Anionic copolymerization of elemental sulfur

Abstract

The radical homo- and copolymerization of elemental sulfur has been reviewed. Reasons of inability of elemental sulfur to copolymerize by radical mechanism with vinyl comonomers are given. Anionic copolymerization of elemental sulfur with thiiranes e.g. propylene sulfide and isobutylene sulfide has been described. Application of anionic initiators in hydrocarbon solvents (e.g. benzene, toluene) leads to highmolecular weight copolymers (Mn>10000) with sulfur content in the copolymers reaching 85%. Laser Raman Spectroscopy (LRS) and 1H- and 13C-NMR spectra were used in determination of the structure of copolymers. LRS allowed to show, that elemental sulfur is not present in copolymers. Kinetics of copolymerization was studied and the pertinent kinetic scheme is described, giving access to the ratios of the rate constants. Kinetic analysis has shown that the reactivities of sulfur and propylene sulfide towards thiolate anion are close to each other. © 1981 IUPAC