Monitoring the synthesis of new polymer nanocomposites based on different polyhedral oligomeric silsesquioxanes using Raman spectroscopy

The kinetic behavior of the urethane dimethacrylate (UDMA) copolymerized and reinforced by different concentrations of polyhedral oligomeric silsesquioxane (POSS) with methacrylic groups was studied through Raman spectroscopy. UDMA-POSS networks have been synthesized with three different types of POSS, two moncifunctional POSS (1-propylmethacrylate)-heptaisobutyl substituted (HISO-POSS) and heptacyclopentyl-octasiloxan-1-yloxy) dimethylsilyl] propyl methacrylate (CPENTYL-POSS) and one octafunctional POSS-methacryl substituted (MA-POSS). In order to show the influence of POSS on the final conversion, the hybrid systems were cured using three types of initiators which decompose at different temperatures: azobisisobutyronitrile (AIBN) (65 degrees C), benzoyl peroxide (BP) (80 degrees C) and di-tert-butyl peroxide (DTBP) (120 degrees C). The structure of the hybrid's surface was investigated by X-ray photoelectron spectroscopy (XPS) and the T-g values were calculated from dynamic mechanical analysis (DMA) tests. Copyright (C) 2009 John Wiley & Sons, Ltd.