Synthesis and characterization of double crystalline cyclic diblock copolymers of poly(ε-caprolactone) and poly(l(d)-lactide) (c(PCL-b- PL(D)LA))

Abstract

The synthesis of symmetric cyclo poly(ε-caprolactone)–block–poly(l(d)-lactide) (c(PCL–b–PL(D)LA)) by combining ring-opening polymerization of ε-caprolactone and lactides and subsequent click chemistry reaction of the linear precursors containing antagonist functionalities is presented. The two blocks can sequentially crystallize and self-assemble into double crystalline spherulitic superstructures. The cyclic chain topology significantly affects both the nucleation and the crystallization of each constituent, as gathered from a comparison of the behavior of linear precursors and cyclic block copolymers. The stereochemistry of the PLA block does not have a significant effect on the nonisothermal crystallization of both linear and cyclo PCL-b-PDLA and PCL-b-PLLA copolymers.