INORGANIC-ORGANIC COPOLYMERS AS SOLID-STATE IONIC CONDUCTORS WITH GRAFTED ANIONS

Inorganic-organic copolymers (ORMOCER(R)s) are hybrid polymeric materials consisting of interconnected inorganic oxidic (Si, Al, Zr, etc.) components and organic (polyethylene, poly(meth-)acrylates, polyethylene oxides, etc.) components. Synthesis is carried out via sol-gel processing in combination with organic crosslinking reactions of reactive functionalized organosilanes. Depending on chemical composition and processing parameters, special properties are available to meet the material requirements of applied technology. To overcome the general problems resulting from anion movement in using salts and acids, alkyl-sulfone functionalized alkoxysilanes were cocondensed with reactive polymerizable alkoxysilanes such as 3-methacryloxypropyl- (for uv-initiated polymerization of the organics) and 3-glycidoxypropyl-trimethoxysilane (for thermally initiated polymerization). ORMOCER(R) resins containing grafted lithium sulfone groups produce, after final curing of the organics, amorphous membranes and coatings with high conductivities up to 10(-5)Omega(-)cm(-1) at RT without plastizisers. Considering proton conductors, optically transparent water stable membranes with proton conductivities up to 10(-2)Omega(-1)cm(-1) at RT are available depending on the content of -SO3H groups and coordinated water. Thermal stability of the amorphous network has been measured up to 180 degrees C.