperature of polymers. This reduction is ascribed to the plasticizing effect of ionic liquids. The proposed applications of ionic liquid-plasticized polymers align with global trends toward multifunctionality, sustainability, and innovative materials.

Abstract Silicone rubber is renowned for its excellent insulating properties. Enhancing its thermal conductivity can significantly improve its performance, making it more suitable for the demanding conditions of operational transformers. Adding liquid silicone rubber (ALSR) with high-performance fillers modified by coupling agents effectively enhances its thermal conductivity. This study used molecular dynamics simulations to construct Al2O3/ALSR models with unmodified and 3-aminopropyltriethoxysilane (KH550) silane coupling agent-modified alumina at grafting rates of 5% and 10%. The effects of different grafting rates of surface-modified Al2O3 on the thermodynamic properties and microstructure of silicone rubber composites were analyzed. The study found that the modification with the KH550 silane coupling agent significantly enhanced the thermodynamic properties of Al2O3/ALSR composites. Compared to the model without a grafting coupling agent, the thermal conductivity of the composite materials with grafting rates of 5% and 10%, respectively, increased by 97.91% and 127.75%. Simultaneously, excessive content of silane coupling agents can lead to instability in the molecular interface structure, resulting in a decline in the composite materials’ thermal stability and mechanical properties. By examining the free volume and mean square displacement of the composite materials, it is observed that the surface modification of Al2O3 with the silane coupling agent KH-550 restricts the mobility of silicone rubber molecular chains. However, as the grafting rate increases, this hindering effect diminishes, consequently reducing the interfacial adhesion of Al2O3/ALSR.

Abstract Janus nanofiber membrane films (JNMF) are known for their asymmetric properties. This includes protecting the wound from external liquid contamination and efficiently soaking up excess fluids. The morphology of these membranes was meticulously analyzed using scanning electron microscopy, while their water absorption potential, water contact angle, and crucial mechanical properties were rigorously tested. With increasing calcium silicate (CS) concentration in JNMF, the tensile strain first increased and then decreased. When CS content was 15%, its peak value was 38.28%, indicating the best performance. In vitro tests confirmed that JNMF loaded with Si4+ effectively promote cell adhesion, multiplication, and directional migration. In vivo studies have shown that JNMF possesses anti-inflammatory properties, promotes angiogenesis, and facilitates the regeneration of epidermal tissue. Immunohistochemical staining underscored the JNMF ability to accelerate wound healing by upregulating CD31 and α-SMA expression. As a result, JNMF presents itself as a promising material for the treatment of severe burn wounds.

Abstract Bacterial keratitis is a common infectious eye disease. Conventional antibiotic eye drops are becoming less effective due to antibiotic resistance. Herein, we design an innovative transition metal ion-based nano-delivery system for the treatment of bacterial keratitis. Zinc (Zn 2+ )–gallic acid–poly- l -lysine nanocomplex (ZGNC) is designed by coordination interaction. ZGNC is stable in a physiological environment and can be dissociated in an acidic infected microenvironment. The positively charged ZGNC can be effectively adhered onto bacterial cells and subsequently realizes in situ release of Zn 2+ , leading to much better bactericidal effect than free Zn 2+ . Importantly, ZGNC maintains excellent bactericidal activity in a protein-rich environment, while free Zn 2+ is completely invalid to eradicate bacteria in a protein-rich environment. The in vivo bactericidal ability of ZGNC is further confirmed in a murine bacterial keratitis model. This research provides a promising method to treat bacterial keratitis by a transition metal ion-based nano-delivery system.

Abstract The use of adhesive joints in marine environments for extended periods and under adverse environmental conditions leads to accelerated adhesive degradation. Therefore, this study aims to perform a dual analysis, both experimental and FEM, based on steel–polyurethane–steel adhesive joints to evaluate their fracture behaviour in Mode I under degradation conditions caused by accelerated polymer aging, due to the combined effects of moisture (seawater immersion) and high temperature (50°C). Experimental tests provided insights into the moisture concentration profiles within polyurethane, determining its critical concentration (0.61%) and diffusion coefficient (5.105 × 10 −13 m 2 ·s −1 ). Additionally, the variation curve of fracture energy versus elongation and the cohesive behaviour law of polyurethane were obtained (maximum stress of 0.32 MPa with a deformation of 0.02 mm). These experimental results enabled the development of an FEM analysis of the polyurethane adhesive joint, allowing for the simulation of the polyurethane–steel interface behaviour under adverse environmental conditions and constant Mode I loading. This approach makes it possible to predict both the failure moment and failure mode of the joint.

Abstract In this study, the utilization of sepiolite (SEP), renowned for its remarkable water absorption capacity, in a one-component silicone potting adhesive was explored to evaluate its impact on the efficacy of tunnel crack injection adhesive. Initially, SEP underwent high-temperature calcination, and X-ray diffraction and thermogravimetric tests were conducted to analyze the influence of calcination on its crystal structure and water-absorption capacity, respectively. Following this, various coupling agents were employed to modify the SEP, and their respective impacts on the performance of the tunnel crack-filling adhesive were investigated. The outcomes revealed that KH550 exhibited the most effective modification. Subsequent analysis delved into the effect of varying the dosage of KH550 on adhesive performance, demonstrating optimal cost-effectiveness at a dosage of 2 phr. Furthermore, a comparative assessment of the adhesive’s performance in wet and dry interfaces revealed that the addition of SEP resulted in comparable bond strength between wet and dry interfaces, indicating minimal influence from the wet interface.

Abstract To investigate the impact and flexure behavior of carbon fiber reinforced polymers/aluminum-honeycomb sandwich panel, low-velocity impact, compression-after-impact (CAI), and three-point flexure tests are conducted carefully. Four kinds of carbon fiber prepregs are selected to make face sheets by hot press preparation. Further, the digital image correlation technique is employed to record the damage evolution under the compression and flexure loads. The results show that the sandwich structure has two stages of impact response, first, the brittle behavior of the upper panel, and then the resistance of both sandwich and lower panel to absorb energy. In the CAI test, the failure position shifts from the ends to the impact cross section, and the compressive strength can be reduced by 40% only by 1 J impact. The strength of in-plane flexure is at least twice greater than that of out-of-plane flexure. The damage and deformation of in-plane flexure are found mainly in the upper panel and sandwich core, and the lower panel bends significantly.

Graphical abstract Polyglycolide-based polyurethane was synthesized via chain extension reaction. As the hard segment content increases, its thermal stability and mechanical properties are improved; and the weight loss rate in PBS solution is reduced.

Abstract To investigate the potential applications of bio-based epoxy resins across diverse fields, this study synthesized a bio-based epoxy resin using itaconic acid (EIA) as the precursor material and compared its thermal, mechanical, and electrical properties with those of epoxy acrylate (EA). The findings indicate that the glass transition temperature and the 5% thermal decomposition temperature of the EIA-cured system are higher than those of EA. The breakdown field strength of the EIA-cured system is slightly higher than that of EA (35.58 kV·mm−1), suggesting that EIA exhibits stronger electrical properties compared to EA. Mechanical property tests demonstrate that the tensile strength, elongation at the fracture point, and Shore hardness of the EIA-cured system are superior to those of EA. In conclusion, EIA, serving as a matrix resin, is influenced by cross-linking density and intramolecular ester bonding and exhibits close electrical strength but superior mechanical, thermal, and degradation properties than EA.

Abstract With the help of bolted joints to assemble a complex structure, carbon fiber reinforced polymer composite (CFRP) is widely used in various fields. However, stress concentration around holes at the bolted joints leads to a decrease in bearing capacity. Composites often result in mechanical degradation subjected to a complex hydrothermal environment. Therefore, to study the tensile behavior of CFRP bolted joints subjected to hydrothermal aging, the tensile tests are conducted carefully. The influence of aging time and temperature on tensile strength is investigated based on the response history, strain contour, and failure morphology. The failure mechanism is revealed via digital image correlation technology. Finally, the experimental results demonstrate that the bearing capacity of the structure in hydrothermal aging decreases significantly. Compared with the unaged specimens, the peak force of the specimens aged for 6 weeks at 25°C and 65°C is reduced by 22.79% and 35.63%, respectively. Under both the unaged and aged, the same bearing failure is found in the tensile tests of CFRP single-bolt single-lap joints.