Thermoreversible Gelation in Solutions of Associating Polymers. 2. Linear Dynamics

Abstract

Viscoelastic properties of reversible networks formed in solutions of associating polymers are considered theoretically in the Rouse−Zimm (unentangled) regime. It is shown that the dynamics is governed primarily by the network strand size and by the effective lifetime of reversible junctions. Both frequency and concentration dependencies of viscosity and dynamical moduli are considered. A novel model taking into account the possibility of multiple dissociation and recombination of the same pair of stickers is developed. It is shown that this effect gives rise to an increase of the apparent activation energy which is predicted to be substantially larger than the priming activation energy for dissociation of two stickers.