Effects of Branches on the Isothermal Crystallization of Copolymers Based on Poly(ϵ-caprolactone)

Abstract

A linear poly(ϵ-caprolactone), PCL, and grafted copolymers based on poly(2-hydroxyethylmethacrylate) and poly(ϵ-caprolactone) are used to study the effect of branches on PCL crystallization process. Copolymers are synthetized by a combination of ring opening polymerization and reversible addition fragmentation chain transfer polymerization, showing molar masses between 32 000 and 46 000 g mol −1 with M w /M n lower than 1.19. Isothermal crystallization kinetic is performed by Differential Scanning Calorimetry combining Avrami and Hoffman-Weeks theories. Regarding to Avrami parameters, copolymers exhibited half-life crystallization times 42 times higher than PCL homopolymer and two-dimensional crystallization growth. Copolymers’ growing rate values are 51 times higher than PCL values according to Hoffman-Weeks equation. These results suggest that interaction of grafted chains could hinder the rearrangement of PCL by reducing their final crystallization capacity.