Synthesis and Enzymatic Degradation of Novel Polyurethanes Having Ester Bonds

Novel linear polyurethanes were synthesized by the reaction of methyl(S)-2,6-diisocyanatohexanoate (LDI) with bis(2-hydroxyethyl) terephthalate (BHET) and poly(ethylene glycol) (PEG). The polymers were obtained in relatively high yields (95~98%). Their number-average molecular weights determined by GPC were in the range from 2.1×104 to 2.4×104 and the polymers showed a glass-transition temperature at about −13°C by dynamic mechanical analysis. The polymers were rubber-like, elastic materials with high tensile strength of ca. 83 MPa. Enzymatic degradation of the polymers esulted in a weight loss of up to 98%. Moreover, numerous holes and hollow structures were observed on the surface of the degraded films by scanning electron microscopy.