US4767728A
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Boron-containing organosilane polymers and ceramic materials thereof
Assignee: United States, ADMINISTRATOR OF NASA, Secretary of
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Filing: 1986-07-30
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Granted: 1988-08-30
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Expires: 2006-07-30
Abstract
Abstract The present invention relates to a polyorganoborosilane ceramic precursor polymer comprising a plurality of repeating units of the formula: <IMAGE> with the segments being linked together by second units of the formula: -(R2)-Si-R3)-q, where R1 is lower alkyl, cycloalkyl, phenyl, or <IMAGE> and R2 and R3 are each independently selected from hydrogen, lower alkyl, vinyl, cycloalkyl, or aryl, n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100. These materials are prepared by combining an organoborohalide of the formula R4-B-(X1)2 where R4 is selected from halogen, lower alkyl, cycloalkyl, or aryl, and an organohalosilane of the formula : R2 (R3) Si(X2)2 where R2 and R3 are each independently selected from lower alkyl, cycloalkyl, or aryl, and X1 and X2 are each independently selected from halogen, in an anhydrous aprotic solvent having a boiling point at ambient pressure of not greater than 160 DEG C. with in excess of four equivalents of an alkali metal, heating the reaction mixture and recovering the polyorganoborosilane. These silicon boron polymers are useful to generate high-temperature ceramic materials, such as SiC, SiB4, and B4C, upon thermal degradation above 600 DEG C.
Inventors
- 👤 Salvatore R. Riccitiello
- 👤 Ming-Ta S. Hsu
- 👤 Timothy S. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:51
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/622; C04B35/62227
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
107 words
A process for the preparation of a ceramic material, which process comprises: pyrolyzing at a temperature above 600° C. in an inert atmosphere a polyorganoborosilane ceramic precusor polymer comprising a plurality of repeating units of the formula: ##STR10## the polymer unit being linked together by second units of the formula: ##STR11## wherein R 1 is selected from lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR12## wherein: R 2 and R 3 are each independently selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100.
Claim 2
Dependent Claim
107 words
A process for the preparation of a ceramic material, which process comprises: pyrolyzing at a temperature above 600° C. in an inert atmosphere a polyorganoborosilane ceramic precusor polymer comprising a plurality of repeating units of the formula: ##STR10## the polymer unit being linked together by second units of the formula: ##STR11## wherein R 1 is selected from lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR12## wherein: R 2 and R 3 are each independently selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100.
Claim 3
Dependent Claim
10 words
The process of claim 1 wherein R 1 is methyl.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein R 2 and R 3 are each methyl.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein R 1 is phenyl and R 2 and R 3 are each methyl.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein R 1 is selected from phenyl or ##STR13##
Claim 7
Dependent Claim
119 words
A process for the preparation of a ceramic material which process consists essentially of: (a) pyrolyzing at a temperature above 600° C. in an inert atmosphere a polyorganoborosilane ceramic precusor polymer itself consisting essentially of a plurality of repeating units of the formula: ##STR14## the polymer unit being linked together by second units of the formula: ##STR15## wherein R 1 is lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR16## wherein R 2 and R 3 are each independently selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100; and (b) recovering the ceramic material obtained thereby.
Claim 8
Dependent Claim
119 words
A process for the preparation of a ceramic material which process consists essentially of: (a) pyrolyzing at a temperature above 600° C. in an inert atmosphere a polyorganoborosilane ceramic precusor polymer itself consisting essentially of a plurality of repeating units of the formula: ##STR14## the polymer unit being linked together by second units of the formula: ##STR15## wherein R 1 is lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR16## wherein R 2 and R 3 are each independently selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100; and (b) recovering the ceramic material obtained thereby.
Claim 9
Dependent Claim
10 words
The process of claim 6 wherein R 1 is methyl.
Claim 10
Dependent Claim
14 words
The process of claim 7 wherein R 2 and R 3 are each methyl.
Claim 11
Dependent Claim
19 words
The process of claim 6 wherein R 1 is phenyl and R 2 and R 3 are each methyl.
Claim 12
Dependent Claim
10 words
The process of claim 6 wherein R 1 is ##STR17##
Claim 13
Dependent Claim
232 words
A process for the preparation of a ceramic material, which process consists essentially of: (a) combining an organoborohalide of the formula R 4 -B-(X 1 ) 2 and an organohalosilane of the formula R 2 R 3 Si(X 2 ) 2 wherein R 4 is selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; R 2 and R 3 are each independently selected from lower alkyl, vinyl, cycloalkyl, aryl, or substituted aryl; and X 1 and X 2 are each independently selected from chloro or bromo, in an aprotic solvent having a boiling point at ambient pressure of not greater than 160° C., with at least four equivalents of an alkali metal; (b) heating the reaction mixture for a time and at a temperature up to 160° C. effective to produce a polyorganoborosilane; (c) pyrolyzing at a temperature above 600° C. in an inert atmosphere the polyorganoborosilane polymer of step (b) which consists essentially of a plurality of repeating units of the formula: ##STR18## the polymer unit being linked together by second units of the formula: ##STR19## wherein R 1 is lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR20## wherein R 2 and R 3 are each independently defined hereinabove, n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100; and (d) recovering the ceramic material obtained thereby.
Claim 14
Dependent Claim
232 words
A process for the preparation of a ceramic material, which process consists essentially of: (a) combining an organoborohalide of the formula R 4 -B-(X 1 ) 2 and an organohalosilane of the formula R 2 R 3 Si(X 2 ) 2 wherein R 4 is selected from halogen, lower alkyl, vinyl, cycloalkyl, or phenyl; R 2 and R 3 are each independently selected from lower alkyl, vinyl, cycloalkyl, aryl, or substituted aryl; and X 1 and X 2 are each independently selected from chloro or bromo, in an aprotic solvent having a boiling point at ambient pressure of not greater than 160° C., with at least four equivalents of an alkali metal; (b) heating the reaction mixture for a time and at a temperature up to 160° C. effective to produce a polyorganoborosilane; (c) pyrolyzing at a temperature above 600° C. in an inert atmosphere the polyorganoborosilane polymer of step (b) which consists essentially of a plurality of repeating units of the formula: ##STR18## the polymer unit being linked together by second units of the formula: ##STR19## wherein R 1 is lower alkyl, vinyl, cycloalkyl, phenyl, or ##STR20## wherein R 2 and R 3 are each independently defined hereinabove, n is an integer between 1 and 100; p is an integer between 1 and 100; and q is an integer between 1 and 100; and (d) recovering the ceramic material obtained thereby.
Claim 15
Dependent Claim
10 words
The process of claim 11 wherein R 1 is methyl.
Claim 16
Dependent Claim
14 words
The process of claim 12 wherein R 2 and R 3 are each methyl.
Claim 17
Dependent Claim
19 words
The process of claim 13 wherein R 1 is phenyl and R 2 and R 3 are each methyl.
Claim 18
Dependent Claim
10 words
The process of claim 11 wherein R 1 is ##STR21##
Claim 19
Dependent Claim
40 words
The ceramic product of the process of claim 1, wherein the product comprises SiC, SiB 4 , SiB 6 , and B 4 C, and the sum of the SiB 4 and SiB 6 present is about 17% or greater.
Claim 20
Dependent Claim
39 words
The ceramic product of the process of claim 2, wherein the product comprises SiC, SiB 4 , SiB 6 and B 4 C, and the sum of the SiB 4 and SiB 6 present is about 17% or greater.
Claim 21
Dependent Claim
39 words
The ceramic product of the process of claim 3, wherein the product comprises SiC, SiB 4 , SiB 6 and B 4 C, and the sum of the SiB 4 and SiB 6 present is about 17% or greater.
Claim 22
Dependent Claim
39 words
The ceramic product of the process of claim 4, wherein the product comprises SiC, SiB 4 , SiB 6 and B 4 C, and the sum of the SiB 4 and SiB 6 present is about 17% or greater.
Claim 23
Dependent Claim
39 words
The ceramic product of the process of claim 5, wherein the product comprises SiC, SiB 4 , SiB 6 and B 4 C, and the sum of the SiB 4 and SiB 6 present is about 17% or greater.
Claim 24
Dependent Claim
36 words
The ceramic material of claim 1, which consists essentially of SiC, SiB 4 , SiB 6 and B 4 C, wherein the sum of the SiB 4 and SiB 6 present is about 17% or greater.
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