Thermostimulated crystallization of polylactide stereocomplex

A particular crystallization behavior of PIA stereocomplex was observed when the poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA) (50/50) was subjected to specific melting conditions. The effect of the holding temperature in the melt state of PLLA/PDLA samples on the nonisothermal melt crystallization process and on the structure have been investigated by means of DSC, and wide angle X-ray diffraction. In the moderate melting condition, residual ordered domains act as athermal nuclei and a single crystallization process via a predetermined nucleation mechanism was observed. The survived nuclei favor high temperature polymer crystallization, correspondingly, a high melting temperature (T-m(H)) of PLA stereocomplex, of 244.9 degrees C with the fusion enthalpy 87.0 J/g were obtained. Such a Tm result of PEA stereocomplex is much higher than that of the reported previously. (C) 2012 Elsevier B.V. All rights reserved.