Synthesis and Polymerization of Styrene Monomer Carrying Isothiocyanate Moiety and Its Copolymerization with HEMA Based on Chemo-selectivity to Nucleophiles

Isothiocyanate is a very useful functional group for post-polymerization modification by the reaction with amine or alcohol. An isothiocyanate monomer, 4-vinylbenzyl isothiocyanate, was synthesized from 4-vinylbenzyl chloride without using any harmful reagents such as thiophosgene and CS2. The obtained monomer was successively polymerized by the conventional radical polymerization (AIBN, 1,4-dioxane, 60 degrees C) to afford the corresponding polymer. The obtained polymer was characterized by H-1 NMR, FTIR, thermogravimetric analysis (TGA), and differential scanning calorimetry. In contrast to the isocyanate group, the isothiocyanate group was relatively tolerant to alcohols, and this character enabled us to synthesize a copolymer of 4-vinyl benzylisothiocyanate and (2-hydroxyethyl methacrylate). The copolymer is transformed into networked polymer by 1,8-diazabicyclo[5.4.0]undec-7-ene as a promoter of the reaction between isothiocyanate and alcohol to afford thiocarbamate. The formation of networked polymer was characterized by FTIR and TGA. (c) 2013 Wiley Periodicals, Inc.