Processes of preparing estolide base oils and lubricants that include transesterification
Provided herein are processes of producing estolide base oils, including the process comprising providing at least one fatty acid ester, and contacting the at least one fatty acid ester with at least one fatty acid to form an estolide base oil. Exemplary processes include the use of transesterification to form the at least one fatty acid ester and/or estolide base oil.
1. A process of producing an estolide base oil comprising providing at least one unsaturated fatty acid glyceride;
transesterifying the at least one unsaturated fatty acid glyceride with at least one alcohol to provide at least one fatty acid alkyl ester having at least one site of unsaturation; and
contacting the at least one fatty acid ester with at least one fatty acid in the presence of a catalyst to provide an estolide base oil, wherein the process of producing the estolide base oil includes forming a covalent bond between an oxygen of a carboxylic group of the at least one fatty acid and a carbon of the at least one site of unsaturation of the at least one fatty acid alkyl ester.
2. The process according to claim 1 , wherein the at least one unsaturated fatty acid glyceride is a triglyceride.
3. The process according to claim 2 , wherein the at least one unsaturated fatty acid glyceride is derived from a high-oleic vegetable oil.
4. The process according to claim 1 , wherein the at least one alcohol is a monoalcohol.
5. The process according to claim 4 , wherein the at least one alcohol is a branched or unbranched C 6 -C 12 monoalcohol.
6. The process according to claim 5 , wherein the at least one alcohol is 2-ethylhexanol.
7. The process according to claim 1 , wherein the at least one fatty acid alkyl ester is monounsaturated.
8. The process according to claim 7 , wherein the alkyl residue of the at least one fatty acid alkyl ester is saturated and branched.
9. The process according to claim 1 , wherein the at least one fatty acid is saturated.
10. The process according to claim 9 , wherein the at least one fatty acid is a C 6 -C 14 fatty acid.
11. The process according to claim 1 , wherein the at least one catalyst is a Lewis acid.
12. The process according to claim 11 , wherein the at least one catalyst is a triflate.
13. The process according to claim 1 , wherein the at least one catalyst is a Bronsted acid.
14. The process according to claim 13 , wherein at least one catalyst is selected from one or more of hydrochloric acid, nitric acid, methanesulfonic acid, sulfuric acid, phosphoric acid, perchloric acid, triflic acid, or p-TsOH.
15. The process according to claim 1 , wherein the estolide base oil comprises at least one compound selected from compounds of Formula I:
wherein
x is, independently for each occurrence, an integer selected from 0 to 20;
y is, independently for each occurrence, an integer selected from 0 to 20;
n is an integer greater than or equal to 0;
R 1 is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and
R 2 is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched,
wherein each fatty acid chain residue of said at least one compound is independently optionally substituted.
16. The composition according to claim 15 , wherein
x is, independently for each occurrence, an integer selected from 1 to 10;
y is, independently for each occurrence, an integer selected from 1 to 10;
n is an integer selected from 0 to 8;
R 1 is an optionally substituted C 1 to C 20 alkyl that is saturated or unsaturated, and branched or unbranched; and
R 2 is an optionally substituted C 1 to C 20 alkyl that is saturated or unsaturated, and branched or unbranched,
wherein each fatty acid chain residue is unsubstituted.
17. The process according to claim 16 , wherein
x+y is, independently for each chain, an integer selected from 13 to 15; and
n is an integer selected from 0 to 6.
18. The process according to claim 15 , wherein R 2 is unsubstituted.
19. The process according to claim 18 , wherein R 2 is selected from C 6 to C 12 alkyl.
20. The process according to claim 19 , wherein R 2 is 2-ethylhexyl.
21. The process according to claim 15 , wherein R 1 is unsubstituted.
22. The process according to claim 21 , wherein R 1 is selected from unsubstituted C 7 to C 17 alkyl that is unbranched and saturated or unsaturated.
23. The process according to claim 15 , wherein x is, independently for each occurrence, an integer selected from 7 to 8.
24. The process according to claim 23 , wherein y is, independently for each occurrence, an integer selected from 7 to 8.