Highly Enhanced Nucleating Effect of Melt‐Recrystallized Stereocomplex Crystallites on Poly(<scp>L</scp>‐lactic acid) Crystallization

Abstract

Abstract In the general processing temperature range of poly( L ‐lactic acid) (PLLA) articles (210–240 °C), PLLA/poly( D ‐lactic acid) (PDLA) stereocomplex (SC) crystallites melted just above the endset temperature of SC melting (228–238 °C) and recrystallized during cooling were found to act as the most effective nucleating agents for enhancing the crystallization of PLLA compared to partially melted SC crystallites (211–227 °C) or those melted far above the endset temperature of SC melting (240 and 250 °C) and recrystallized during cooling. The high nucleating effect of the SC crystallites melted in the temperature range of 228–238 °C was found to be caused by their smaller sizes or the larger number of SC crystallites per unit mass. The incorporation of such SC crystallites facilitates the processing of PLLA articles having high crystallinity and, therefore, high heat‐resistance in a shorter period to reduce the production cost. magnified image