ESR and pulse radiolysis investigation of the radiolysis of sodium vinyl sulfonate

The kinetics of a number of radical reactions involving sodium vinyl sulfonate (SVS) have been studied by pulse radiolysis methods. The initial rate of polymerization of SVS was determined directly by observing the decay of the ESR signal of HOCH₂ĊHSO₃^- in its reaction with SVS monomer. A rate constant of 7 × 10⁴ M^-1 s^-1 was found. The same value was found here for acrylate. Reactions of SVS with the primary radicals produced by radiolysis of water were studied by optical absorption methods. Both OH and O^- add to the double bond with rate constants of (3.5 ± 0.5) × 10⁹ and (3.4 ± 0.5) × 10⁸ M^-1 s^-1, respectively. The hydrated electron adds to the double bond with a rate constant of (2.2 ± 0.2) × 10⁹ M^-1 s^-1. The electron adduct protonates on carbon to yield CH₃ĊHSO₃^-, the same radical as produced by H atom addition. Steady-state ESR experiments confirm the production of ĊHSO₃^- from e1_aq^-. ESR spectra of the radical adducts XCH₂ĊHSO₃^- with X = H, OH, CO^-₂, SO^-₃ and SO^-₄ were obtained in steady-state radiolysis experiments and the magnetic parameters determined.