Radiation‐induced polymerization of isoprene in aqueous solution of silver nitrate

Abstract

AbstractThe rate of radiation‐induced polymerization of isoprene in aqueous solution of silver nitrate is 20–50 times as fast as the rate of radiation‐induced polymerization of pure isoprene. The formation of a 1:2 complex of isoprene and silver nitrate was confirmed spectrometrically, and this complex seems to polymerize by attack of an active species. The equilibrium constant Kf and the extinction coefficient E of the complex were estimated to be 0.18 and 1.4, respectively. The polymerization mechanism was concluded to be a radical one, based on the effects of inhibitors. The polyisoprene obtained had a crosslinked structure, was insoluble, and did not give a distinct melting point. The 1,2 structure was the predominant polyisoprene configuration. This was interpreted on the basis of the frontier electron density of isoprene.