Synthesis of a reactive polyester bearing α,β-unsaturated ketone groups by anionic alternating copolymerization of epoxide and bicyclic bis(γ-butyrolactone) bearing isopropenyl group

摘要

A novel bicyclic bis(γ-butyrolactone), 2,8-dioxa-1- isopropenylbicyclo[3.3.0]octane-3,7-dione (2), was successfully synthesized by the reaction of 1,2,3-propanetricarboxylic acid and methacrylic anhydride at 140 °C in the presence of N,N-dimethyl-4-aminopyridine and CuCl_2. Anionic ring-opening copolymerization of 2 with glycidyl phenyl ether (GPE) using PPh_3 as an initiator proceeded in a 1:1 alternating manner to give the corresponding polyester 3 bearing α,β-unsaturated ketone groups in the side chains. Prolongation of polymerization time resulted in the production of an insoluble networked copolymer due to reactions of the α,β-unsaturated ketone groups in the side chains. In order to demonstrate the potential of the copolymer 3 as a reactive polymer, Michael addition of thiols to the α,β-unsaturated ketone groups in the side chains was performed.