Radical ring-opening polymerization towards degradable polymer as chain extender for polylactic acid

Degradable polymer materials have gained considerable research efforts nowadays. However, widely utilized polymeric chain extenders for degradable polymer materials are mainly nondegradable, where their degradability is ignored. Here, degradable polymeric chain extender for polylactic acid is designed via versatile radical ring-opening polymerization (rROP), by facilely incorporating of labile ester group into main chain of polymeric chain extender. Through reversible addition-fragmentation chain transfer rROP of cyclic ketene acetal as comonomer, a series of epoxy group-containing degradable polymers are synthesized. Further systematic investigations on these degradable polymeric chain extenders for polylactic acid are carried out, which enable polylactic acid with improved viscosity and modulus properties. This work therefore expands the molecular design of degradable polymeric chain extender and the application fields of degradable polymers via rROP, which might cause inspirations to the fields of polymer chemistry, processing and engineering.