| 摘要註: |
植物油脂是由脂肪酸和甘油化合成的天然化合物，為一種可再生之特殊化學品。不飽和植物油脂經過環氧化水解合成羥基脂肪酸，可具有氧化穩定性與高流動性之優點。可供為製造生質潤滑油的基礎油，綠色科學強調生物可分解性、環境友善性與低毒性述求。傳統環氧化反應採用過氧羧酸(主要是過氧甲酸或過氧乙酸)做為氧化劑氧化劑，生產過程中生成有機過氧酸極不穩定，造成易爆炸、產品穩定性差、產品選擇率低等問題，同時腐蝕設備產生大量有機過氧酸廢水，引起環境汙染。近年來越來越多科學家尋找更環境友善型化劑，本研究Ti分子篩催化不飽和脂肪酸之環氧化反應，探討觸媒設計要因與反應影響因子，期能突破目前催化劑性能。吾人比較各種微/介孔Ti分子篩針對植物油環氧化反應研究，包括規則性介孔材料結晶化(PCM)和介孔結構TS-1晶種自組裝等，其一是規則性介孔材料結晶化(PCM)，從起始的Ti-MCM-41規則型結構逐漸轉換成TS-1結晶構造，利用XRD繞射圖可追蹤結晶化的程度，結晶化六小時Ti-M-Z-6h樣品催化不飽和脂肪酸一個雙鍵的油酸甲酯獲得較高的轉換率66 %選擇率94 %，可能係因Ti-M-Z-6h有較高的擴散係數，另外有四配位，繼之隨著結晶化時間增長，TS-1結晶度增強，但環氧化轉化率隨之下降。兩個雙鍵的亞油酸甲酯，同之。其二為TS-1晶種自組裝，先製備TS-1晶種奈米顆粒前驅液，在界面活性組裝組成介孔結構，樣品平均轉化率約40 %和選擇率約90 %。 Vegetable oil can be considered to be formed by condensation of a glycerol molecular with three mole of fatty acid (FA), resulting in the formation of a triglyceride molecular and three water molecular. In recent decade, epoxidation of plant oil is a commercially important reaction because the epoxides are obtained from these renewable raw material and from the methyl oleate, their transesterification product, have applications as plasticizers and stabilizer in chloride containing resins, as components in the thermosetting resin. Theses epoxides (the epoxidized oleates) can be used as intermediate in the production of a variety of derivative, monoalcohols, doils, alkoxyalcohol, hydroxynitriles, hydroxyester, mercaptoalcohol and aminoalcohol could be product via epoxide ring-opening reaction, which are better cold flow properties and oxidative stability. The explotation of fats from vegetable source implies many advantages: eco-compatible, renewable, biodegradable, and non-noxious compound toward greenhouse effect. Traditionally, epoxy vegetable oils are obtained by peracid oxidant in situ in presence of carboxylic acid react with hydrogen peroxide. However, there are several drawbacks must be improved in the peracid process, including:(1)the low selectivity due to the acid catalysed oxirane opening; (2) the separation of acidic byproducts , whose presence may be detrimental for further application, is not easy; (3) the corrosion problems and serious pollution that are due to peracid used. Many studies about the novel catalysts for the epoxidation of vegetable oil have been reported, such as lipase candida (Novozyme 435), MTO, alumina, Ti-MCM-41, Ti/SiO2, tungsten, and ion exchange resins. In this work compare Ti molecular sieve. For the epoxidation oleic acid methyl ester, different kind of partial crystallization of performed mesoporous material(PCM) and surfactant-mediated assembly of zeolite seeds into mesoporous structure are prepared. Ti-MCM-41 with Ti/Si of 0.02 was transformed into x-ray amorphous PCM starting at 6 h with tetrahedron titanium remained in the structure. With increasing crystallization time, the pore size of PCM after initial reduction increased gradually and its pore volume decreased. The FAME conversion increased from 40% for Ti-MCM-41 to reach a maximum of 66% at 94% epoxide selectivity for PCM at crystallization time of 6 h. There are almost same conversion and selectivity at the samples (TS-20,TS-20-140, and TS-80-100) in surfactant-mediated assembly of zeolite seeds into mesoporous structure. |