NONLINEAR VISCOELASTICITY OF WORMLIKE MICELLES (AND OTHER REVERSIBLY BREAKABLE POLYMERS)

A model, previously introduced to describe the linear dynamics of entangled, reversibly breakable polymers, is extended to describe nonlinear effects. This extension of the model requires that (1) the nonlinear effects of a flow enter solely through its influence on polymer diffusion (not through any direct effect on the reaction rates for chain scission and recombination processes) and (2) the stress is dominated by polymer entropy contributions. With these assumptions, the viscoelastic functions are predicted to closely resemble those of the Doi-Edwards/Marrucci theory for monodisperse unbreakable polymers. The status of each assumption is discussed, with reference to recent experiments on viscoelastic solutions of polymer-like surfactant micelles. © 1990 American Chemical Society.