A Nonlinear Network Viscoelastic Model

A nonlinear constitutive equation for polymer melts and concentrated solutions is derived from a Lodge‐Yamamoto type of network theory. The network junctions are postulated to move nonaffinely in a well‐defined manner. The functional form of the creation and destruction rates of junctions is assumed to depend on the average extension of the network strand and the absolute temperature in such a way to allow for the time‐temperature superposition principle. The theory shows good agreement with all data examined. The paper concludes with a strong flow problem (melt spinning). The results indicate the validity of the model in this flow regime.