Microscopic theory for the fast flow of polymer melts

Using the process of convective constraint release (CCR), a microscopic theory of nonlinear melt flow of entangled polymer melts was developed. The spurious maximum of shear stress as a function of shear rate was removed using a new formalism that simultaneously captures reptation, fluctuation motion of the chain, and Rouse motion of its tube. The results showed that local CCR was less effective in removing the stress maximum than in the case of polymer melts. The single-chain structure factor in shear flow probed by small angle neutron scattering (SANS) was predicted.