Shape memory polymers (SMPs) with elevated switching temperatures and enduring thermal properties are highly desirable yet challenging in certain aerospace applications. In this study, high-temperature shape memory phthalonitrile resins (SMPNs) were developed using an end-capping strategy with the uniphthalonitrile (UPN) as the end-capping reagent to modulate the density of the cross-linked network. The resultant SMPNs exhibit a glass transition temperature (Tg) at approximately 300 °C, with a shape fixation rate of about 98 % and a shape recovery rate around 97 %. Importantly, these SMPNs also demonstrated exceptional thermal stability, with a thermal decomposition temperature exceeding 445 °C. Additionally, an oxyacetylene ablative test revealed the SMPNs' robust ablative resistance, as the linear ablation rate remained below 0.1 mm/s and the mass ablation rate was less than 0.1 g/s. The commendable shape memory performance and superior high-temperature resistance allowed the SMPNs to successfully undergo the shape recovery process when subjected to a butane flame. Furthermore, after a high-temperature annealing process, the SMPNs exhibited electrical conductivity due to graphitization, even possessing wave-absorbing properties within a specific frequency range. It is foreseeable that these multifunctional SMPNs will have extensive applications in the aerospace sector, given the advancement of smart structures.
Antibacterial nylon 6 exhibits excellent antibacterial properties, as well as good mechanical performance, wear resistance, and dyeing characteristics, making it widely applicable in various fields such as automotive, medical, apparel, and personal care industries, including medical sutures, food packaging films, and automotive interior materials. However, most of the reported antibacterial nylon 6 is prepared by doping antibacterial agents. Developing a simple strategy to synthesize intrinsically antimicrobial nylon 6 with superior antibacterial performance is of great significance, but also presents challenges. In this study, we propose a strategy for preparing intrinsically antimicrobial nylon 6 through a capping strategy. 2-Methyl-4-(trifluoromethyl)thiazole-5-carboxylic acid (TA), an antibacterial compound, was used as a capping agent. Through hydrolytic polymerization with caprolactam, we synthesized intrinsically antimicrobial nylon 6 with trifluoromethyl thiazole group. The results show that the prepared antibacterial nylon 6 possesses good mechanical properties and thermal stability, with a tensile strength exceeding 60 MPa and a thermal decomposition temperature above 390 °C. Furthermore, the addition of only 3 wt% TA completely eradicates E. coli and S. aureus , demonstrating excellent antibacterial efficacy.
危险品化学品经营许可证（带存储）