A novel route for the synthesis of processable conducting poly(m-aminophenol)

Polymerization of m-aminophenol (mAP) in aqueous NaOH solution was done chemically by using ammonium persulfate (APS) as an oxidative initiator. The product poly(m-aminophenol) (PmAP) was found to be highly soluble in aqueous sodium hydroxide, dimethyl sulfoxide (DMSO) and N,N-dimethyl formamide (DMF). From the intrinsic viscosity measurement, the optimum condition for the polymerization was established with 0.6 M NaOH medium with the ratio of monomer to oxidant as 1:1.5 (mol:mol). The polymer was characterized by FTIR and ¹H NMR spectroscopy, elemental (CHNS) and thermogravimetric (TGA) analyses. From the spectroscopic analysis the structure of the polymer was found to resemble that of hydroxy polyaniline as the polymer contains free –OH groups attached to o/m position in the phenyl ring. The elemental analysis of the polymer also confirmed the same. From TGA study, the polymer was found to be thermally stable. A freestanding film of poly(m-aminophenol) was cast in DMSO solution followed by solvent removal and drying of the film at 100 °C for 7–8 h in an oven. A dc conductivity of 4.8 × 10⁻⁴ S cm⁻¹ was obtained for the synthesized polymer film after doping with H₂SO₄ solution.