Synthesis and Characterization of the Copolymer Poly(3-Poly(3-Hydroxybutyrate)-co-ε-Caprolactone) from Poly(3-Hydroxybutyrate) and Poly(ε-Caprolactone)

In the present work, the copolymer poly(3-hydroxybutyrate-co-epsilon-caprolactone), P(HB-co-CL), was prepared by transesterification reaction from PUB and PCL. Zirconium (IV) acetylacetonate was used as catalyst and the copolymers were obtained in a wide range of compositions of PHB/PCL (20/80, 50/50, 80/20). These copolymers were characterized by GPC, FT-IR, (1)H-NMR, (13)C-NMR, TG, and DSC. The copolymers had weight average molecular weight less than 24.000 Daltons. All the systems were thermally more stable than PHB, showing lower crystallinity than the homopolymers. These materials are good candidates to be used as biomaterials, in drug release matrices, or even as PHB/PCL blends compatibilizers.