UNCOILING OF POLYELECTROLYTE MACROMOLECUL ES IN LONGITUDINAL FLOW

Uncoiling of the macromolecules of high-molecular-mass poly(2-vinylpyr idine), which occurs during longitudinal flow of semidilute acidic aqu eous solutions was studied. It was found that, as the concentration of acid is raised, the region of the transition to uncoiled state shifts to higher velocity gradients. The critical magnitudes of the gradient s, which correspond to the loss of stability of the macromolecular coi l, agree well with the predictions of the theory elaborating the dynam ics of semidilute polymer solutions.