Complexation behavior of polyelectolyte/polyelectolyte at weak neutralization degree: Study by several techniques

Abstract

The complexation of hydrolyzed polyacrylamide (AD37) and poly(4-vinylpyridine) (P4VP) in aqueous solution at 25 °C was studied by viscosity, conductivity and potentiometry measurements. The result shows, that intermolecular electrostatic association are favored by increasing the P4VP concentration. Thus, mixtures rich in P4VP are characterized by a high decrease in the viscosity due to interpolymer complete complexation AD37-P4VP, leading to the totally contraction or collapse of the polymer chains. So, strongest reduced viscosities, due to the inter-chain AD37 associations, are observed for the mixtures poor in P4VP. Potentiometric, viscometric and conductometirc measurements reveal that the complexation of the AD37 with the P4VP is insured by acid–base interaction between the carboxylate function and the partially hydrolyzed pyridinic nitrogen atoms.