Studies on water soluble conducting polymer: Aniline initiated polymerization of m-aminobenzene sulfonic acid

The synthesis of poly(m-aminobenzene sulfonic acid) homopolymer (PABS), by aniline initiated polymerization of m-aminobenzene sulfonic acid using ammonium persulfate oxidation has been attempted. The water soluble polymer PABS thus synthesized was characterized by IR, UV, TG-DSC, 1H-NMR, SEM and ESR spectroscopic techniques. A co-ordinated IR and thermal analysis (TG, DSC) indicate that thermal desulfonation occurs preferentially in PABS–Na compared to PABS, commencing at 310°C and 370°C, respectively. The steric hindrance due to the large ortho substitution causes lowering of conductivity of PABS and its Na-salt which was found to be 5.4×10−5 S/cm and 2.4×10−6 S/cm, respectively. The ESR spectra show that the polymer to be strongly paramagnetic with a g value of 2.0013.