Synthesis of processable conducting poly(m-aminophenol) having structure like keto derivative of polyaniline

Abstract

Poly(m-aminophenol) was synthesized chemically from m-aminophenol in aqueous hydrochloric acid using ammonium persulfate as an oxidizing agent. To get processable poly(m-aminophenol) the polymerization condition was optimized by varying HCl concentration and temperature. The synthesized polymers at lower HCl concentration were insoluble in organic solvents, but synthesized polymers at higher acid concentration were found to be soluble in aqueous sodium hydroxide, dimethyl formamide, dimethyl sulfoxide. The polymers were characterized by ultraviolet visible, proton magnetic resonance and Fourier transform infrared spectroscopy. X-ray diffraction analysis and elemental analysis of the synthesized polymers were also performed. DC electrical conductivity of the acid doped polymers was measured by Four-probe method. The spectral evidences clearly indicated that the ladder structure was formed in lower aqueous HCl concentration while open ring keto derivative of polyaniline was formed at higher HCl concentration. The polymer with open ring structure was better processabe and higher conductive in doped state than that of the other one. Difference of their properties like solubility, conductivity of the polymers synthesized at different condition was due to their structural difference.