Copolymerization of elemental sulfur to synthesize high sulfur content polymeric materials

Abstract

Copolymerization of elemental sulfur with functional comonomers afford sulfur copolymers having a high molecular weight and high sulfur content. Nucleophilic activators initiate sulfur polymerizations at relative lower temperatures and in solutions, which enable the use of a wider range of comonomers, such as vinylics, styrenics, and non-homopolymerizing comonomers. Nucleophilic activators promote ring-opening reactions to generate linear polysulfide intermediates that copolymerize with comonomers. Dynamic sulfur-sulfur bonds enable re-processing or melt processing of the sulfur polymer. Chalcogenide-based copolymers have a refractive index of about 1.7-2.6 at a wavelength in a range of about 5000 nm-8μιτι. The sulfur copolymer can be a thermoplastic or a thermoset for use in elastomers, resins, lubricants, coatings, antioxidants, cathode materials for electrochemical cells, dental adhesives/restorations, and polymeric articles such as polymeric films and free-standing substrates. Optical substrates are constructed from the chalcogenide copolymer and are substantially transparent in the visible and infrared spectrum.