In situ ring-opening polymerization of poly(L-lactide)-graft-graphene oxide and its effect on the crystallization kinetics and morphology of biodegradable poly(L-lactide) at low loadings

Biodegradable poly(L-lactide) (PLLA) and graphene oxide (GO) nanocomposites were prepared by blending commercial PLLA with PLLA-g-GO at low loadings, which was synthesized via ring-opening polymerization using GO as the initiator and characterized with various techniques. Both the nonisothermal cold and melt crystallization behaviors and overall isothermal melt crystallization rates of PLLA have been enhanced significantly by PLLA-g-GO in the nanocomposites, relative to neat PLLA. PLLA-g-GO is more efficient than GO as a nucleating agent for the crystallization of PLLA, because PLLA is covalently grafted onto the surface of GO in PLLA-g-GO, which may provide better compatibility with the PLLA matrix and improve the nucleation ability.