LAUSR

Abstract Catechin (Cat) was added into polyurethane (PU) based on a tri-block copolymer of poly( l -lactic acid) and poly(e-caprolactone) (PLLA- b -PCL- b -PLLA) to improve the thermal stability of the final PU composite materials. The morphological, structural, mechanical and thermal properties of PU-Cat composites loaded with 1 wt%, 3 wt% and 5 wt% of Cat were investigated and designed as PU-Cat1, PU-Cat3 and PU-Cat5, respectively. Homogeneous films were obtained after the solvent casting process, but the higher amount of 5 wt% used in this work could not be successfully dispersed and produced some structural defects as were observed by scanning electron microscopy. Well dispersed Cat in PU-Cat1 and PU-Cat3 not only substantially improved the thermal stability due to the Cat antioxidant effect, but also allowed the crystallization of PCL and PLLA blocks in the final PU-Cat composites. Additionally, PU-Cat composite materials showed excellent stretchability for film production.