磺化交联壳聚糖树脂固体酸催化剂的制备及表征  

Preparation and characterization of sulfonated crosslinked chitosan resin as solid acidic catalyst

作　　者：李俊宏[1] 徐玉婷[1] 唐成黎[1] 刘雄[1] 谭芸妃[1] 董立春[1] 

机构地区：[1]重庆大学化学化工学院,重庆400044

出　　处：《化工学报》2013年第5期1635-1641,共7页CIESC Journal

基　　金：国家自然科学基金项目(21176270;51272296);中央高校基本科研业务费科研专项'研究生科技创新基金'项目(CDJXS10221140;CDJXS11221169);大学生国家创新基金项目(CDJXS10220006)~~

摘　　要：壳聚糖是自然界的第二大天然有机物甲壳素的脱乙酰产物,具有来源丰富、环境友好的优点。壳聚糖分子同时含有活泼的氨基和羟基,可通过烷基化、酯化、希夫碱等反应进行化学修饰生成具有各种不同新型结构和功能的衍生物[1]。近年来壳聚糖在催化领域的应用受到了越来越多的关注,Crosslinked chitosan resins（CCRs）with different crosslinking degrees were synthesized by using the inverse emulsion method and glutaraldehyde as crosslinking agent,and then sulfonated at-5℃ with concentrated H2SO4 as sulfonation agent.The properties and application of obtained sulfonated crosslinked chitosan resins（SCCRs）as solid acidic catalysts were studied.IR analysis showed that sulfonation of CCR occurred at both C2 amino groups and C6 secondary hydroxyl groups.Sulfur content measurements demonstrated that the higher the crosslinking degree of the SCCR,the larger the sulfonation rate of its C6 hydroxyl groups.The acidic sites in SCCR including C6-O and C2-N sulfate groups were all weak acidic sites.The acid content of SCCR was much higher than chitosan sulfate reported in the literature,which was prepared by direct sulfonation of chitosan without pre-crosslinking.High-temperature treatment verified that crosslinking improved the thermostability of SCCR.The SCCR with a higher crosslinking degree had better mass retention rate as well as larger sulfur retention rate.The catalytic activity and repeatability of SCCR as solid acidic catalysts were verified by testing its application in the synthesis of tributyl citrate from citric acid and butanol.The results showed that esterification rate of citrate acid could reach 94.8% when SCCR with a 100% crosslinking degree was used,and esterification rate could keep above 92% by repeated use of the SCCR for 6 times.Comparison with chitosan sulfate demonstrated that SCCR was a much better solid acidic catalyst and had a promising application prospect.

关 键 词：交联壳聚糖 磺化交联壳聚糖树脂 固体酸催化剂 酸量 热稳定性 

分 类 号：TQ426.62[化学工程]