Estolide compositions exhibiting high oxidative stability

Abstract

Provided herein are estolide compositions having high oxidative stability, said compositions comprising at least one compound of formula: in which n is an integer equal to or greater than 0; m is an integer equal to or greater than 1; R 1 , independently for each occurrence, is selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; R 2 is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R 3 and R 4 , independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. Also provided herein are uses for the compositions and methods of preparing the same.

1 - 131 . (canceled) 
     
     
         132 . A composition comprising:
 a combination of (i) an estolide base oil having an acid value equal to or less than 0.5 mg KOH/g, and (ii) at least one antioxidant,
 wherein the combination exhibits a time of at least 600 minutes when tested in a rotating pressurized vessel oxidation test using ASTM Method 2272-11. 
   
     
     
         133 . The composition according to  claim 132 , wherein the estolide base oil comprises at least one estolide 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. 
       
     
     
         134 . The composition according to  claim 133 , wherein
 x is, independently for each occurrence, an integer selected from 0 to 14;   y is, independently for each occurrence, an integer selected from 0 to 14;   n is an integer selected from 0 to 8;   R 1  is an optionally substituted C 1  to C 22  alkyl that is saturated or unsaturated, and branched or unbranched; and   R 2  is an optionally substituted C 1  to C 22  alkyl that is saturated or unsaturated, and branched or unbranched,   wherein each fatty acid chain residue is unsubstituted.   
     
     
         135 . The composition according to  claim 134 , 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.   
     
     
         136 . The composition according to  claim 134 , wherein R 2  is an unsubstituted alkyl that is saturated. 
     
     
         137 . The composition according to  claim 136 , wherein R 2  is branched. 
     
     
         138 . The composition according to  claim 137 , wherein R 2  is selected from C 6  to C 12  alkyl. 
     
     
         139 . The composition according to  claim 138 , wherein R 2  is 2-ethylhexyl. 
     
     
         140 . The composition according to  claim 136 , wherein R 1  is a branched or unbranched alkyl that is saturated. 
     
     
         141 . The composition according to  claim 140 , wherein R 1  is unbranched. 
     
     
         142 . The composition according to  claim 132 , wherein the combination exhibits a time of at least 700 minutes when tested in a rotating pressurized vessel oxidation test using ASTM Method 2272-11. 
     
     
         143 . The composition according to  claim 132 , wherein the combination exhibits a time of at least 1000 minutes when tested in a rotating pressurized vessel oxidation test using ASTM Method 2272-11. 
     
     
         144 . The composition according to  claim 132 , wherein the composition consists essentially of the combination of the estolide base oil and the at least one antioxidant. 
     
     
         145 . The composition according to  claim 132 , wherein the at least one antioxidant comprises an amine antioxidant and/or a phenolic antioxidant. 
     
     
         146 . The composition according to  claim 145 , the estolide base oil has an acid value equal to or less than 0.2 mg KOH/g 
     
     
         147 . The composition according to  claim 133 , wherein the at least one antioxidant comprises an amine antioxidant and/or a phenolic antioxidant. 
     
     
         148 . The composition according to  claim 147 , the estolide base oil has an acid value equal to or less than 0.2 mg KOH/g 
     
     
         149 . The composition according to  claim 148 , wherein the at least one antioxidant comprises a diarylamine antioxidant. 
     
     
         150 . The composition according to  claim 149 , wherein the at least one antioxidant further comprises a hindered phenolic antioxidant. 
     
     
         151 . The composition according to  claim 145 , wherein the at least one antioxidant comprises 0.01 to 5 wt. % of the combination. 
     
     
         152 . The composition according to  claim 132 , wherein the composition further comprises at least one lubricating oil selected from one or more of a Group I oil, a Group II oil, a Group III oil, a polyalphaolefin, or a polyalkylene glycol. 
     
     
         153 . The composition according to  claim 152 , wherein the at least one lubricating oil comprises an oil soluble polyalkylene glycol. 
     
     
         154 . The composition according to  claim 134 , wherein x is, independently for each occurrence, an integer selected from 7 and 8. 
     
     
         155 . The composition according to  claim 154 , wherein y is, independently for each occurrence, an integer selected from 7 and 8. 
     
     
         156 . The composition according to  claim 154 , wherein y is 0 for each occurrence. 
     
     
         157 . The composition according to  claim 140 , wherein the at least one antioxidant comprises an amine antioxidant and/or a phenolic antioxidant. 
     
     
         158 . The composition according to  claim 157 , the estolide base oil has an acid value equal to or less than 0.2 mg KOH/g 
     
     
         159 . The composition according to  claim 158 , wherein the at least one antioxidant comprises a diarylamine antioxidant. 
     
     
         160 . The composition according to  claim 159 , wherein the at least one antioxidant further comprises a hindered phenolic antioxidant. 
     
     
         161 . The composition according to  claim 157 , wherein the at least one antioxidant comprises 0.01 to 5 wt. % of the combination.