Liquid fuel compositions

Abstract

The present invention provides a liquid fuel composition comprising: a) a base fuel suitable for use in an internal combustion engine; and b) one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group having formula (III): [Y—CO[O-A-CO] n -Z p ] m -X  (III) wherein Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group, n is from 1 to 100, m is 1 or 2, Z is an optionally substituted divalent bridging group, p is 0 or 1, and X is terminal acid group or a group carrying a terminal acid group, wherein the terminal acid group is selected from carboxylic acid, carboxymethyl, sulphate, sulphonate, phosphate and phosphonate.

1 . A liquid fuel composition comprising:
 a) a base fuel suitable for use in an internal combustion engine; and   b) one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group having formula (III):
   [Y—CO[O-A-CO] n -Z p ] m -X  (III) 
   wherein Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group, n is from 1 to 100, m is 1 or 2, Z is an optionally substituted divalent bridging group, p is 0 or 1, and X is terminal acid group or a group carrying a terminal acid group, wherein the terminal acid group is selected from carboxylic acid, carboxymethyl, sulphate, sulphonate, phosphate and phosphonate.   
     
     
         2 . The liquid fuel composition of  claim 1  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is at least 1 ppmw, based on the overall weight of the liquid fuel composition. 
     
     
         3 . The liquid fuel composition of  claim 2  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is in the range of from 10 ppmw to 20% wt, based on the overall weight of the liquid fuel composition. 
     
     
         4 . The liquid fuel composition of  claim 1  wherein X is a group of the formula -Z 1 -X 1 , wherein Z 1  is a bifunctional linking compound and X 1  is a terminal acid group selected from carboxylic acid, carboxymethyl, sulphate, sulphonate, phosphate and phosphonate. 
     
     
         5 . The liquid fuel composition of  claim 4  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is at least 1 ppmw, based on the overall weight of the liquid fuel composition. 
     
     
         6 . The liquid composition of  claim 5  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is in the range of from 10 ppmw to 20% wt, based on the overall weight of the liquid fuel composition. 
     
     
         7 . The liquid fuel composition of  claim 4  wherein Z 1  is a bifunctional linking compound selected from a polyamine, polyol, hydroxylamine, or a Z group. 
     
     
         8 . The liquid fuel composition of  claim 7  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is at least 1 ppmw, based on the overall weight of the liquid fuel composition. 
     
     
         9 . The liquid fuel composition of  claim 1  wherein the terminal acid group is in the free acid form. 
     
     
         10 . The liquid fuel composition of  claim 9  wherein the amount of the one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group present in the liquid fuel composition of the present invention is at least 1 ppmw, based on the overall weight of the liquid fuel composition. 
     
     
         11 . The liquid fuel composition of  claim 1  wherein the terminal acid group is in the form of a salt of the acid. 
     
     
         12 . The liquid fuel composition of  claim 1  wherein the base fuel is a gasoline. 
     
     
         13 . The liquid fuel composition of  claim 1  wherein the base fuel is a diesel fuel. 
     
     
         14 . A method of operating an internal combustion engine, which method involves introducing into a combustion chamber of the engine a liquid fuel composition of  claim 1 . 
     
     
         15 . A lubricating composition comprising:
 a) a base oil; and   b) one or more poly(hydroxycarboxylic acid) derivative having a terminal acid group having formula (III):
   [Y—CO[O-A-CO] n -Z p ] m -X  (III) 
   
       wherein Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group, n is from 1 to 100, m is 1 or 2, Z is an optionally substituted divalent bridging group, p is 0 or 1, and X is terminal acid group or a group carrying a terminal acid group, wherein the terminal acid group is selected from carboxylic acid, carboxymethyl, sulphate, sulphonate, phosphate and phosphonate.