Autocatalytic oxidative polymerization of indene by cobalt porphyrin complex and kinetic investigation of the polymerization of styrene

Abstract

This is the first report on the oxidative polymerization of indene using cobalt(II) tetraphenyl porphyrin pyridine [Co(II)TPP(Py)] complex, which led to the formation of poly(indene peroxide), PINDP, having narrow polydispersity. The polymerization was carried out at room temperature and low oxygen pressure. The dual behavior of Co(II)TPP(Py) as a dioxygen carrier as well as an initiator was investigated. The mechanism of polymerization is described and supported from the kinetic analysis, UV-visible, ESR, and 1H NMR studies. The rate of formation of PINDP is higher for Co(II)TPP(Py) catalyzed polymerization compared to the usual free radical, AIBN, initiated polymerization. The stability of PINDP was estimated from its rate of degradation and compared with other related vinyl polyperoxides. The PINDP was further used as a peroxide macroinitiator for the polymerization of styrene. The polymerization obeys classical kinetics. The K² values of the peroxide macroinitiator was determined, which reveals that it can also be used at higher temperature for the polymerization. An "active" polystyrene was also synthesized, containing peroxy segments at the chain ends.