Functionalized Polyhedral Oligosilsesquioxane (POSS) Macromers: New Graftable POSS-Hydride, POSS-Alpha-Olefin, POSS-Epoxy, and POSS-Chlorosilane Macromers and POSS-Siloxane Triblocks

A series of polyhedral oligomeric silsesquioxanes (POSS) monomers bearing silane or alpha-olefin substituents have been prepared and their chemistry explored. Both the POSS silanes and alpha-olefin monomers readily participate in hydrosilation chemistry and have been used as starting materials for the preparation of POSS sol-gel type reagents. Similarly, POSS silanes and alpha-olefins are reactive towards silane and olefin functionalized polymers which makes them useful as grafting reagents. The utility of these reagents as graftable monomers was demonstrated by synthesis of a series of POSS-siloxane-POSS triblock polymers. Thermal and X-ray diffraction (XRD) characterization of the triblock polymers was performed in order to examine how the length of the siloxane segment effects the properties of the polymer. The reactivity of the POSS-alpha-olefin monomers with respect to ziegler-Natta and free radical polymerization was also examined. The reaction of POSS-alpha-olefins with MCPBA to give POSS-epoxides was demonstrated and the thermal stability of the POSS-epoxides determined.