甲烷磺酸盐的合成及其对酯化反应的催化性能

Synthesis and characterization of methane sulfonates and their catalytic activities for esterification

合成了甲烷磺酸镁、铝、钙、亚铁、钴、镍、铜、锌、钡、镧、亚铈、镨、钕等13种盐,并用热重和红外对其进行表征。在醇酸摩尔比1.1∶1、催化剂用量0.25%(以酸量计)、摩尔反应时间2.5h、反应温度为80～85℃、环己烷2.5ml作为带水剂的条件下,考察了甲烷磺酸盐催化合成乙酸与正丁醇酯化反应的催化活性。其中甲烷磺酸镧、铜、钙的催化活性较好,酯化率可达90.0%以上,远远高于其他路易斯酸。还考察了甲烷磺酸铜、甲烷磺酸钙、甲烷磺酸锌的重复使用性,结果表明,这三种盐经过简单的相分离就可重复使用,稳定性良好。

Methane sulfonates of magnesium, aluminum, calcium, ferrous iron, cobalt, nickel, copper, zinc, barium, lanthanide, cerous cerium, praseodymium and neodymium were synthesized and characterized by TGA and FTIR. Catalytic activity of the methanesulfonates was studied and compared with other Lewis acids under the following condition : n-butanol-to-acetic-acid molar ratio=1.1/1, catalyst loading=0.25% (molar percentage of acetic acid), reaction time 2.5 h, 80-85 ℃ and 2.5 ml cyclohexane as water-carrying agent. The experimental results showed that methanesulfonates of lanthanide, copper, calcium exhibited the highest catalytic activity , with butyl acetate yield of over 90.0%. Methanesulfonate of copper, calcium, zinc can be reused by simple phase-separation without remarkable loss of catalytic activity.