Abstract: We prepared and obtained dimercaptomethyl trisulfide containing two structural isomers  5，7-d-imercaptomethyl-1,11-dimercapto-3,6,9-trisulfide and 4,8-dimercaptomethyl-1,11-dimercapto-3,6,9-trisulfide through three steps:  nucleophilic substitution,  chain extension reaction,  and thioetherification and chain extension.  As the core monomer for modifying polyurethane optical materials,  polymeric optical materials could be prepared by synthesizing polythiol composition compounded with polyisocyanate and bisphenol A epoxy resin using this monomer. The experimental results show that the optical material has high transmittance,  high refractive index,  and excellent mechanical properties.

Key words: thioether,  , dithiomethyl,  , trisulfur undecane,  , polyisocyanate,  , bisphenol A epoxy resin