ABOUT THE PROPER CHOICE OF VARIABLES TO DESCRIBE FLOW-INDUCED CRYSTALLIZATION IN POLYMER MELTS

摘要

The influence of flow on the crystallization of polymers is divided into four different regimes, using a molecular description of polymer rheology: (1) close-to equilibrium configurations, (2) orientated chains, (3) weak chain stretching, and (4) strong chain stretching where the chain conformation can be affected. It can be shown that these regimes correlate well with the different morphologies observed in flow induced crystallization experiments. An explanation for the change in nucleation dynamics can be given based on kinetic and/or ther-modynamic processes depending on the orientation and stretch of the polymer chains. The different morphologies are characterized by Minkowski function-als, and their development in time are described by the so-called Schneider rate equations.