The photo-conversion of pre-polymer mixture NOA65 (Norland, USA) doped with TiO2 nanoparticles is studied by the method of dielectric spectroscopy. The photopolymerized composites show low frequency relaxation and ion conductivity typical for liquids. This is explained by the reaction of TiO2 particles with components of NOA65 mixture that blocks photopolymerization of pre-polymer and increases concentration of ion carriers. In addition, strong photochromism, of NOA65-TiO2 composites is observed which makes, this system quite attractive for non-linear optics and associated applications. It may be caused by formation, of titanium mercaptide and its transfer front IV to III valency state under UV irradiation.