Molecular interpretation of the “stick–slip” defect of linear polymers

In this paper, we investigate the relationships between stick–slip defect and molecular slip at the wall for linear polymers. By considering Brochard–de Gennes slip model and molecular chain dynamics at the wall, we propose expressions for the critical shear stress and the critical shear rate at the onset of stick–slip. Moreover, we present a criterion of existence for the stick–slip defect, based on the molecular weight distribution. These various expressions are qualitatively validated by experimental data from the literature.