SUPERTOUGH POLY(LACTIDE)S

Semi-crystalline and amorphous copolymers of lactide and glycolide wer e rubber modified with degradable rubbers based on epsilon-caprolacton e. The influence of crystallinity of the matrix, type of rubber and ch ain architecture on the impact resistance of the resulting materials w as investigated. With a poly(L-lactide-co-epsilon-caprolactone) rubber semi-crystalline poly(lactide)s could be impact modified to a greater extent than amorphous non-crystallizable lactide matrices. Poly(trime thylene carbonate-co-epsilon-caprolactone) was used in blends and line ar and star-shaped block copolymers which yield supertough materials t hat do not break in Izod notched impact testing. Rubber content appear s critical around 20 weight percent, where a sharp transition is obser ved.