Synthesis and characterization of biodegradable poly(ε-caprolactone-co-β-butyrolactone)-based polyurethane

Poly(epsilon-caprolactone-co-beta-butyrolactone) (PCLBL)-based polyurethane (PCLBL-PU) was synthesized and its tensile properties and hydrolytic degradability were investigated in an attempt to improve the degradability of poly(E-caprolactone)-based polyurethane (PCL-PU). PCLBL was synthesized by the ring-opening polymerization of epsilon-caprolactone (CL) and beta-butyrolactone (BL) with stannous octoate as a catalyst. The introduction of a small amount of BL units significantly decreased the crystallinity of PCLBL. The crystallinity of the soft segment of PCLBL-PU also decreased with increasing BL content, and thus its hydrolytic degradation rate was dramatically increased. PCLBL-PU polymerized with PCLBL containing 5.7 mol% of BL units showed very similar tensile properties to PCL-PU, but its hydrolytic degradation rate increased by 100% at 45 degrees C. (c) 2007 Elsevier Ltd. All rights reserved.