Silsesquioxanes as Precursors to Ceramic Composites

摘要: Silsesquioxanes having the general structure RSiO sub 1.5, where R = methyl, propyl, or phenyl, melt flow at 70 to 100 C. Above C, free -OH groups condense. At 225 C further crosslinking occurs, and materials form thermosets. Pyrolysis, with accompanying loss of volatiles, takes place nominally 525 higher temperatures, group serves as an internal carbon soruce for carbo-thermal reduction SiC accompanied by evolution CO. By blending silsesquioxanes varying groups, both rheology composition fired ceramic can be controlled. Fibers spun from which are stable in argon 1400 The also were used matrix precursors Nicalon alpha-SiC platelet reinforced composites.