High- and low-viscosity estolide base oils and lubricants
Provided herein are compounds of the formula: in which n is an integer equal to or greater than 1; R 2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R 1 , R 3 , and R 4 , independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, wherein compositions comprising the compounds are characterized by particular combinations of values for estolide number, kinematic viscosity, and pour point. Also provided are compositions containing the compounds and methods of making both the compounds and compositions thereof.
1. A composition consisting essentially of at least one estolide compound, said composition having:
an EN that is an integer or fraction of an integer selected from 1.0 to 1.6, wherein the EN is the average number of estolide linkages in compounds according to Formula I; and
a kinematic viscosity of about 4 cSt to about 10 cSt when measured at 100° C.,
wherein said at least one estolide compound is selected from compounds of Formula I:
wherein
x is, independently for each occurrence, an integer selected from 7 and 8;
y is, independently for each occurrence, an integer selected from 0, 1, and 2;
n is an integer selected from 0 to 4;
R 1 is an unsubstituted C 7 to C 17 alkyl that is saturated and branched or unbranched; and
R 2 is an unsubstituted C 1 to C 18 alkyl that is saturated or unsaturated, and branched or unbranched,
wherein each fatty acid chain residue of said at least one estolide compound is unsubstituted.
2. The composition according to claim 1 , wherein x+y is 7 for each fatty acid chain residue.
3. The composition according to claim 1 , wherein x+y is 8 for each fatty acid chain residue.
4. The composition according to claim 1 , wherein R 2 is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecanyl, dodecanyl, tridecanyl, tetradecanyl, pentadecanyl, hexadecanyl, heptadecanyl, and octadecanyl, which are saturated and branched or unbranched.
5. The composition according to claim 1 , wherein R 2 is selected from C 6 to C 12 alkyl that is branched.
6. The composition according to claim 5 , wherein R 2 is 2-ethylhexyl.
7. The composition according to claim 1 , wherein R 1 is selected from C 7 alkyl that is saturated and unbranched.
8. The composition according to claim 1 , wherein R 1 is selected from C 9 alkyl that is saturated and unbranched.
9. The composition according to claim 1 , wherein R 1 is selected from C 10 alkyl that is saturated and unbranched.
10. The composition according to claim 1 , wherein said composition has a kinematic viscosity of about 15 cSt when measured at 40° C.
11. The composition according to claim 1 , wherein said composition has a kinematic viscosity of about 16 cSt when measured at 40° C.
12. The composition according to claim 1 , wherein said composition exhibits an iodine value (IV) of less than 10 cg/g.
13. The composition according to claim 10 , wherein said composition exhibits an iodine value (IV) of less than 5 cg/g.
14. The composition according to claim 1 , wherein said at least one estolide compound is derived from a process that comprises forming a covalent bond between an oxygen of a carboxylic group of at least one first fatty acid and a carbon of at least one site of unsaturation of at least one second fatty acid.
15. The composition according to claim 2 , wherein R 1 is selected from C 9 alkyl that is saturated and unbranched.
16. The composition according to claim 15 , wherein said composition has a kinematic viscosity of about 15 cSt when measured at 40° C.
17. The composition according to claim 3 , wherein R 1 is selected from C 10 alkyl that is saturated and unbranched.
18. The composition according to claim 17 , wherein said composition has a kinematic viscosity of about 16 cSt when measured at 40° C.
19. The composition according to claim 1 , wherein said composition exhibits a pour point of less than −50° C.
20. The composition according to claim 1 , wherein said composition exhibits a pour point of −50° C. to −60° C.