Reversibility of Swelling, pH Sensitivity, Electroconductivity, and Mechanical Properties of Composites Based on Polyacrylic Acid Hydrogels and Conducting Polymers

Abstract

Composites based on polyacrylic acid gels as matrices and conducting polymers (polyaniline and polypyrrole) as functional components have been obtained. It has been shown that the dependence of the equilibrium degree of swelling on the pH medium for the matrices demonstrates its pronounced maximum at pH = 11. The reversibility of the processes of swelling/contraction for the matrices and composites over a wide variation of swelling medium acidities was studied and analyzed. The effect of the crosslinking degree of the matrix on the content of the conducting components in the composites was determined. The electric conductivity of the composites depended on the degree of crosslinking of the matrices, and the content of the conducting component was measured. Deformational characteristics at compression were measured for the matrices and composites prepared in block-shaped cylinders. It was proven that the formation of a rigid-chain conducting polymer phase in the composites led to an increase in the elastic modulus as compared with the one for the matrix gel, but it did not cause a noticeable decrease in elasticity. It was observed that the new composites were characterized by a combination of swelling capacity, pH sensitivity, and electroconductivity.