Synthesis and Chemical Recycling of a Polycarbonate Obtained by Anionic Ring-Opening Polymerization of a Bifunctional Cyclic Carbonate

This article deals with anionic ring-opening polymerization of a bifunctional cyclic carbonate consisting of both five- and six-membered rings (65CCP) and anionic depolymerization of the obtained polymer. Anionic ring-opening polymerization of 65CCP initiated with 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) afforded a polycarbonate remaining a five-membered cyclic carbonate group in the side chain (P(65CCP)) by the selective polymerization of the six-membered cyclic carbonate ring. The equilibrium nature of the polymerization allowed the efficient depolymerization of P(65CCP) by a catalytic amount of DBU to recover 65CCP in high yield, in which the five-membered cyclic carbonate ring also remained unreacted.