Processes of preparing estolide compounds that include removing sulfonate residues
Provided herein are processes of preparing sulfonated estolide compounds, and the removal of sulfonate residues from those compounds to provide desulfonated estolide base oils. Exemplary sulfonated estolide compounds include those selected from the formula: wherein z is an integer selected from 0 to 15; q is an integer selected from 0 to 15; x is, independently for each occurrence, an integer selected from 0 to 20; y is, independently for each occurrence, an integer selected 0 to 20; n is equal to or greater than 0; R 6 is selected from —OH, optionally substituted alkyl, and optionally substituted aryl; and R 2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, wherein each fatty acid chain residue of said compounds is independently optionally substituted.
1. A process of producing an estolide base oil comprising
providing at least one first estolide compound having at least one mesylate residue, wherein said at least one first estolide compound is selected from compounds of Formula III:
wherein
z is an integer selected from 0 to 12;
q is an integer selected from 0 to 10;
x is, independently for each occurrence, an integer selected from 0 to 10;
y is, independently for each occurrence, an integer selected from 0 to 10;
n is an integer selected from 0 to 8;
R 6 is methyl; and
R 2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched,
wherein each fatty acid chain residue is unsubstituted; and
eliminating the at least one mesylate residue by exposing the at least one first estolide compound to heat and/or basic conditions to provide a demesylated estolide compound that is unsaturated at the site of elimination.
2. The process according to claim 1 , wherein eliminating said at least one mesylate residue includes contacting the at least one first estolide compound with a base.
3. The process according to claim 2 , wherein the base comprises at least one metal hydroxide.
4. The process according to claim 1 , wherein eliminating said at least one mesylate residue includes heating the at least one first estolide compound to a temperature that is greater than 20° C.
5. The process according to claim 4 , wherein eliminating said at least one mesylate residue includes heating the at least one first estolide compound to a temperature of at least 75° C.
6. The process according to claim 5 , wherein eliminating said at least one mesylate residue includes heating the at least one first estolide compound to a temperature of at least 100° C.
7. The process according to claim 6 , wherein eliminating said at least one mesylate residue includes heating the at least one first estolide compound to a temperature of at least 160° C.
8. The process according to claim 5 , wherein eliminating said at least one mesylate residue includes heating the at least one first estolide compound under reduced pressure that is less than 1 atm abs.
9. The process according to claim 8 , wherein the reduced pressure is 250 torr abs or less.
10. The process according to claim 9 , wherein the reduced pressure is 25 torr abs or less.
11. The process according to claim 1 , further comprising hydrogenating the demesylated estolide compound to provide at least one saturated estolide compound.
12. The process according to claim 1 , wherein x is, independently for each occurrence, an integer selected from 7 and 8.
13. The process according to claim 12 , wherein y is, independently for each occurrence, an integer selected from 7 and 8.
14. The process according to claim 1 , wherein R 2 is an unsubstituted alkyl that is saturated or unsaturated, and branched or unbranched.
15. The process according to claim 14 , wherein R 2 is selected from C 6 to C 12 alkyl.
16. The process according to claim 15 , wherein R 2 is saturated and branched.
17. The process according to claim 1 , wherein z is an integer selected from 7 and 8.
18. The process according to claim 17 , wherein q is an integer selected from 7 and 8.
19. The process according to claim 1 , wherein x+y is, independently for each fatty acid chain residue, an integer selected from 13 to 15.
20. The process according to claim 2 , wherein the base is a carboxylate salt.
21. The process according to claim 2 , wherein the base is selected from one or more of a tertiary amine or an aromatic amine.
22. The process according to claim 1 , further comprising esterifying the at least one first estolide compound with at least one alcohol to provide an esterified estolide compound having at least one mesylate residue.