Electrical conductivity and counterion association of cationic polyacrylamide derivatives in aqueous solution

Equivalent electrical conductivity (Lambda) is reported for three series of cationic quaternary ammonium polyacrylamide derivatives with MeSO4-, Cl-, Br- and I- as counterions at 25 degrees C, the polyion equivalent concentra tion C ranging from 5.3 x 10(-4) to 6.4 x 10(-3) N and from 1.0 x 10-3 to 1 .4 x 10(-2) N. Equivalent electrical conductivity increases with decreasing polyion equivalent concentration, and the sequence of equivalent electrica l conductivity Lambda of polyelectrolytes for the same series with differen t counterions in the range of concentration investigated is: MeSO4- > Cl- > Br- > I-. The plots of the counterion-polyion interaction parameter f and degree of dissociation cw of polyelectrolyte versus the polyion equivalent concentration C show that the order of counterion associating or binding to polyions for the same polyelectrolyte series in the range of concentration studied is MeSO4- < Cl- < Br- < I-. The chemical structures of the polyion have much influence on the Lambda, f and alpha values of the polyelectroly tes. (C) 1999 Society of Chemical Industry.