POM-ILs催化剂的制备及其在合成聚混合二元酸乙二醇酯中的应用

Preparation of POM-ILs catalyst and its application in synthesis of polyglycol mixed dibasic acid ester

摘要:

制备了Keggin型单取代多金属氧酸盐离子液体催化剂(POM-ILs),利用红外光谱仪、热重分析仪、X射线衍射仪、场发射扫描电镜及X射线能谱仪对催化剂进行结构、热稳定性能、结晶结构、催化剂形貌、元素的表征与分析测试,并将其应用于催化混合二元酸二甲酯(DBE)与碳酸乙烯酯(EC)反应合成聚混合二元酸乙二醇酯,讨论不同催化剂的催化性能,并选取最优催化剂进行正交试验,探究该反应的最佳工艺条件。利用红外光谱仪、热重分析仪、差示扫描量热分析和凝胶渗透色谱分析对聚混合二元酸乙二醇酯进行结构表征、热稳定性能、热性能和分子量分布测定分析。结果表明,成功合成了聚混合二元酸乙二醇酯,且其主要性能也相近聚丁二酸乙二醇酯,在相同工艺条件下,锡单取代的锌钨酸盐离子液体催化剂[Bmim]6ZnW11SnO39(H2O)的催化性能最优。在最佳工艺条件下,聚混合二元酸乙二醇酯预聚物的收率达到50.19%,选择性可达到54.89%,探究缩聚反应的最佳时间为3.5 h,最佳温度为220 ℃,聚混合二元酸的数均分子量?Mn可达到14433,且具有良好的熔融加工性能和热稳定性能。
关键词:多金属氧酸盐；离子液体；尼龙酸；聚混合二元酸乙二醇酯；生物可降解聚酯
中图分类号:TQ323. 4???? 文献标识码:? A??? 文章编号:

Abstract:

Keggin-type monosubstituted polyoxometalate ionic liquid catalysts ( POM-ILs ) were prepared. The structure, thermal stability, crystal structure, catalyst morphology and elements of the catalysts were characterized and analyzed by infrared spectrometer, thermogravimetric analyzer, X-ray diffractometer, field emission scanning electron microscope and X-ray energy spectrometer. The catalysts were applied to catalyze the reaction of mixed dibasic acid dimethyl ester ( DBE ) and ethylene carbonate ( EC ) to synthesize polyglycol mixed dibasic acid ester. The catalytic performance of different catalysts was discussed, and the optimal catalyst was selected for orthogonal test to explore the optimal process conditions of the reaction.Structural characterization, thermal stability, thermal properties and molecular weight distribution determination of polyglycol mixed dibasic acid ester were analyzed using infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetric analysis and gel permeation chromatography.The structure characterization, thermal stability, thermal properties and molecular weight distribution of polyglycol mixed dibasic acid ester were analyzed by infrared spectrometer, thermogravimetric analyzer, differential scanning calorimetry and gel permeation chromatography.The results showed that the polyglycol mixed dibasic acid ester was successfully synthesized, and its main properties were similar to those of poly ( ethylene glycol succinate ). Under the same process conditions, the tin monosubstituted zinc tungstate ionic liquid catalyst [ Bmim ]6ZnW11SnO39 ( H2O ) had the best catalytic performance.Under the optimal process conditions, the yield of poly(ethylene glycol) mixed dibasic acid prepolymer reached 50.19%, and the selectivity could reach 54.89%, the optimal time to explore the polycondensation reaction was 3.5 h, and the optimal temperature was 220 ℃, and the number average molecular weight of poly(ethylene glycol) mixed dibasic acid), Mn, could reach 14,433, and the poly(ethylene glycol) mixed dibasic acid had good melt-processing properties and thermal stability properties.