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制备了聚咪唑-环氧氯丙烷离子液体,通过碱交换合成了碱性聚合离子液体,用红外、核磁、凝胶色谱法、电位滴定等手段进行表征,结果表明该离子液体催化剂聚合度较高,相对分子质量分布较窄,其OH-交换率大于95%.该离子液体对芳香醛与酮类的Claisen-Schmidt缩合反应有着良好的催化性能,苯甲醛与丙酮在25℃下,醛酮比为1∶4,在2.5 mol/L的醛溶液中,添加质量分数为2%的催化剂反应仅10 h即可达到99%的产率,在超声条件下反应4 h即可达到90%的收率,且该碱性离子液体经5次回收重复利用,其产率保持在90%以上.该催化剂在低添加量下具有较高的催化活性和较好的重复使用性能.
Polyimidazole - epichlorohydrin ionic liquids were prepared. Alkaline polymeric ionic liquids were synthesized by alkali exchange and characterized by IR, NMR, gel permeation chromatography and potentiometric titration. The results showed that the polymerization degree of the ionic liquid catalyst was high , The relative molecular weight distribution is narrow, and the OH-exchange rate is more than 95% .The ionic liquid has good catalytic performance for the Claisen-Schmidt condensation of aromatic aldehydes and ketones. The ratio of aldehydes / ketones Is 1: 4. In the 2.5 mol / L aldehyde solution, the catalyst with 2% mass fraction can reach 99% yield in 10 h, and the reaction can reach 90% in 4 h under ultrasonic condition Rate, and the basic ionic liquid was recycled after 5 recovery, the yield was maintained above 90%. The catalyst has high catalytic activity and better reusability at low loadings.