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 ...