Interpolyelectrolyte complexation of sulfonate-containing aromatic polyamide in aqueous solutions: the influence of the nature of the polybases on the composition of the formed products

Complexation in aqueous solutions of poly-4,4'-(2,2'-disulfonate sodium) diphenyleneisophthalamide and polyamines series: polyethylenimine, poly-N-(2-aminoethylacrylamide) and polyethylenepolyamine was studied. It is shown that as a result of macromolecular reactions, interpolyelectrolyte complexes are formed, stabilized mainly by electrostatic forces. To characterize the composition formed interpolyelectrolyte complexes used the ratio of sulfonate and amino groups interacting polyelectrolytes. Conductometric and potentiometric methods it has been established that in the investigated system, the mixing of the components of complexes are formed with ratio of the sulphonate and amino groups ~0.8. An increase in the degree of ionization of participating in reactions of complex formation of polyamines leads to higher recorded values of up to 0.90–0.95. It was found that interpolyelectrolyte complexes with an average particle size of ~42.1 nm are formed with the optimal composition of the interpolymer system. In an acidic medium, the average particle size is ~29.5 nm. Materials were obtained on the basis of the studied systems with high strength characteristics. The tensile strength of the film samples is 65–84 MPa with a relative elongation of 20–65%. It is shown that synthesized materials are characterized by high regulated hydrophilicity and selective sorption capacity in relation to water in comparison with organic solvents. The composition of interpolyelectrolyte complexes is one of the main instruments for regulating the physicochemical properties of the materials obtained. The results of these studies allow us to consider interpolyelectrolyte complexes based on poly-4,4'-(2,2'-disulfonate sodium) diphenyleneisophthalamide as promising for use in hydrophilic pervaporation processes.