【摘要】 用3-氨丙基三甲氧基硅烷对硅胶进行改性,然后负载磷钨酸,制备了改性硅胶负载磷钨酸催化剂,并进行红外FT-IR分析以及热重分析。考察了改性硅胶与活化硅胶对磷钨酸的负载量以及它们催化合成柠檬酸三丁酯(TBC)的重复利用效果,结果表明:改性硅胶与活化硅胶的最大负载量分别为44.7%和16.8%,将此两种催化剂重复使用三次,平均产率分别91.1%和23.7%。设计了三因素三水平的正交试验,得到最佳反应条件:改性硅胶负载磷钨酸催化剂2.5g(负载量为43.5%),反应4h,(n柠檬酸:n正丁醇)为1:4,反应温度为140℃。产率为92.1%。更多还原

【Abstract】 The catalyst supported phosphotungstic acid(PA)is successfully synthesized using 3-(Aminopropyl)trimethoxyl silane to modify silica gel.The structure of catalyst was identified by means of IR and TG-DTG.The different of the supported quantity and the yield between modified silica gel and silica gel was obtained as follows:the supported quantity of modified silica gel 44.7%t,the other one 16.8%;The average yield of product using modified silica gel catalyst 91.1%,the other one 23.7%.The effects of reaction conditions on the rate of yield were investigated by three-factor orthogonal experiments.The optimum reaction conditions were obtained as follows:mass of catalyst 2.5g(supported quantity 43.5%),reaction time 4h,citric acid to n-butanol 1:4(mole)and reaction temperature 140℃.The percentage of average yield can reach to 92.1%under the optimum conditions.更多还原