PolySTRAND Model of Flow-Induced Nucleation in Polymers

We develop a thermodynamic continuum-level model, polySTRAND, for flow-induced nucleation in polymers suitable for use in computational process modelling. The model's molecular origins ensure it accounts properly for flow and nucleation dynamics of polydisperse systems and can be extended to include effects of exhaustion of highly deformed chains and nucleus roughness. It captures variations with the key processing parameters, flow rate, temperature and molecular weight distribution. Under strong flow, long chains are over-represented within the nucleus, leading to super-exponential nucleation rate growth with shear rate as seen in experiments.