Hybrid Styryl-Based Polyhedral Oligomeric Silsesquioxane (Poss) Polymers

Abstract

The authors have taken a unique approach to the synthesis and study of hybrid organic/inorganic materials. The method involves synthesizing nano-size inorganic P{sub 1}R{sub 7}Si{sub 8}O{sub 12} clusters which contain seven inert R groups for solubility and only one functional P group for polymerization. This strategy permits the synthesis of melt processable, linear hybrid polymers containing pendent inorganic clusters and allows one to study the effect these clusters have on chain motions and polymer properties. The synthesis of styrene-based polyhedral oligomeric silsesquioxane (POSS) macromers, their free radical homopolymerization and copolymerizations with varying amounts of 4-methylstyrene, and analysis of the effect of the pendent POSS group is presented. All of these polymers decompose under nitrogen between 365 and 400 C, and the glass transitions for these materials vary from around 110 C up to the decomposition point. Both T{sub dec} and T{sub g} increase with increasing POSS content. The shorter the spacer unit between the POSS group and the polymer chain the higher the T{sub g}. Interestingly, a slight change in the inert R groups on the POSS cluster has a large effect on the glass transition indicating that POSS-POSS interactions have an effect on chain mobility.