Synthesis and degradation of poly (2-hydroxyethyl methacrylate)-graft-poly (ε-caprolactone) copolymers

Poly (epsilon-caprolactone) macromonomers carrying a methacryloyl end groups were synthesized using different lanthanide derivatives as catalysts, and characterized by SEC and H-1 NMR. Hydrophilic-hydrophobic copolymers from macromonomers and 2-hydroxyethyl methacrylate (HEMA) were obtained by solution free radical polymerization. Depending on the feed ratio of the two components, different copolymer structures were obtained. The expected graft structure of the copolymers was confirmed by H-1 NMR. Thermal properties of the copolymers were determined by DSC and TGA. Hydrolytic and enzymatic degradations of the materials were performed. Poly (2-hydroxyethyl methacrylate)-graft-poly (epsilon-caprolactone) copolymers containing 33 or 50% of PCL showed only a weak hydrolysis of the powders and no enzymatic degradation. After 49 days, only PCL with a HEMA motive to its chain-end was entirely degraded by the Lipase PS from Pseudomonas cepacia. (C) 2003 Elsevier Ltd. All rights reserved.