Synthesis of regioblock polystyrene by a template monomer technique

Abstract

In this study, we synthesized for the first time a well-defined model polymer of regioblock polystyrene (PS) comprising pure head-to-tail and head-to-head blocks through living anionic block copolymerisation of styrene and 2,3-diphenyl-1,3-butadiene (DPB), followed by hydrogenation using Na/isopropanol reagent. In the polymerisation of DPB, it was critical to use a mixed solvent of cyclohexane with a small amount of THF to attain high solubility. Since DPB polymerized exclusively in 1,4-addition manner, the resulting block copolymers were readily transformed into the regioblock PS by hydrogenation of the residual double bonds in the main chain. The structure of the regioblock PS thus synthesized were confirmed by carefully characterizing with GPC, 1H NMR, 13C NMR, UV–Vis and Raman spectra.