Study of the Perfluorosulfonic Acid Resin Catalyst for the Synthesis of Tributyl Citrate under Microwave Irradiation

The tributyl citrate has been synthesized by citric acid and n-butyl alcohol catalyzed by rejected perfluorosulfonic acid resin under microwave irradiation.The author has also examined the synthetic conditions with perfluorosulfonic acid resin as catalyst.Under the microwave irradiation,the result also shows that the ester yield is 93.9% under the optimum operation conditions: the molar ratio of n-butyl alcohol to lactic acid is 6:1;the amount of catalyst is 0.315g,the reaction time is 40min and power of microwave irradiation is 500W.The catalyst is easy to be recovered and can be reused for many times.After six times,the ester yield is also over 90%.