Thermogravimetric study of the kinetics of formation of poly(para-phenylene vinylene) by thermal conversion of a sulfonium precursor

Poly(p-phenylene vinylene) (PPV) conjugated polymer films were prepared by thermolytic conversion of poly[p-phenylene (tetrahydrothiophenium)ethylene chloride] precursor films, at different temperatures. The reaction kinetics was investigated by isothermal thermogravimetry. Each conversion temperature was found to be associated with an asymptotic value of mass loss. A mathematical analysis relating molar conversion to asymptotic mass loss was derived. The activation energy for dehydrochlorination of the poly(p-phenylene chloroethylene) intermediate was found to be 59 ± 7 kJ mol−1, significantly lower than that for the dehydrochlorination of poly(vinyl chloride) (PVC). The reaction order, on the other hand, was nearly first-order, similar to that for PVC. Film processing conditions that gave conjugated polymer films free of carbonyl defects were identified.