Catalyst for synthesis of siloxanes
View Patent ↗The present technology provides compositions, methods, and processes to form polysiloxanes. In one aspect, the present technology provides a process for the ring opening polymerization of a cyclosiloxane comprising contacting a cyclosiloxane with a N-trialkylsilyl-bis(perfluoroalkylsulfonyl)imide compound.
1. A process for the ring opening polymerization of a cyclosiloxane comprising contacting a cyclosiloxane and a silanol terminated siloxane with a N-trialkylsilyl-bis(perfluoroalkylsulfonyl)imide compound.
2. The process of claim 1 , wherein the N-trialkylsilyl-bis(perfluoroalkylsulfonyl)imide is of the formula:
where R 1 and R 2 are independently chosen from a perfluoroalkyl radical; and R 3 , R 4 , and R 5 are independently chosen from, a linear or branched alkyl a linear or branched alkyl optionally comprising one or more heteroatoms.
3. The process of claim 2 , wherein the perfluoroalkyl radical is a linear or branched perfluoroalkyl radical having 1-10 carbon atoms.
4. The process of claim 2 , wherein the perfluoroalkyl radical is chosen from —CF 3 , —C 2 F 5 , —C 3 F 7 , —C 4 F 9 , —C 5 F 11 , —C 6 F 13 , —C 7 F 15 , —C 8 F 17 or a combination of two or more thereof.
5. The process of any one of claim 2 - 4 , wherein the alkyl group is chosen from a linear or branched alkyl having 1-10 carbon atoms.
6. The process of claim 2 , wherein R 1 and R 2 are each —CF 3 , and R 3 -R 5 are each CH 3 .
7. The process of claim 1 , wherein the N-trialkylsilyl-bis(perfluoroalkylsulfonyl)imide is present in an amount of from about 0.025 weight percent to about 5 weight percent based on the total weight of the cyclosiloxane.
8. The process of claim 1 , wherein the N-trialkylsilyl-bis(perfluoroalkylsulfonyl)imide is present in an amount of from about 0.1 weight percent to about 0.4 weight percent based on the total weight of the cyclosiloxane.
9. The process of claim 1 , wherein the cyclosiloxane is of the formula (R 6 R 7 SiO) n , wherein R 6 and R 7 are independently chosen from hydrogen or an optionally substituted alkyl, alkenyl, aryl, alkaryl or aralkyl group having up to 8 carbon atoms, and n denotes an integer with a value of from 3 to 12.
10. The process of claim 1 , wherein the cyclosiloxane is chosen from octamethyl cyclotetrasiloxane (D4), hexamethylcyclotrisiloxane (D3), octaphenylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethyl-1,1-diphenylcyclotetrasiloxane, decamethyl pentacyclosiloxane, cyclopenta (methylvinyl) siloxane, cyclotetra(phenylmethyl) siloxane, cyclopenta methylhydrosiloxane, or a combination of two or more thereof.
11. The process of claim 1 comprising two or more cyclosiloxanes, where at least two cyclosiloxanes have a different ring size from each other.
12. The process of claim 1 , wherein the reaction comprises an endblocker material.
13. The process of claim 12 , wherein the endblocker material is chosen from hexamethyl di siloxane; octamethyltrisiloxane; decamethyltetrasiloxane; dodecamethylpentasiloxane; tetradecamethylhexasiloxane; hexadecamethylheptasiloxane, hydride substituted siloxane or a combination of two or more thereof.
14. The process of claim 1 further comprising deactivating the catalyst.
15. The process of claim 14 , wherein deactivating the catalyst comprises: treating the product with a material to neutralize the catalyst such as a base or a basic resin, or a combination of two or more thereof.
16. The process of claim 14 further comprising filtering the reaction mixture.
17. The process of claim 1 , wherein the silanol terminated siloxane is silanol terminated poly(dimethylsiloxane).