Polymerization of Methyl Methacrylate by Charge-Transfer Mechanism with Sodium Azide and Iron(III) Complex

Abstract

Polymerization of methyl methacrylate (MMA) by the charge-transfer complex formed by the interaction of sodium azide (NaN3), MMA, and carbon tetrachloride (CCl4) has been studied in dimethylsulfoxide (DMSO) medium at 60°C. The polymerization can be vastly accelerated by Lewis acids like Fe3+. This paper reports the polymerization of MMA initiated by NaN3 and CCl4 and accelerated with hexakis(dimethylsulfoxide)iron (III) perchlorate [Fe(DMSO)6] (ClO4)3 at 60°C. The rate of polymerization, Rp, was found to vary as [NaN3]0.53 and [MMA]1.43. The presence of Fe(N3)3 in the polymerization system produced well defined induction periods. The rate constant at 60°C for the interaction of poly(MMA) radical towards Fe(N3)3 was calculated to be 1.09×105 l mol−1s−1.