Degradation Behavior of Poly(lactide-co-carbonate)s Controlled by Chain Sequences

Immortal copolymerization of lactide (LA) and 2-methyl-2-benzyloxycarbonyl-1,3-trimethylene carbonate (MBC) affords random, tapered, and diblock microstructured poly(lactide- co -carbonate)s. Subsequent debenzylation of these poly(LA- co -MBC)s by Pd/C catalytic hydrogenation gives poly(LA- co -MCC)s containing carboxylic acid, which show controlled degradation performance during in vitro hydrolytic degradation experiments. The degradation rates of poly(LA- co -MCC)s are proved for the first time to be affected significantly by lactide–carbonate linkages in the main chains, following the trend of lactide–carbonate unit (L–C/C–L)>carbonate–carbonate unit (C–C)>lactide–lactide unit (L–L). The resultant hydrolysis products are the precursors for synthesizing the corresponding monomers. Therefore, the degradable and recyclable materials are accomplished.