Obtaining of Hybrid Nanocomposites by Simultaneous Photopolymerization of Some Urethane Monomers and Photoinduced Formation of Gold Nanoparticles

Urethane-urea dimethacrylates were synthesized and used in the preparation of nanocomposites containing gold nanoparticles (Au NPs) in situ photogenerated during the UV-curing process in the absence of reducing agent. A study of the photopolymerization kinetics showed that the photoreactivity of the monomers alone or in combination with a dual urethane benzophenone (BP) macromer is dependent on the nature of photoinitiator (Irgacure819, BP/amine) and the formulation composition. It was found that the addition of 1 wt % AuBr3 in monomers slightly improved the polymerization rate and the degree of conversion. The formation of Au NPs into the network was confirmed through UV-vis, XRD, EDX, SAXS, and TEM analyses, the last indicating the existence of NPs with size around 8.5 nm and spherical/triangle shapes. On addition of 10 wt % 2[N-methacryloyloxyethyl-(N'-2-thioethyl)] (urea) in formulation, the Au NPs (200 nm) became predominantly cubic/hexagonal in shape. The composite films emit fluorescence at 575 nm, and this property could be exploited in the field of fluorescent bio/sensors. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 728-738