The application of Avrami models to the overall crystallization data ruled out significant differences between nucleation mode and the crystal geometry of the linear and H-linked iPPs. Solid state 13 C NMR indicated that the H-links in the amorphous regions slows short segmental relaxations of the diene containing samples in this region compared to the linear ones. The wide difference in nucleation rates is correlated with differences in melt dynamics, as the longest more branched molecules may retain some order prior to crystallization from their melt state. The addition of extra entanglements in the linear chain by diene incorporation affects the spherulitic morphology and lamellar stacking. Dynamic mechanical analysis suggested minimal variation in the mechanical properties between the linear and H-linked polypropylenes.At higher concentrations of such defects, however, the crystallization process is slowed down and the overall crystallinity of the PET is reduced. A molecular dynamic analysis of the crystallization process that may occur in LLDPE has beenanbsp;...
|Title||:||Crystallization of Isotactic Poly(propylenes) with Enhanced Melt Strength|
|Author||:||Anindya Kumar Ghosal|
|Publisher||:||ProQuest - 2008|