Phenolic copolymer polyelectrolyte non-ionic homopolymer interactions: Thermodynamic and electrochemical studies in dimethylformamide water mixtures

p-Aminobenzoic acid/p-hydroxybenzoic acid/formaldehyde copolymer (I) was prepared and characterized. An interpolymer complex of copolymer (I) was prepared by adding stoichiometric amounts of a polyelectrolyte [poly(methacrylic acid)] and non-ionic homopolymers [poly(N-vinyl-2-pyrrolidone) and poly(ethylene oxide)]. The stability constant and related thermodynamic parameters (Delta H-0 and Delta S-0) were determined in DMF-H2O mixtures of different compositions using Osada's method. The stepwise degradation of the complex is explained on the basis of the relative stability of various interacting forces, particularly in media of varying dielectric constant. Electrochemical studies in the media substantiate the observations from thermodynamic studies.