Catalytic processes for preparing estolide base oils
Provided herein are processes for preparing estolides and estolide base oils from fatty acid reactants utilizing catalysts. Further provided herein are processes for preparing carboxylic esters from at least one carboxylic acid reactant and at least one olefin.
1. A process of producing an estolide base oil comprising:
providing at least one first fatty acid reactant having at least one site of unsaturation, at least one second fatty acid reactant, and a triflate catalyst; and
oligomerizing the at least one first fatty acid reactant with the at least one second fatty acid reactant in the presence of the triflate catalyst and a Bronsted acid to produce an estolide base oil, wherein said oligomerizing comprises forming a covalent bond between an oxygen of a carboxylic group of the at least one second fatty acid reactant and a carbon of at least one site of unsaturation of the at least one first fatty acid reactant.
2. The process according to claim 1 , wherein the at least one first fatty acid reactant is selected from an unsaturated fatty acid or an unsaturated fatty acid oligomer.
3. The process according to claim 1 , wherein the at least one second fatty acid reactant is selected from a saturated fatty acid, an unsaturated fatty acid, a saturated fatty acid oligomer, or an unsaturated fatty acid oligomer.
4. The process according to claim 1 , wherein the triflate catalyst is selected from at least one of AgOTf, Cu(OTf) 2 , Fe(OTf) 2 , Fe(OTf) 3 , NaOTf, LiOTf, Yb(OTf) 3 , Y(OTf) 3 , Zn(OTf) 2 , Ni(OTf) 2 , Bi(OTf) 3 , La(OTf) 3 , or Sc(OTf) 3 .
5. The process according to claim 4 , wherein the triflate catalyst is selected from at least one of Fe(OTf) 3 , Bi(OTf) 3 , or Cu(OTf) 2 .
6. The process according to claim 4 , wherein the triflate catalyst is Bi(OTf) 3 .
7. The process according to claim 4 , wherein the triflate catalyst is Cu(OTf) 2 .
8. The process according to claim 4 , wherein the triflate catalyst is Fe(OTf) 3 .
9. The process according to claim 1 , wherein the oligomerizing takes place in the presence of microwave radiation.
10. The process according to claim 9 , wherein the oligomerizing is conducted in a microwave reactor.
11. The process according to claim 1 , wherein the Bronsted acid is selected from at least one of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, perchloric acid, triflic acid, or p-TsOH.
12. The process according to claim 1 , wherein the Bronsted acid comprises a solid-supported acid.
13. The process according to claim 12 , wherein the Bronsted acid comprises an acid-activated clay.
14. The process according to claim 12 wherein the Bronsted acid comprises an acid-activated montmorillonite clay.
15. The process according to claim 12 , wherein the Bronsted acid comprises an acidic mesoporous material.
16. The process according to claim 15 , wherein the Bronsted acid comprises a zeolite material.
17. The process according to claim 1 , wherein the oligomerizing is carried out at a temperature that is greater than 50° C.
18. The process according to claim 1 , wherein the oligomerizing is carried out at a pressure of less than 1 atm absolute.
19. The process according to claim 1 , further comprising esterifying the estolide base oil to provide an esterified estolide base oil.
20. The process according to claim 19 , wherein the esterifying is carried out in the presence of at least one alcohol and at least one esterification catalyst.
21. The process according to claim 20 , wherein the at least one esterification catalyst is selected from a Bronsted acid esterification catalyst or a Lewis acid esterification catalyst.
22. The process according to claim 21 , wherein the Bronsted acid esterification catalyst comprises a solid-supported acid.
23. The process according to claim 21 , wherein the Bronsted acid esterification catalyst comprises an acid-activated clay.
24. The process according to claim 21 , wherein the Bronsted acid esterification catalyst comprises an acid-activated montmorillonite clay.
25. The process according to claim 21 , wherein the Bronsted acid esterification catalyst comprises an acidic mesoporous material.
26. The process according to claim 21 , wherein the Bronsted acid esterification catalyst comprises a zeolite material.
27. The process according to claim 21 , wherein the Bronsted acid esterification catalyst is selected from at least one of hydrochloric acid, sulfamic acid, methylsulfamic acid, sulfuric acid, nitric acid, phosphoric acid, perchloric acid, triflic acid, or p-TsOH.
28. The process according to claim 21 , wherein the Lewis acid esterification catalyst is a triflate.
29. The process according to claim 28 , wherein the Lewis acid esterification catalyst is selected from at least one of AgOTf, Cu(OTf) 2 , Fe(OTf) 2 , Fe(OTf) 3 , NaOTf, LiOTf, Yb(OTf) 3 , Y(OTf) 3 , Zn(OTf) 2 , Ni(OTf) 2 , Bi(OTf) 3 , La(OTf) 3 , or Sc(OTf) 3 .
30. The process according to claim 29 , wherein the Lewis acid esterification catalyst is Bi(OTf) 3 .
31. The process according to claim 21 , wherein the oligomerizing triflate catalyst and the Lewis acid esterification catalyst are the same.
32. The process according to claim 21 , wherein the Lewis acid esterification catalyst is at least one metal compound selected from a titanium compound, a tin compound, a zirconium compound, or a hafnium compound.
33. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one titanium compound selected from TiCl 4 or Ti(OCH 2 CH 2 CH 2 CH 3 ) 4 .
34. The process according to claim 33 , wherein the Lewis acid esterification catalyst is Ti(OCH 2 CH 2 CH 2 CH 3 ) 4 .
35. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one tin compound selected from Sn(O 2 CCO 2 ), SnO, or SnCl 2 .
36. The process according to claim 35 , wherein the Lewis acid esterification catalyst is Sn(O 2 CCO 2 ).
37. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one zirconium compound selected from ZrCl 4 , ZrOCl 2 , ZrO(NO 3 ) 2 , ZrO(SO 4 ), or ZrO(CH 3 COO) 2 .
38. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one zirconium compound selected from ZrOCl 2 .8H 2 O or ZrOCl 2 .2THF.
39. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one hafnium compound selected from HfCl 2 or HfOCl 2 .
40. The process according to claim 32 , wherein the Lewis acid esterification catalyst is at least one hafnium compound selected from HfOCl 2 .2THF or HfOCl 2 .8H 2 O.
41. The process according to claim 19 , wherein the esterifying takes place in the presence of microwave radiation.
42. The process according to claim 41 , wherein the esterifying is conducted in a microwave reactor.
43. The process according to claim 1 , wherein said process is a continuous flow process.
44. The process according to claim 1 , further comprising recovering the triflate catalyst.
45. The process according to claim 44 , further comprising reusing the recovered triflate catalyst.
46. The process according to claim 44 , wherein the recovered triflate catalyst is reused for oligomerization.