CO<sub>2</sub>-Blown Nonisocyanate Polyurethane Foams
Ping Sen Choong, Yen Li Eunice Hui, Chen Chuan Lim
Abstract
Polyurethane (PU) foams are produced from toxic, petrochemical- and phosgene-derived isocyanates. Although nonisocyanate polyurethane (NIPU) has shown promise as a replacement for traditional PU, the synthesis of NIPU foams has not been widely studied due to the difficulties in replicating the foaming process of PU, in situ CO 2 production through the hydrolysis of isocyanates. Hereby, we report the synthesis of amine-CO 2 adducts and their CO 2 adsorption–desorption characteristics under different conditions. The results show that the amine-CO 2 adducts can exhibit up to 87% CO 2 desorption at 60 °C after aminolysis with cyclic carbonate. The amine-CO 2 adduct is used as both a foaming agent and a comonomer to obtain low-density foams (0.203–0.239 g·cm –3 ) after heating at 50–60 °C for 24–48 h. This marks the successful synthesis of in situ CO 2 -blown NIPU foams using an amine-CO 2 adduct.