Cationic Ring-Opening Co- and Terpolymerizations of Lactic Acid-Derived 1,3-Dioxolan-4-ones with Oxiranes and Vinyl Ethers: Nonhomopolymerizable Monomer for Degradable Co- and Terpolymers

Lactic acid-derived 1,3-dioxolan-4-ones (DOLOs), which do not undergo cationic homopolymerization, were demonstrated to yield copolymers with oxiranes through a cationic copolymerization via frequent crossover reactions. Acetal and ester moieties were generated in the main chain of the copolymers via crossover reactions from DOLO to oxirane and from oxirane to DOLO, respectively, which is in contrast to the unsuccessful generation of hemiacetal ester moieties in the homopropagation of DOLO. In addition, the terpolymerization of DOLO, oxirane, and vinyl ether (VE) proceeded via crossover reactions, while copolymers could not be generated from VE and DOLO in the absence of oxirane. The obtained co- and terpolymers could be degraded under acidic conditions due to the acetal moieties in the main chain. The strategy devised in this study shows a promising avenue for employing plant-derived nonhomopolymerizable compounds as building blocks for the synthesis of degradable co- and terpolymers with general-purpose monomers.