Room temperature flexible isocyanate-free polyurethane foams

Abstract

We report the synthesis of sustainable isocyanate-free polyurethane foams. For the first time, polyhydroxyurethane (PHU) foams were synthesized at room temperature by high conversion step growth polymerization of cyclic carbonates and diamines. Trimethylolpropane tris-carbonate and polypropylene oxide bis-carbonate were copolymerized with EDR148 diamine with thiourea as catalyst. A poly(methylhydrogenosiloxane) was used as blowing agent to foam the NIPU by reaction with diamines. NIPU foams were characterized by scanning electron microscopy and by measurement of their swelling index and apparent density. The mechanical compression and the recovery of these NIPU foams were analyzed by dynamic mechanical analyses at room temperature. The thermal insulating capacities and thermal degradation mechanism were determined.