p-Toluenesulfonic acid catalytic polymerization of EDOT without oxidants

Abstract In this paper, a convenient oxidants free acid polymerization method is developed to synthesize poly(3,4-ethylenedioxythiophene) (PEDOT). p -Toluenesulfonic acid ( p -TsOH) is served as catalyst to direct polymerization of EDOT. The electron spin resonance spectra revealed that EDOT was protonated into radical species under p -TsOH. As-obtained PEDOT has a highest average degree of polymerization of 11.3 and the structure details are characterized by 1 H NMR, GPC and FTIR. An acid promoted EDOT protonation polymerization mechanism is proposed and clarified.