【作者】 邓芳；

【导师】 魏俊发；

【作者基本信息】 陕西师范大学 ， 有机化学， 2006， 硕士

【摘要】 环氧大豆油在塑料、涂料、橡胶等工业上有着广泛的用途,它对光、热有良好的稳定作用,且相容性好、挥发性低、迁移性小,是聚氯乙烯以及其它含卤高聚物重要的增塑剂兼稳定剂。与目前市场上的主要增塑剂邻苯二甲酸二辛酯相比较,它的突出优点就是无毒、耐热和耐光性能好,可作为食品、药物的包装材料以及玩具及家庭装饰材料的助剂。环氧大豆油的原料为可再生性资源,且价格比邻苯二甲酸二辛酯低。在石化资源价格不断上涨并且日益枯竭的今天,环氧大豆油的研究与开发尤为重要。 论文的第一部分介绍了环氧大豆油的合成现状,指出:环氧大豆油的现行生产方法主要是在酸催化下,用有机过酸对大豆油进行环氧化。有机过酸法合成环氧大豆油工艺成熟,得到的产品环氧值较高。然而有机过酸不稳定,容易分解,在加热时易爆炸且对人体有害,反应生成大量含稀酸的废水,污染严重。同时反应使用的强酸性催化剂会严重腐蚀设备,加深产品的色泽,降低产品质量。因此,如何避免过酸介入而引起的一系列问题,使环氧化工艺更加绿色化便成为本论文的选题主旨。 第一部分还综述了以过氧化氢为氧源的烯烃催化环氧化体系的研究进展,重点介绍了目前在烯烃环氧化研究中比较活跃的几类催化剂,如:甲基三氧化铼、金属卟啉、钨配合物等。比较了各种催化环氧化体系的反应条件以及在烯烃环氧化反应中的收率与选择性,同时指出了各类催化剂的优缺点、应用现状及前景。 综合考虑不同催化体系的优缺点和合成方法在工业中的实用性,结合本实验室在绿色氧化方面所取得一些成果,本论文设计在无羧酸参与的条件下,以过氧化氢为氧源,以钨类化合物为催化剂,实现大豆油催化环氧化为环氧大豆油。 在第二部分中,合成了一系列含钨的化合物,并使用它们对大豆油进行催化环氧化实验。通过核磁共振、红外光谱等对产物结构进行了表征,同时根据国标方法对产物的酸值、环氧值、碘值等进行了测定。研究并讨论了催化剂的种类及用量、溶剂、体系pH、反应时间、反应温度等因素对环氧化反应的影响,优化了反应条件。结果表明,无羧酸条件下直接使用过氧化氢作氧源可以实现大豆油的环氧化,得到的产品色泽浅,质量好。以WO₄^2-/PO₄^3-/CH₃(C₈H₁₇)₃NHSO₄为催化剂,乙酸乙酯作溶剂,在60℃和pH=2条件下反应7h可以获得质量满意的产品,其酸值、环氧值及碘值分别为:0.30mgKOH/100g、6.28%、5.80g I₂/100g,均达到国家一级品的要求。本方法避免了使用有机羧酸,有效的解决了过酸介入而更多还原

【Abstract】 Epoxidized soybean oil (ESBO) has been used for many commercial applications, e.g. as plasticizers and stabilizers in chlorine containing resins, as additives in lubricants, as components in thermosetting plastics and so on. It shows excellent promise as inexpensive renewable materials for industrial application. Compared with the main plasticizer dioctylphthalate in the market nowadays, it is not toxic and has good stability to light and heat. It can be used to synthesize the packing materials for food and medicine. With unceasingly rise in prices of petrochemicals, which are drying up day by day, it is especially important to research and develop ESBO.In the first part, the actuality of the synthesis of ESBO at present is summarized. The current method to produce ESBO is epoxidation of soybean oil (SBO) with peroxy-carboxylic acids catalyzed by acidic catalysts. However, the peroxy-carboxylic acids are harmful to our human beings and not stable, which can easily decompose when heated. Moreover, the acidic catalysts may damage the experimental instruments and cause the worse quality of the product. Thus, our research focus on how to avoid the problem caused by using peroxy-carboxylic acids and to make the epoxidation technique cleaner.The recent development on the epoxidation of alkenes using hydrogen peroxide as oxidant in different catalytic systems is also reviewed in this part. Several important kinds of catalysts are discussed, such as methyltrioxorhenium, metal porphyrins, tungsten-based compounds and so on. The yields and selectivities in different catalytic systems are summarized, and the advantages and disadvantages of them are evaluated as well.Considering the advantages and disadvantages of different catalytic systems, the practicability of synthetic method in industry, as well as some important efforts in green oxidation achieved in our laboratory, in this thesis, ESBO is synthesized by hydrogen peroxide under carboxylic acid-free condition using tungsten-based compounds as catalysts.In the second part, a series of tungsten-based catalysts were synthesized and used in the epoxidation of SBO. The chemical structure of the synthesized ESBO was characterized by ]H NMR, I3C NMR and FT-IR spectroscopy. Furthermore, the acid value, epoxy value and iodine value were examined according to the China National Standard. The effects of catalysts, reaction time, temperature, pH and solvents on the epoxidation were also discussed. The experimental results showed that ESBO could be successfully synthesized. The optimum reaction condition was achieved using WO427PO437 CH3(C8H17)3NHSO4 as catalyst and ethyl acetate as solvent at 60 °C for 7 h, with a high epoxy value of 6.28%.In the third part, a new type of catalyst was synthesized by modifying silica gel with ionic liquid and active W species. The layer number of ionic liquid was increased to improve the amount of the active species. In order to optimize the reaction condition, L9(33) orthogonal experiment was carried out. The separation of final products and recovery of catalysts were easier when the catalyst was supported on the silica gel. However, the catalytic activity of the catalysts decreased and the epoxy value of the product required improving.更多还原