环状碳酸酯的固载型离子液体催化合成

通过烷基化反应和简单的一锅法将醇胺离子液体(TEA)嫁接到氯甲基聚苯乙烯(PS-Cl)微球上，将形成的嫁接型离子液体催化剂(PS-TEA]I)用于催化CO₂和环氧化物生成环状碳酸酯的反应. 采用傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)表征催化剂的结构和形貌，采用X射线光电子能谱(XPS)、元素分析(EA)和热重分析(TGA)研究了醇胺离子液体的嫁接量和热稳定性. 在环加成反应中，该催化剂无需溶剂和助催化剂，在催化剂用量为0.10 g、温度为120 ℃、CO₂压力为2 MPa以及反应时间为4 h的条件下，碳酸丙烯脂(PC)的产率达到93.30%，并且反应后容易分离，可重复使用. 最后提出了羟基形成的氢键可激活环氧化物和I-亲核进攻促进开环的反应机理.

The Synthesis of Cyclic Carbonate Catalyzed by Immobilized Ionic Liquid

The alcohol amine ionic liquid (TEA) was grafted onto chloromethyl polystyrene (PS-Cl) microspheres through alkylation reaction and the simple one-pot method and the resulting ionic liquid-supported catalyst (PS-TEA]I) was used to catalyze the formation of cyclic carbonates from carbon dioxide and epoxides. The structure and morphology of the catalyst were characterized with the Fourier transform infrared spectroscopy (FT-IR) and the scanning electron microscope (SEM). The grafting amount and the thermal stability of alcohol amine ionic liquids were studied with the X-ray photoelectron spectroscopy (XPS), the elemental analysis (EA) and the thermogravimetric analysis (TGA). In the cycloaddition reaction, the catalyst did not require solvents and co-catalysts. Under the experimental conditions of catalyst dosage of 0.10 g, 120 ℃ temperature, 2 MPa CO₂ pressure and 4 h reaction time, the yield of propylene carbonate (PC) reached 93.30%. It was easy to separate after the reaction and could be reused. The reaction mechanism of hydrogen bond formed with hydroxyl activating epoxide and I- nucleophilic attack to promote ring opening was finally proposed.