Preparation of Poly(thio-1,4-phenylene)s by Oxygen-Oxidative Polymerization of Diaryl Disulfides

Abstract Oxygen-oxidative polymerization of diphenyl disulfides with vanadyl acetylacetonate (VO(acac)2) was studied by the kinetics based on oxygen uptake. Lineweaver-Burk plots reveal that the oxidation of diphenyl disulfide is a rate-determining step for the VO-catalyzed oxidative polymerization of diphenyl disulfide. Km (Michaelis constant) and Vmax were determined to be 1.6 × 10−2 mol dm−3 and 1.5 × 10−4 mol dm−3 min−1, respectively. The polymerization rate is influenced by the oxidation potential of disulfides. The reoxidation step of the catalyst by oxygen is the rate determining step in case of the polymerization of alkyl-substituted disulfides such as bis(3-methylphenyl)disulfide, bis(2,5-dimethylphenyl)disulfide, and bis(3,5-dimethylphenyl)disulfide because the oxidation step of the disulfides is facilitated due to their lower oxidation potentials.