Nafion修饰炭基固体酸的制备及其催化四氢呋喃聚合性能

发布时间：2018-10-10 14:05

【摘要】：聚四氢呋喃是含两个羟基官能团的聚醚二醇,经催化四氢呋喃单体聚合而成,分子呈线性结构。平均分子量约2000的聚四氢呋喃主要用于合成氨纶的重要原料。聚四氢呋喃工业化生产工艺,常采用发烟硫酸、乙酸酐-高氯酸或氟磺酸作引发剂促使四氢呋喃发生聚合,但此类工艺存在腐蚀设备和后处理复杂等严重的后续处理问题。为了克服均相催化的缺限,研究者开始对聚合四氢呋喃的催化剂材料进行深入探讨。本文通过制备Nafion修饰炭基固体酸并进行表征,研究其对四氢呋喃聚合的催化性能,揭示所制固体酸催化剂结构、织构及酸碱性等对材料催化四氢呋喃聚合的影响规律。本论文主要从以下两个方面开展工作:(1)Nafion修饰葡萄糖炭基固体酸的制备及其催化THF聚合;(2)甲壳质掺杂Nafion-炭基固体酸的制备及其催化THF聚合。围绕以上两方面,我们首先研究Nafion修饰葡萄糖炭基固体酸制备及催化THF聚合。探讨不同Nafion含量,不同焙烧温度对催化四氢呋喃聚合的影响。然后引入甲壳质通过水热合成法、模板法、浸渍法制备甲壳质掺杂Nafion-炭基固体酸催化剂并探讨其对THF聚合的催化作用。对所制的催化剂进行表征:经过X射线衍射(XRD)、红外光谱(FT-IR)以及酸滴定法等得出结论,Nafion修饰葡萄糖炭基固体酸催化剂中具有磺酸基(-SO3H)且属于无定形炭类型。当Nafion溶液负载量增大时,酸量增加,聚四氢呋喃的收率增高趋于平衡,相对分子量降低。而且温度的升高也引起了酸量的减小,聚四氢呋喃收率增多而分子量下降。葡萄糖/壳粉用量的比例增多,聚四氢呋喃的收率增加,分子量增加。但前提是壳粉用量不大于葡萄糖用量。且加入壳粉比未加壳粉的催化剂对四氢呋喃聚合反应具有更好的催化活性,聚合物的收率更高。得到结论甲壳质是调节Nafion修饰葡萄糖炭基固体酸酸性的重要方法。
[Abstract]:Poly (tetrahydrofuran) is a polyether diol with two hydroxyl functional groups, which is synthesized by catalytic polymerization of tetrahydrofuran monomer. Polytetrahydrofuran with an average molecular weight of about 2000 is mainly used as an important raw material for the synthesis of spandex. In the industrial production process of polytetrahydrofuran, fuming sulfuric acid, acetic anhydride perchloric acid or fluorosulfonic acid are often used as initiators to promote the polymerization of tetrahydrofuran, but this process has serious problems such as corrosion equipment and complex post-treatment. In order to overcome the lack of homogeneous catalysis, researchers began to study the catalyst materials of polymerized tetrahydrofuran. In this paper, Nafion modified carbon-based solid acid was prepared and characterized to study its catalytic performance for tetrahydrofuran polymerization. The effects of structure, texture and acid-base of the solid acid catalyst on the catalytic activity of tetrahydrofuran polymerization were revealed. The main work of this thesis is as follows: (1) preparation of Nafion modified glucose carbon-based solid acid and its catalytic THF polymerization; (2) preparation of chitin doped Nafion- carbon-based solid acid and its catalytic THF polymerization. Around the above two aspects, we first studied the preparation of Nafion modified glucose carbon-based solid acid and its catalytic polymerization of THF. The effect of Nafion content and calcination temperature on the polymerization of tetrahydrofuran was studied. Then chitin was used to prepare chitin doped Nafion- carbon-based solid acid catalyst by hydrothermal synthesis template method and impregnation method and its catalytic effect on THF polymerization was discussed. The catalyst was characterized by X-ray diffraction (XRD), infrared spectroscopy (FT-IR) and acid titration. It was concluded that Nafion modified glucose carbon-based solid acid catalyst has sulfonic group (- SO3H) and belongs to amorphous carbon type. When the loading amount of Nafion solution increases, the acid content increases, the yield of polytetrahydrofuran tends to balance, and the relative molecular weight decreases. The increase of temperature also led to the decrease of acid content, the yield of polytetrahydrofuran increased and the molecular weight of polytetrahydrofuran decreased. The yield of polytetrahydrofuran increased and the molecular weight of polytetrahydrofuran increased with the increase of the ratio of glucose to shell powder. But the premise is that the amount of shell powder is no more than the amount of glucose. The addition of shell powder has better catalytic activity and the yield of polymer is higher than that of the catalyst without shell powder in the polymerization of tetrahydrofuran. Conclusion chitin is an important method to regulate the acidity of carboxylic acid modified by Nafion.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O633.5

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