Flow-Induced Crystallization of Polymers: Molecular and Thermodynamic Considerations

Abstract

Flow-induced crystallization (FIC) of polymers is a long-standing, industrial relevant, nonequilibrium thermodynamic challenge. Thanks to the development of in situ time and spatial resolved techniques like rheology and synchrotron radiation X-ray scattering, substantial progress on the understanding of FIC has been achieved in past 20 years. In this Perspective, we first discuss some recent modifications and improvements on early coarse-grained approaches like the coil–stretch transition model for shish formation and the entropic reduction model for the enhancement of nucleation rate. Then breaking out the two-phase model of classical nucleation theory, flow-induced coil–helix transition, density fluctuation or phase separation, and isotropic–nematic transition are considered as intermediate orders in FIC. Establishing flow morphology and phase diagrams is essential for revealing the nonequilibrium nature of FIC, which will serve as structural roadmap for the processing of high performance polymer products.