微波辐射下活性炭负载磷钨酸催化合成没食子酸正丁酯

Synthesis of n-butyl gallate catalyzed by activated carbon supported phosphotungstic acid under microwave irradiation

采用微波辐射方法,以没食子酸和正丁醇为原料,活性炭负载磷钨酸为催化剂合成没食子酸正丁酯(BG),研究了不同磷钨酸负载量的催化剂的催化性能和催化剂的循环利用催化性能,并考察了微波辐射功率、催化剂用量、酸醇摩尔比、反应温度、反应时间对BG产率的影响。通过单因素实验及响应面法优化BG合成工艺条件,对产物进行了红外光谱表征。结果表明:负载量26.89%的催化剂催化性能较好,催化剂可多次重复使用; BG合成最佳工艺条件为没食子酸用量0.05 mol、微波辐射功率400 W、催化剂用量1.02 g(磷钨酸的负载量为26.89%)、酸醇摩尔比1∶11、反应温度127℃、反应时间34 min,在此条件下BG产率可达89.96%;红外光谱表征结果表明所得产物为没食子酸正丁酯。

The n-butyl gallate was prepared by microwave irradiation method with gallic acid and n-butyl alcohol as raw materials and activated carbon supported phosphotungstic acid as catalyst.The catalytic performance of catalysts with different loads of phosphotungstic acid and its reusability were studied.The effects of microwave irradiation power,dosage of catalyst,molar ratio of gallic acid to n-butyl alcohol,reaction temperature and reaction time on the yield of n-butyl gallate were investigated.The synthesis conditions of n-butyl gallate were optimized by single factor experiment and response surface methodology,and the product was characterized by infrared spectroscopy.The results showed that the catalytic performance of catalyst with 26.89% loads of phosphotungstic acid was good,and the catalyst could be reused for many times.The optimal synthesis conditions were obtained as follows： dosage of gallic acid0.05 mol,microwave irradiation power 400 W,dosage of catalyst 1.02 g（ phosphotungstic acid load26.89% ）,molar ratio of gallic acid to n-butyl alcohol 1∶ 11,reaction temperature 127 ℃ and reaction time 34 min.Under these conditions,the yield of n-butyl gallate reached 89.96% .The product was characterized as n-butyl gallate by infrared spectroscopy.