We have studied structure formation process during crystallization of poly(L-lactic acid) / Poly(D-lactic acid) blends (PLLA / PDLA) under shear flow using time resolved polarized optical microscopy, small and wide angle x-ray scattering and viscoelastic measurements.  In order to improve mechanical properties and crystallinity, the shish-kebabs formation process was focused on.  We could observe the acceleration of crystal growth rate and morphological change, stacked lamella structure, by shear flow, with optical micrographs and x-ray scattering profiles.  The onset time of crystal growth decreased with increasing shear rate and strain.  Furthermore; the longest relaxation time, the reptaion time, was estimated from the viscoelastic measurements.  In our experimental conditions, the shear rate is much smaller than the inverse of reptation time, and then the stretching and disentanglements of PLLA/PDLA chains did not occur.  In this condition, the local orientation could behave nucleating agents of both spherulites and shish-kebabs.

Stereocomplex crystallization process under shear flow of poly(L-lactic acid)/poly(D-lactic acid) blends

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.