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毕业论文网 > 毕业论文 > 化学化工与生命科学类 > 化学 > 正文

磁性材料固载化聚杂多酸性离子液体催化合成油酸乙酯的研究毕业论文

 2022-04-24 23:23:33  

论文总字数:24474字

摘 要

离子液体以其特有的物理和化学性质受到广泛关注,将它作为反应介质或催化剂进行均相催化反应,显示出较高的催化活性和选择性。但离子液体作为催化剂用量大、价格高及均相反应中催化剂和产物难分离等缺点限制了其广泛应用。为解决上述问题,本文制备了磁性材料固载化聚杂多酸性离子液体催化剂,并对其在酯化反应中的催化性能进行研究。

本文制备了超顺磁性的Fe3O4纳米颗粒,以含双键的硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)对磁性材料表面进行修饰,使其表面带有可进行自由基聚合的C=C双键(Fe3O4-MPS)。通过含有双键的酸性离子液体[SO3H-(CH2)3-VIM][HSO4]、二乙烯基苯在磁性材料Fe3O4-MPS表面进行共聚反应,在通过阴离子交换反应将磷钨酸修饰到聚离子液体单元上,制备可磁性分离的固载型聚杂多酸性离子液体催化剂。

对催化剂的组成与结构进行XRD、FT-IR、SEM、VSM等表征,同时以油酸和乙醇酯化反应作为评价体系,考察反应温度、反应时间、醇酸摩尔比及催化剂用量对油酸转化率的影响。结果表明:离子液体成功聚合并固载到载体上,Fe3O4全部或部分嵌入到聚离子液体层中。催化剂具有超顺磁性,饱和磁化强度达14.3emu/g。在较佳的反应条件下反应温度100℃、反应时间4h、催化剂用量10wt%、醇酸比12:1,油酸转化率可达89.5%,表明该催化剂在油酸/乙醇反应中具有较高的催化活性。反应结束后催化剂在外加磁场作用下可实现快速分离。

关键词:聚离子液体 磁性材料 固载 油酸乙酯

Preparation of magnetic material supported poly (phosphotungstate-

based ionic liquid) catalyst for Ethyl Oleate Production

Abstract

Recently, Ionic liquids (ILs) have attracted wide attentions in catalytic field as environmental friendly catalysts and green solvents due to their unique physical and chemical properties. High catalytic activity and selectivity can be obtained when ILs are applied. However, the large dosage of catalyst, high viscosity, and difficult product separation restrict their applications. To solve the problems, magnetic material supported poly (phosphotungstate-based ionic liquid) catalyst was prepared and applied for the synthesis of ethyl oleate.

In this paper, superparamagnetic Fe3O4 nanoparticle was prepared and γ-methacryloyloxy trimethoxysilane was used to modify Fe3O4 with the purpose of offering vinyl. Vinyl group functionalized acidic ionic liquid [SO3H-(CH2)3-VIM][HSO4] was immobilized on the surface of vinyl-Fe3O4 by copolymerization method with divinylbenzene as crosslinking agent. Then phosphotungstic acid was modified to the poly ionic liquid layers by anion exchange and magnetic material supported poly (phosphotungstate-based ionic liquid) catalyst was prepared.

The samples were characterized by XRD, FT-IR, SEM and VSM. The results indicated that the poly ionic liquid layers were successfully immobilized on the supported with Fe3O4 fully or partly embedded. The catalyst showed superparamagnetic behavior with high magnetization (14.3 emu/g). The effects of reaction temperature, reaction time, ethanol to oleic acid molar ratio, and catalyst dosage on esterification of oleic acid with ethanol were investigated. The suitable reaction conditions for the synthesis of ethyl oleate were as follows: reaction temperature 100℃, reaction time 4h, n (ethanol)/n (oleic acid) 12:1, and catalyst dosage 10wt%. Under above conditions, the conversion of oleic acid reached to 89.5%. The as-prepared catalyst was efficient for the synthesis of ethyl oleate, with the properties of convenient magnetic separability and good reusability.

Key words: Poly Ionic liquid; Magnetic Material; Support; Esterification

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 引言 1

1.2 离子液体的概述 2

1.2.1 离子液体的发展 2

1.2.2 离子液体的制备 3

1.2.3 离子液体的应用 4

1.3固载化离子液体的概述 5

1.3.1固载化离子液体的制备 6

1.3.2 固载化离子液体的应用 9

1.4 研究意义与内容 10

1.4.1研究意义 10

1.4.2研究内容 10

第二章 实验部分 12

2.1 试剂与仪器 12

2.1.1 实验试剂 12

2.1.2 主要仪器 13

2.2 催化剂的制备 13

2.2.1 离子液体的制备 13

2.2.2 磁性材料的制备 14

2.2.3 固载化离子液体的制备 14

2.3 表征及分析方法 15

2.3.1 表征方法 15

2.3.2 表征分析方法 16

第三章 磁性材料固载化杂多离子液体催化剂用于油酸酯化的研究 18

3.1催化剂表征分析 18

3.1.1 XRD分析 18

3.1.2 FT-IR分析 19

3.1.3 SEM分析 20

3.1.4 VSM分析 20

3.2固载化离子液体催化油酸乙酯性能研究 21

3.2.1 实验过程与步骤 21

3.2.2 催化性能评价 21

3.2.3 重复使用性能研究 25

第四章 结论与展望 26

4.1 结论 26

4.2 展望 26

参考文献 28

致 谢 31

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