Molecular evolution mechanism of flow-induced crystallization in polyphenylene sulfide

• PPS precursors have a critical temperature to change into crystals. • Shear deformation motivates the formation of precursors. • Pressure cannot drive the evolution of amorphous PPS into precursors. Microstructures play a significant role on the mechanical performance of materials. Based on the experimental characterization and molecular modeling techniques, this work assessed the influences on the mechanical properties of semi-crystalline 1-4 polyphenylene sulfide (PPS) from pressure and temperature. It was found that the shear deformation in the flow field is a key factor that induces the transformation from amorphous polymers to precursors. Though, pressure can accelerate the transition of precursors to crystals, proportion of precursors in the PPS is not observed under higher pressure. The understanding established in this work is helpful to identify optimal processing parameters during the manufacturing of PPS for target applications. Graphical Abstract .