坡缕石负载对甲苯磺酸催化合成柠檬酸三辛酯

Synthesis of Trioctyl Citrate Catalyzed by p-toluene Sulphonic Acid Supported on Palygorskite

利用回流蒸发吸附法制备了酸化坡缕石负载的对甲苯磺酸催化剂,以红外光谱、X-射线粉末衍射进行了表征.通过一系列单因素实验探讨了载体的酸化浓度,对甲苯磺酸在坡缕石上的负载量,催化剂用量,酸醇摩尔比和反应时间等因素对合成柠檬酸三正辛酯反应的影响.结果表明:以柠檬酸和正辛醇为原料,在150℃,酸醇摩尔比为1∶5,催化剂用量为0.8 g,反应1.5 h条件下,酯化率可达96.7%.催化剂性能较好,便于从反应体系中分离.

Catalyst, p-toluene sulphonic acid supported on acid activated palygorskite, is prepared via adsorption through reflux and evaporation; the resulted catalyst is characterized by FTIR , XRD spectroscopy. Several factors including the concentration of acid treated on palygorskite, the quantity of p-toluene sulphonic acid supported on the supporter, the amount of catalyst, the ratio of acid to alcohol and reaction times are discussed by means of single factor experiment to get the optimal reaction condition for the synthesis of trioctyl citrate. The yield could reach 96.7% as the molar ratio of citric acid to n-octyl alcohol is 1：5, the reaction time is 1.5 h, mass of catalyst is 0.8 g, the reaction temperature is at 150℃ and the amount of citric acid is 0. 025 mol. This kind of catalyst is relatively active and can be easily separated from the reaction system.