CATALYTIC SYNTHESIS OF ISOBUTYL GALLATE BY IONIC LIQUID AND ITS OXIDATION RESISTANCE

摘要

The factors affecting the synthesis of isobutyl gallate by gallic acid and isobutyl alcohol and its oxidation resistance were studied by using butyl-pyridine bisulphate ionic liquid as a catalyst. The single factor analysis showed that the reaction conditions of the highest esterification rate were as follows: molar ratio of alcohol to acid 40:1, reaction temperature 80 degrees C, catalyst amount 6% and reaction time 4 h which is found as the optimum reaction condition. Under this condition the esterification rate was 92.63%. Analysis of range of the orthogonal experiment showed that the order of affecting factors were the following: reaction temperature > amount of catalyst > reaction time > molar ratio of alcohol to acid. Analysis of variance of the orthogonal experiment showed that level change of the four factors including molar ratio of alcohol to acid A, reaction time B, reaction temperature C and amount of catalyst D had no significant influence on the esterification rate. The results also showed that isobutyl gallate has a good oxidation resistance to vegetable oil and biodiesel.