Separate Crystallization and Cocrystallization of Poly(L‐lactide) in the Presence of L‐Lactide‐Based Copolymers With Low Crystallizability, Poly(L‐lactide‐co‐glycolide) and Poly(L‐lactide‐co‐D‐lactide)

Abstract

Abstract Poly( L ‐lactide) (PLLA) and poly( L ‐lactide‐ co ‐glycolide) (78/22)0 [P(LLA‐GA)] were phase‐separated in PLLA/P(LLA‐GA) blends, forming independent domains and thence crystallizing separately. The crystallization of PLLA was not disturbed or delayed by the presence of P(LLA‐GA) and vice versa. PLLA and poly(L‐lactide‐ co ‐ D ‐lactide) (77/23) [P(LLA‐DLA)] were miscible in the PLLA/P(LLA‐DLA) blends, overall crystallization was delayed, and the growth of crystallites was disturbed in the presence of P(LLA‐DLA). In isothermal crystallization, the originally noncrystallizable P(LLA‐DLA) became crystallizable in the presence of PLLA, with which it cocrystallized. The disturbance effect on periodical lamella twisting of PLLA was larger for P(LLA‐GA) than for P(LLA‐DLA).