Persistence length and plateau modulus of semiflexible entangled polymers in primitive chain network simulations

Abstract: The relationship between the plateau modulus (G_0) and the persistence length (L_p) of entangled semiflexible polymers is still uncertain. Some previous theoretical models have predicted that G_0 decreases with increasing L_p, while experiments indicated the opposite. In this study, we extend the primitive chain network (PCN) model to incorporate bending rigidity at the scale of the entanglement length, consistently with the coarse graining of the model. Simulations investigate the effects of rigidity (and of molecular weight) on chain conformation and relaxation modulus. Our results reveal a relationship described as G_0~L_p^2/3, indicating that G_0 increases with increasing L_p, consistently with experiments. It should be considered, however, that implicit in our simulations is the condition that the entanglement length is kept fixed with changing L_p.