Study On Synthesis Of Benzyl Benzoate And Dynamics By Microwave Radiation

In this paper, benzyl acetate acid was produced from benzoic acid and benzyl alcohol under microwave radiation, using sodium acid sulfate, amino sulfonic acid and p-toluenesulfonic acid as catalysts. The effects of reaction temperature, the amount of catalysts, the reaction time, and the mole ratio of the raw material were compared. The results showed that the activity of p-toluenesulfonic acid was much higher than that of the amino sulfonic acid and hydrogen sulfate sodium.In addition, benzyl acetate acid was synthesized under conventional oil bath heating, using p-toluenesulfonic acid as catalyst. The effects of the reaction temperature, the amount of catalysts, the reaction time and the mole ratio of the raw material were investigated. The optimum conditions were concluded that: reaction temperature 150℃, the amount of p-toluenesulfonic acid 1.00 g, reactants benzoic acid 0.10 mol, alcohol-acid molar ratio for 4.0:1, and reaction time 140 min.Design four factors of three level orthogonal tests, p-toluene sulfonic acid as catalyst , synthesized benzyl benzoate respectively under in microwave radiation and routine oil bath heating, and the reaction process conditions were quadratic optimization, get the optimization under microwave irradiation process conditions as follows: reaction temperature 155℃, radiation time 30 min, P-toluene sulfonic acid dosage 1.20 g, reactants benzoic acid 0.10 mol, Alcohol-acid molar ratio 4.0:1, average yield can reach 94.52%. P-toluene sulfonic acid dosage and microwave radiation time have great influence on reaction yield; the optimization under conventional oil bath heating: reaction temperature 150℃, reaction time140 min, P-toluene sulfonic acid dosage 1.00 g, Alcohol-acid molar ratio 4.0:1, average yield can reach 96.37%. Alcohol-acid mole ratio has great influence on reaction yield. It turned out that: microwave can accelerated reaction, greatly shorten the reaction time, improved the reaction rate.In this paper the reaction kinetics of benzyl benzoate was discussed. In no catalyst cases, benzoic acid concentration didn't change with the reaction time increased, almost no esterification reaction occurring; In p-toluene sulfonic acid as catalyst, discussed reaction rate constant under different temperature, compared the activation energy and exponential factor under microwave radiation and conventional oil bath heating, get the activation energy under microwave radiation is three-tenths of that under conventional oil bath heating, and the exponential factor reduced greatly. Reaction kinetics research shows, microwave can accelerate the esterification reaction, it embodies the thermal and a thermal effect of microwave.