Synthesis, structure and characterization of the new sulfur monomer sulfinylbis[benzene-4,1-diyl(oxy-2-hydroxypropane-3,1-diylmethacrylate)] (SO.DM) and its photopolymerization with N-vinyl-2-pyrrolidone (NVP) are presented. SO.DM was obtained in the three-step reaction. In the first step, 4,4'-sulfinylbisphenol from 4-[(4-hydroxyphenyl)thio]phenol was obtained. In the second step the epoxy compound was synthesized. It was obtained in the reaction of 4,4'-sulfinylbisphenol with 2-(chloromethyl)oxirane in the two phases liquid/liquid system including organic and aqueous phases. In the third step, ring opening of the obtained diglycidyl ether was carried out with the use of methacrylic acid in the presence of triethylbenzylammonium chloride (TEBAC) as a catalyst. Structures of new compounds were confirmed by spectroscopic methods (FT-IR, 1 H and 13
C-NMR and DIP-MS).Photopolymerization of compositions containing different ratios of the monomers (SO.DM and NVP) and an initiator (Irgacure 651) was carried out. The following properties (before and after curing) were determined: density, polymerization shrinkage, glass transition temperature, Young's modulus, hardness, tensile strength. Moreover, dynamic-mechanical and thermal properties were studied.