Chlorine substitution in poly(arylamine)s during synthesis and protonation in hydrochloric acid

Abstract

The effects of varying the oxidant monomer ratio in the polymerization of aniline, N-phenyl-p-phenylenediamine and N,N′-diphenylbenzidine in a hydrochloric acid solution of (NH4)2S2O8 were investigated. With the first two monomers, increasing the oxidant monomer ratio from 0·3 to 3 results in a substantial increase in polymer yield but the extent of covalent bond formation between chlorine and the polymer is also increased. In addition, differences in the N C and imine amine ratios, and in thermal stability, are evident in the polymers synthesized at different oxidant monomer ratios. The degree of polymerization of N,N′-diphenylbenzidine is low and it exhibits a very high susceptibility to chlorine substitution in the reaction mixture. A comparison of the extent of chlorine substitution is made among polymers synthesized in (NH4)2S2O8 HCl, and polyaniline base and aromatic amine monomers treated with HCl of the same concentration. © 1993.