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.