Design, synthesis and properties of environmentally friendly flame retardant and fluorinated waterborne polyurethane

Grafting modification of the alkyne-functionalized WPU was conducted via the Cu(I)-mediated cycloaddition with short-chain 2-azido acetic acid perfluorohexyl ethyl ester (Rf-N3). Environmentally friendly flame retardant and fluorinated WPU was fabricated based on char-forming mechanism of unreacted pendant alkyne groups at high temperatures, and its structure was confirmed. The influence of the grafting amount of Rf-N3 and alkyne groups on surface properties, thermal degradation and dynamic combustion properties of functionalized WPU films was studied. The results show that when the Rf-N3 content increases from 0% to 30%, the contact angle of WPU film increases from 61° to 108°, the char yield increases from 0.3% to 25% and the PHRR and SPR decrease from 700 kW/m2 to 523 kW/m2, and from 0.083 m2/s down to 0.0495 m2/s respectively. Moreover thermal degradation mechanism of WPU films was also proposed. ©, 2015, Chengdu University of Science and Technology. All right reserved.