Inhibitor Combination for Lithium Salt-Catalyzed Transesterification Process and Method for Removing Lithium Salt

Abstract

A process to form a composition comprising an asymmetrical polyene, the asymmetrical polyene comprising an “α,β unsaturated-carbonyl end” and a “C—C double bond end,” the process comprising: reacting an alkene- or polyene-containing alcohol with an alkyl ester of an α,β unsaturated carboxylic acid in the presence of at least the following components A) through C) to form a solution comprising an asymmetrical polyene: A) a lithium salt; B) a component selected from the group consisting of hydroquinone, an alkyl-substituted phenol, a substituted alkyl-substituted phenol, an alkyl-substituted hydroquinone, a substituted alkyl-substituted hydroquinone, and combinations thereof; and C) an N-oxyl-containing compound; wherein the “α,β unsaturated-carbonyl end” of the asymmetrical polyene is selected from the group consisting of structures a) through c), as described herein, and wherein the “C—C double bond end” of the asymmetrical polyene is selected from the group consisting of structures 1) through 17), as described herein.

1 . A composition comprising:
 A) an asymmetrical polyene with an “α,β unsaturated-carbonyl end” and a “C—C double bond end;”   B) less than 100 ppm, based on the total weight of the composition, of an inhibitor selected from the group consisting of 4-HT and derivatives thereof; and   C) less than 2000 ppm, based on the total weight of the composition, of MeHQ,   wherein the “α,β unsaturated-carbonyl end” of the asymmetrical polyene is selected from the group consisting of the following:   
       
         
           
           
               
               
           
         
          wherein R 1  is selected from H or a C 1 -C 6  alkyl; 
       
       
         
           
           
               
               
           
         
         wherein R 2  is selected from H or a C 1 -C 6  alkyl; R 3  is selected from H, CH 3 , or CH 2 CH 3 ; R 4  is selected from H, CH 3 , or CH 2 CH 3 ; and n is from 1 to 50; and 
       
       
         
           
           
               
               
           
         
       
       and
 wherein the “C—C double bond end” of the asymmetrical polyene is selected from the group consisting of the following: 
 
       
         
           
           
               
               
           
         
          wherein R5 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
          wherein R6 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
          wherein R7 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
          wherein m=1 to 20. 
       
     
     
         2 . The composition of  claim 1  comprising from 25 ppm to less than 100 ppm, based on the weight of the composition, of the inhibitor selected from the group consisting of 4-HT and derivatives thereof. 
     
     
         3 . The composition of  claim 1  comprising from 50 ppm to less than 2000 ppm, based on the weight of the composition, of MeHQ. 
     
     
         4 . The composition of  claim 1  further comprising less than 10 wt % unreacted alkene- or polyene-containing alcohol, based on the total weight of the composition. 
     
     
         5 . The composition of  claim 4  comprising from 2 wt % to less than 10 wt % unreacted alkene- or polyene-containing alcohol, based on the total weight of the composition, wherein the unreacted alkene- or polyene-containing alcohol is polypropylene glycol allyl ether. 
     
     
         6 . The composition of  claim 1  further comprising less than 10 wt % of Michael adducts, based on the total weight of the composition. 
     
     
         7 . The composition of  claim 1  further comprising a lithium salt. 
     
     
         8 . The composition of  claim 7 , wherein the lithium salt has the structure Li n X, wherein n is 1 or 2; and X is selected from the group consisting of hydroxide, oxide, halide, carbonate, bicarbonate, alkoxide, alkonate, alkenoate, phenoxide, sulfate, bisulfate, sulfonate, phosphate, phosphonate, perchlorate, and nitrate. 
     
     
         9 . The composition of  claim 7 , wherein the lithium salt has the structure Li n X, wherein n is 1 or 2; and X is selected from the group consisting of OH − , O −2 , a halide, OR − , CO 3   −2 , HCO 3   − , and R′CO 2   − ; wherein R is selected from a C1-C8 straight chain or branched alkyl group or from an aryl group; wherein R′ is selected from either a C1-C8 straight chain or branched alkyl group, or an aryl group, or a C1-C3 alkene group. 
     
     
         10 . The composition of  claim 7 , wherein the lithium salt is anhydrous lithium hydroxide. 
     
     
         11 . The composition of  claim 1  further comprising unreacted alkyl ester of an α,β unsaturated carboxylic acid. 
     
     
         12 . The composition of  claim 11 , wherein the unreacted alkyl ester of an α,β unsaturated carboxylic acid is methyl methacrylate. 
     
     
         13 . An asymmetrical polyene formed by reacting an alkene- or polyene-containing alcohol with an alkyl ester of an α,β unsaturated carboxylic acid in the presence of at least components A) through C) to form a solution comprising the asymmetrical polyene:
 A) a lithium salt, 
 B) a component selected from the group consisting of hydroquinone, an alkyl-substituted phenol, a substituted alkyl-substituted phenol, an alkyl-substituted hydroquinone, a substituted alkyl-substituted hydroquinone, and combinations thereof, and 
 C) an N-oxyl-containing compound, 
 wherein the asymmetrical polyene has an “α,β unsaturated-carbonyl end” selected from the group consisting of the following: 
 
       
         
           
           
               
               
           
         
         wherein R 1  is selected from H or a C 1 -C 6  alkyl; 
       
       
         
           
           
               
               
           
         
         wherein R 2  is selected from H or a C 1 -C 6  alkyl; R 3  is selected from H, CH 3 , or CH 2 CH 3 ; R 4  is selected from H, CH 3 , or CH 2 CH 3 ; and n is from 1 to 50; and 
       
       
         
           
           
               
               
           
         
          and 
         a “C—C double bond end” selected from the group consisting of the following: 
       
       
         
           
           
               
               
           
         
         wherein R5 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
         wherein R6 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
         wherein R7 is selected from H or C1-C6 alkyl; 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein m=1 to 20. 
       
     
     
         14 . The asymmetrical polyene of  claim 13 , wherein the asymmetrical polyene is polypropylene glycol allyl ether methacrylate (PPG AEMA).