Solid-State Structure of Poly(lactide) Copolymers

Inferences from small-angle x-ray scattering, optical microscopy and DSC experiments were used to establish a model of the lamellar microstructure for random poly(L-lactide/meso-lactide) copolymers. From analysis of the SAXS data it was concluded that the copolymers contained significant interfibrillar regions whose concentration increased with comonomer content. Comparison of equilibrium melting points (derived using the Gibbs-Thomson approach) with those calculated from models for random copolymer melting leads to the proposal that R stereochemical defects are rejected from the crystalline regions.