Multifunctional and sustainable DOPO-derivative coating for flame-retardant, antibacterial and UV-protective of polyamide 56 protective biomaterials

Polyamide 56 (PA56) biomaterial with excellent flame retardancy, antibacterial and UV-protective properties is potentially applied in the field of security and protection. Here, a green and sustainable multifunctional coating (DOPO-ATU) was developed, and then it was applied to modify PA56 fabric. The DOPO-ATU showed excellent flame retardancy to PA56 fabric. With 7.8 % weight gain, the coated PA56 fabric possessed a high LOI value of 30.1 % and a low damaged length of 11.1 cm without dripping. In cone calorimeter test, the peak heat release rate and average effective heat of combustion decreased by 20.5 % and 46.4 % versus pristine one, showing excellent fire safety. Further analysis proved that DOPO-ATU mainly acted in the gas-phase through the action of diluting non-combustible gases and quenching free radicals. In addition, the coated PA56 fabrics also displayed excellent antibacterial property and UV-protective properties. This work provides a cleaner and sustainable approach for preparing multifunctional coating for PA56 protective biomaterials.