STABILIZATION, REFORMATION AND MELTING OF POLY(L-LACTIDE) CRYSTALLITES

The large size of the crystallites in poly(L-lactide) and the low growth rate enable detailed time- and temperature-dependent X-ray scattering studies of the ordering processes to be carried out. A layer located intermediate between crystals and melt-like regions is observed which finally takes on crystalline order. Recrystallization processes during heating change the complete stack structure rather than the crystallites individually and produce voids in the stacks. Establishment of a new stable structure after a temperature jump in the melting range can be followed in time. DSC experiments indicate times of melting of the order of minutes.