A continuum model for flow-induced crystallization of polymer melts

摘要: A macroscopic, continuum model based on the Hamiltonian/Poisson Bracket formalism, combined with Avrami equation, is developed to simulate flow-induced crystallization of polymer melts in homogeneous flow fields under isothermal conditions. The predicts kinetics as well rheological and rheooptical behavior semicrystalline systems. amorphous phase modeled a modified Giesekus fluid crystalline approximated collection multibead rigid rods that grow orient field. two phases are coupled crystallinity via dissipative Poisson brackets. input parameters can be obtained from experiments. Orders magnitude reduction induction times enhancements rates predicted occur flow. Critical deformation captured above which sharply decrease. Calculations show increases stiffness strain hardening system dramatic stresses during crystallization. Moreover, for temperature range studied, hydrodynamic forces dominate undercooling effect regime high rates. simulations also predict more rapid following cessation relative quiescent