HYBRID INORGANIC/ORGANIC POLYMERS WITH NANOSCALE BUILDING BLOCKS: PRECURSORS, PROCESSING, PROPERTIES AND APPLICATIONS

Hybrid polymers (ORMOCER (R) s, Ceramers) are composites with inorganic and organic nanobuilding blocks linked via stable covalent bonds based on organically modified silicon alkoxides and/or functionalized organic oligomers/polymers. A method often used is the formation of the inorganic network by polycondensation reactions (e.g. Si-O-Si bond formation) in a first step, followed by the organic crosslinking (thermal curing at 80-180 degrees C or UV-processing). Another type uses the silylation of organic polymers, with subsequent hydrolysis and polycondensation reactions of the silanized units. The paper focuses on the selection of precursors for various applications and the chemistry involved in processing. Basic properties and the application potential of ORMOCER (R) s as coatings, fibers and composites are presented. Property/composition relationships are shown for mechanical and permeation/barrier properties.