Journal of Applied Polymer Science, Vol.105, No.3, 1426-1436, 2007
Polymerization of methacryl and triethoxysilane functionalized stearate ester: Titanium dioxide a composite films and their photocatalytic degradations
Stearoyl chloride was reacted with 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM). Then the resulting product (SAHM) was reacted with 3-amino propyl ethoxysilane (APTES) by Michael addition on the acrylate. The product (SAHMA) is a specialized coupling agent containing an oleophilic 18 carbon alkyl chain, a radically polymerizable methacrylate and an alkoxysilane group capable of coupling to inorganic surfaces, analyzed by FT-IR, NMR, and UV techniques. Photopolymerization and free radical homo and copolymerization of SAHMA with styrene were examined. SAHMA was coupled to powdered titanium dioxide (P25-Degussa) and polymerized. TiO2 filled materials were analyzed by SEM, UV and TGA techniques. Glass transiton temperatures (T-g) of the polymers were determined by differential scanning calorimeter (DSC). Interfacial compatibility between SAHMA and TiO2 was demonstrated by FT-IR spectroscopy. The photocatalytic degradation of the TiO2-SAHMA polymer films was also investigated under medium pressure mercury lamp illumination in air. SAHMA based film containing 2 wt % TiO2 showed the highest degradation and the highest loss in weight. The weight of the polymer was reduced by 25% of its initial value after irradiation for 40 h. To examine the surface morphology of the irradiated polymer films, SEM analysis was carried out and cavities were detected around TiO2 particles. The photocatalytic and thermomechanical properties of SAHMA and styrene (STY) based copolymers were also investigated. (c) 2007 Wiley Periodicals, Inc.