Functionalized polyhedral oligosilsesquioxane (POSS) macromers: new graftable POSS hydride, POSS α-olefin, POSS epoxy, and POSS chlorosilane macromers and POSS–siloxane triblocks

Abstract

A series of polyhedral oligomeric silsesquioxanes (POSS) monomers bearing silane or α-olefin substituents have been prepared and their chemistry explored. Both the POSS silanes and α-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 α-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. Thermal­and X-ray diffraction (XRD) characterization of the triblock polymers was performed in order to examine how the length of the siloxane segment affects the properties of the polymer. The POSS α-olefin monomers were found to­be unreactive with respect to Ziegler–Natta polymerization. The reaction of POSS α-olefins with m -chloroperbenzoic acid (MCPBA) to give POSS epoxides was demonstrated and the thermal stability of the POSS epoxides determined. Copyright © 1999 John Wiley & Sons, Ltd.