Preparation and properties of intrinsically antimicrobial Nylon 6 containing Trifluoromethyl Thiazole ring via a capping strategy

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.