Thermal Properties and Crystallinity of Grafted Copolymer Networks containing a Crystallizable Poly(ε-caprolactone) Crosslinker in an aqueous environment

Abstract

Here we introduce a multifunctional copolymer network system with adjustable thermomechanical properties, which is also capable to show a substantial water uptake and in this way should allow the additional alteration of the overall elastic properties besides the variation of the crosslinking density. The swelling capacity in water, the thermal properties as well as the crystallinity of a series of grafted copolymer networks named CLEG composed of water swellable poly(ethylene glycol) (PEG) side chains and crystallizable poly(ε-caprolactone) (PCL) segments acting as covalent crosslinker were explored in an aqueous environment. The water swelling capability of the CLEG polymer networks was found to increase from 120% to 240% with increasing weight content of PEG. In contrast to the dry state, where two well separated melting temperatures could be observed for all CLEG samples, in aqueous environment only one melting temperature slightly above 40 °C, was obtained, whereby the overall crystallinity after swelling with water was strongly related to the PCL content in the CLEG polymer networks.