Exploring Nonlinear Rheological Behaviors in Entangled Semi-flexible Polymer Melts.

This study utilizes molecular dynamics simulation to investigate the complex dynamics of entangled semi-flexible polymer melts. The investigation reveals a significant stress overshoot phenomenon in the systems, demonstrating the intricate interplay between shear rates, chain orientation, and chain stretching dynamics. Additionally, the identification of metastable states, characterized by a dual-plateau phenomenon in the shear stress-strain curve at specific Rouse-Weissenberg number WiR, showcases the system's responsiveness to external perturbations and its transition to stable shear banding states. Moreover, the analysis of flow field deviations uncovers a progression of shear bands with increasing WiR, displaying distinct behaviors in the system's dynamics under different shear rates and chain lengths. These findings challenge established theoretical frameworks and advocate for refined modelling approaches in polymer rheology research. [ABSTRACT FROM AUTHOR]