Polymer crystallization, nucleation elongational flow

Transient molecular deformation and orientation in the systems subjected to flow deformation results in transient and orientation dependent crystal nucleation. Quasi steady-state kinetic theory of crystal nucleation is proposed for the polymer systems exhibiting transient molecular deformation controlled by the chain relaxation time. Access time of individual kinetic elements taking part in the nucleation process is much shorter than the chain relaxation time, and a quasi steady-state distribution of clusters is considered. TVansient term of the continuity equations for the distribution of the clusters scales with much shorter characteristic time of an individual segment motion, and the distribution approaches quasi steady state at any moment of the time scaled with the chain relaxation time. Quasi steady-state kinetic theory of nucleation in transient polymer systems can be used for elongation rates in a wide range 0 < esT C N. ... 

---