甲磺酸盐的制备及其催化合成丁酸丁酯

Preparation of Methanesulfonates and Its Catalytic Activity in Esterification of Butyric Acid with n-Butyl Alcohol

以甲磺酸和金属氧化物为原料直接反应制备了甲磺酸钕、甲磺酸铕、甲磺酸镧、甲磺酸铜、甲磺酸锌5种甲磺酸盐催化剂,用于催化丁酸与正丁醇的酯化反应合成丁酸丁酯。采用傅里叶变换红外光谱和热重分析方法对甲磺酸钕催化剂的结构进行了表征。考察了n(正丁醇)∶n(丁酸)、催化剂用量、带水剂用量、反应时间对酯化反应的影响。实验结果显示,甲磺酸钕催化剂的活性最高、不易水解、易分离、无腐蚀性、重复使用性能好,明显优于传统的硫酸催化剂。最佳酯化条件:n(正丁醇)∶n(丁酸)=1.3,甲磺酸钕催化剂用量0.64%(以丁酸计的摩尔分数),带水剂环己烷用量5mL,回流反应2.0h。在此条件下,酯化率可达到99.1%。

Methanesulfonates of neodymium, europium, lanthanum, copper and zinc were synthesized from methane sulfonic acid and metallic oxides, and were used as catalysts in esterification of butyric acid with n-butyl alcohol. Neodymium methane sulfonate was characterized by means of FTIR and TGA. Effects of n （ n-butyl alcohol） ： n （ butyric acid）, catalyst dosage, dosage of cyclohexane as water entrainer and reaction time on esterification were investigated. Among the obtained metallic methane sulfonates neodymium methane sulfonate exhibited the highest catalytic activity in esterification, non corrosiveness and hard to be hydrolyzed, and could be reused by simple separation after reaction. Catalytic activity of the catalyst is obviously higher than that of conventional sulfuric acid. Under optimum conditions ： n （ n-butyl alcohol ） ： n （ butyric acid） 1.3, catalyst dosage （ mole fraction based on butyric acid） 0.64%, refluxing reaction time 2.0 h, cyclohexane as water entrainer 5 mL, esterification rate of butyl butyrate can reach 99.1%.