Structure characterization of organic-inorganic nanocomposites formed by the sol-gel polycondensation

摘要

The organic-inorganic (O-I) hybrid networks were prepared from well-defined O-I precursors (a) alkoxysilane-endcapped oligomers (ASO) and (b) epoxy-functional silsesquioxane (SSQO) clusters (EC). ASO precursors were crosslinked by sol-gel polycondensation and EC by the reaction of the epoxy groups with oligomeric diamine Jeffamine D2000. Formation, structure and mechanical properties of the networks were followed by SEC, NMR, SAXS and DMA. The O-I block copolymer network is composed of SSQO domains forming network junctions linked by an oligomer chain. Structure of the SSQO crosslink "points" ranges from compact polyhedral cages to large loose SSQO clusters in dependence on the precursor type and catalysis of the sol-gel process. Interphase interaction and mechanical properties of the O-I networks are discussed.