Styrene and Methyl Methacrylates Resins Containing POSS

Styrene and Methyl Methacrylates Resins Containing POSS 

The unfunctionalized POSS molecules, octaisobutyl-POSS, and dode-caphenyl-POSS (Fig. 1), Tg and T12, were blended into DCPD. No chemical bonds can form between these POSS units and the DCPD crosslinked network during curing. As the polymerization proceeds, phase-separated POSS particles are formed with size distributions in the 5-50 or 60 pm region. They appear to lower Tg, and stiffness is lost both above and below the glass-transition temperature. Perhaps this occtus because the volume they occupy does not provide any continuous bonding, so tiiey act like inert filler particles without special adhesion to the resin. 

The Tg values dropped from 132.2°C to 123.7°C in the 1 wt % BDMA crosslink methacrylate resins as the weight percent of POSS-39 went from 0 wt % to 20 wt %. The densities of these resins also dropped as the POSS-39 content went up. For example, P(MMA-co-5% BDMA) has p = 1.188g/cc. This drops to 1.176g/cc 

Li and Pittman copolymerized POSS-32 with styrene using a MEK peroxide/ cobalt napthanate radical initiator system. Swellable crosslinked gels were obtained at POSS-32 of 0.44 mol % and 0.88 mol %. No POSS-32 could be extracted from these systems. Therefore, all the POSS-32 originally charged to the reaction 

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C. Styrene and Methyl Methacrylates Resins Containing POSS 117... 

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