Biodegradable stereocomplex polylactide having flexible ε-caprolactone unit

Stereocomplex formation between poly(L-lactide-co-ε-caprolactone) (PLLCL) and poly(D-lactide-co-ε-caprolactone) (PDLCL) is known to be disturbed when their molecular weights increase to >10⁵ g/mol. Here, Strong and biodegradable stereocomplexes of copolymers (S-PLCL) were studied using a supercritical fluid and co-solvent system. Mechanical properties such as tensile strength were ∼2.5 times increased due to high degree of stereocomplex than those of PLGA20. The addition of the flexible ε-caprolactone units to the polylactide increased its thermal stability which significantly enhanced 100% degree of stereocomplex after 2nd melt processing through DSC due to the increased mobillity of the polylactide's chains. The degradation behavior of resulting biodegradable S-PLCL showed slow degradation with increasing CL content in 0.13 M, pH 4.3 phosphate buffers.