High flexural strength ceramic fiber reinforced silicon carboxide composite

Claim 1

A method of preparing fiber reinforced glass composites comprising: (a) reacting (1) a cyclosiloxane monomer having the formula ##STR3## where n is an integer from 3 to 30, R is hydrogen, and R' is an alkene of from 2 to 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon or (2) two or more different cyclosiloxane monomers having the formula of (1) where for at least one monomer R is hydrogen and R' is an alkyl group having from 1 to 20 carbon atoms and for the other monomers R is an alkene from 2 to 20 carbon atoms in which one vinyl carbon is directly bonded to silicon and R' is an alkyl group of from 1 to 20 carbon atoms, said reaction taking place in the presence of an effective amount of hydrosilylation catalyst; (b) applying the reaction product of (a) to at least one refractory fiber having a carbon coating about 0.01 μm to 5 μm thick and selected from the group consisting of boron, silicon carbide, graphite, silica, quartz, S-glass, E-glass, alumina, aluminosilicate, boron nitride, silicon nitride, boron carbide, titanium boride, titanium carbide, zirconium oxide and zirconiatoughened alumina to form a prepreg; (c) laying-up plies of the prepreg of (b) to form a green structure; (d) curing the green structure of (c) at a temperature not greater than 250° C.; (e) pyrolyzing the cured structure of (d) at a temperature of about 800° C. to about 1400° C. in non-oxidizing atmosphere; (f) recovering the pyrolyzed product of (e) as the fiber reinforced glass composite; (g) impregnating the pyrolyzed product of (f) with the reaction product of (a); (h) pyrolyzing the impregnated product of (g) at 800° C.-1400° C.; (i) repeating steps (g) and (h) to achieve the desired density.

Claim 2

A method of preparing fiber reinforced glass composites comprising: (a) reacting (1) a cyclosiloxane monomer having the formula ##STR3## where n is an integer from 3 to 30, R is hydrogen, and R' is an alkene of from 2 to 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon or (2) two or more different cyclosiloxane monomers having the formula of (1) where for at least one monomer R is hydrogen and R' is an alkyl group having from 1 to 20 carbon atoms and for the other monomers R is an alkene from 2 to 20 carbon atoms in which one vinyl carbon is directly bonded to silicon and R' is an alkyl group of from 1 to 20 carbon atoms, said reaction taking place in the presence of an effective amount of hydrosilylation catalyst; (b) applying the reaction product of (a) to at least one refractory fiber having a carbon coating about 0.01 μm to 5 μm thick and selected from the group consisting of boron, silicon carbide, graphite, silica, quartz, S-glass, E-glass, alumina, aluminosilicate, boron nitride, silicon nitride, boron carbide, titanium boride, titanium carbide, zirconium oxide and zirconiatoughened alumina to form a prepreg; (c) laying-up plies of the prepreg of (b) to form a green structure; (d) curing the green structure of (c) at a temperature not greater than 250° C.; (e) pyrolyzing the cured structure of (d) at a temperature of about 800° C. to about 1400° C. in non-oxidizing atmosphere; (f) recovering the pyrolyzed product of (e) as the fiber reinforced glass composite; (g) impregnating the pyrolyzed product of (f) with the reaction product of (a); (h) pyrolyzing the impregnated product of (g) at 800° C.-1400° C.; (i) repeating steps (g) and (h) to achieve the desired density.

Claim 10

A method of preparing fiber reinforced glass composites comprising: (a) placing into a mold at least one refractory fiber, optionally having a carbon coating about 0.01 μm to 5 μm thick and selected from the group consisting of boron, silicon carbide, graphite, silica, quartz, S-glass, E-glass, alumina, aluminosilicate, boron nitride, silicon nitride, boron carbide, titanium boride, titanium carbide, zirconium oxide, and zirconia-toughened alumina; (b) filling the mold of (a) with (1) a cyclosiloxane monomer having the formula ##STR4## where n is an integer from 3 to 30, R is hydrogen, and R' is an alkene of from 2 to 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon or (2) two or more different cyclosiloxane monomers having the formula of (1) where for at least one monomer R is hydrogen and R' is an alkyl group having from 1 to 20 carbon atoms and for the other monomers R is an alkene from 2 to 20 carbon atoms in which one vinyl carbon is directly bonded to silicon and R' is an alkyl group of from 1 to 20 carbon atoms, and an effective amount of hydrosilylation catalyst; (c) reacting the monomers of (b) at a temperature of about 30° C. to 150° C. to form a green composite; (d) pyrolyzing the green composite of (c) at a temperature of about 800° C. to about 1400° C. in non-oxidizing atmosphere; (e) recovering the pyrolyzed product of (d) as the fiber reinforced glass composite; (f) impregnating the pyrolyzed product of (e) with the reaction product of the monomers of (b); (g) pyrolyzing the impregnated product of (f) at 800° C.-1400° C.; (h) repeating steps (f) and (g) to achieve the desired density.

Claim 11

A method of preparing fiber reinforced glass composites comprising: (a) placing into a mold at least one refractory fiber, optionally having a carbon coating about 0.01 μm to 5 μm thick and selected from the group consisting of boron, silicon carbide, graphite, silica, quartz, S-glass, E-glass, alumina, aluminosilicate, boron nitride, silicon nitride, boron carbide, titanium boride, titanium carbide, zirconium oxide, and zirconia-toughened alumina; (b) filling the mold of (a) with (1) a cyclosiloxane monomer having the formula ##STR4## where n is an integer from 3 to 30, R is hydrogen, and R' is an alkene of from 2 to 20 carbon atoms in which one vinyl carbon atom is directly bonded to silicon or (2) two or more different cyclosiloxane monomers having the formula of (1) where for at least one monomer R is hydrogen and R' is an alkyl group having from 1 to 20 carbon atoms and for the other monomers R is an alkene from 2 to 20 carbon atoms in which one vinyl carbon is directly bonded to silicon and R' is an alkyl group of from 1 to 20 carbon atoms, and an effective amount of hydrosilylation catalyst; (c) reacting the monomers of (b) at a temperature of about 30° C. to 150° C. to form a green composite; (d) pyrolyzing the green composite of (c) at a temperature of about 800° C. to about 1400° C. in non-oxidizing atmosphere; (e) recovering the pyrolyzed product of (d) as the fiber reinforced glass composite; (f) impregnating the pyrolyzed product of (e) with the reaction product of the monomers of (b); (g) pyrolyzing the impregnated product of (f) at 800° C.-1400° C.; (h) repeating steps (f) and (g) to achieve the desired density.