Reaction analysis of 3,4-ethylenedioxythiophene with potassium persulfate in aqueous solution by using a calorimeter

摘要

A calorimeter was used to directly monitor the rate of emulsion polymerization of 3,4-ethylenedixoythioxythiophene (EDOT)inaqueous solution for different concentations of the initiator, potassium persulfate (KPS). The reaction involved polymerization and doping in one step, and yielded a poly(3,4-ethylenedioxythiophene)(PEDOT)with electrical conductivity. The electrical conductivity and yield of PEDOT increased as the molar ratio of KPS to EDOT increased until the molar ratio of unity. The they decreased. The reaction rate was found to be governed bythe concentration of the reactants:R_p propor. to [KPS]~(0.64)*[DEOT]~(0.16). The exponent of EDOT concentration had so low value that the reaction was of approximately zero order,which could be explained by the presence of a so-called degradative addition. In additon, the effect of sulfuric acid on the polymerization rate of EDOT was also investigated. The reaction rate reached the maximum at pH 2.7.