UV-cured organic-inorganic hybrid nanocomposite initiated by trimethoxysilane-modified fragmental photoinitiator

An effective approach is proposed to prepare the UV-cured organic inorganic hybrid nanocomposite (Nano-TMS) through the photopolymerization of acrylic resin initiated by trimethoxysilane-modified Irgacure 2959 (TMS-2959). The TMS-2959 as a hybrid photoinitiator was obtained by the esterification of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) with thioglycolic acid, following by the addition reaction with 3-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560). The chemical structure was characterized by FT-IR and (1)H NMR spectroscopy. The oligomeric tetraethylorthosilicate (Oligo-TEOS) was prepared by hydrolysis. The TMS-2959 exhibits the similar UV absorption with Irgacure 2959. The photoinitiating activity of TMS-2959 was investigated through photo-DSC analysis in comparison with Irgacure 2959. From the SEM observation, the SiO(2) nanoparticles dispersed uniformly in the Nano-TMS film, whereas the aggregation of nanoparticles occurred in the UV-cured hybrid nanocomposite (Nano-kg) initiated by Irgacure 2959. Compared with the UV-cured pure polymer and Nano-kg films, the cured Nano-TMS films showed remarkable enhanced thermal stability and mechanical properties. (C) 2011 Elsevier Ltd. All rights reserved.