Poly(D,L-lactic acid)/poly (epsilon-caprolactone) blend membranes: preparation and morphological characterisation

With the aim of exploring possible application of the concept of blend comp atibilisation into the field of biodegradable membranes, a study of the inf luence of random copolymer poly(D,L-lactide-co-epsilon-caprolactone) on the properties of corresponding homopolymer blends has been conducted. Blends of plain homopolymers and blends containing 5 and 10 wt% of a copolymer of suitable composition have been prepared in the melt and characterised for t heir molecular interactions using thermal, dynamic-mechanical, mechanical ( tensile tests) and morphological analyses. The blends are characterised by a good dispersion of the poly-epsilon-caprolactone (PCL) minor phase into t he poly(D,L-lactic acid) (PDLLA) matrix and better mechanical properties co mpared to plain PDLLA, and such characteristics further improve when adding the copolymer. Microporous blend membranes consisting of PDLLA and PCL wer e then prepared by a phase inversion method and characterised by scanning e lectron microscopy. The addition of compatibilising agent led to a highly h omogeneous structure, while in absence of compatibiliser a clear phase sepa ration occurred. (C) 2000 Kluwer Academic Publishers.