[C16H33N(CH3)3]3[PO4(WO3)4]催化脂肪酸甲酯环氧化性能

在无酸、无溶剂条件下,以C₁₆H₃₃N(CH₃)₃]₃PO₄(WO₃)₄]为反应控制相转移催化剂,研究各因素对脂肪酸甲酯(FAME)环氧化反应的影响。结果表明,水相pH对环氧化反应的影响最大,反应适宜pH为4;适宜反应条件为过氧化氢与脂肪酸甲酯中双键摩尔比为1.05:1,反应温度50～60℃,反应时间5 h。在此反应条件下催化剂循环5次不失活,产品环氧值大于4.0%,碘值小于5 g I·(100 g)^-1。并通过元素分析与红外光谱,研究了催化剂在反应过程中的变化,认为磷钨杂多阴离子的分解是导致催化剂失活的关键原因。

Catalytic performance of [C16H33N(CH3)3]3[PO4(WO3)4] in fatty acid methyl ester epoxidation

The influence of reaction conditions on epoxidation of unsaturated fatty acid methyl ester (FAME) under acid and solvent free conditions with C₁₆H₃₃N(CH₃)₃]₃PO₄(WO₃)₄] as a reaction controlled phase transfer catalyst was investigated. The results indicated that pH of the aqueous phase was the most important factor and the proper pH value of solution was 4. With molar ratio of hydrogen peroxide to double bond in FAME is 1.05:1, reaction at 50—60℃ for 5 h, the catalyst could be recycled 5 times without deactivation, and epoxy value of the product was more than 4.0%, while iodine value was less than 5 g I·(100 g)^-1. Change of catalyst during the epoxidation process was investigated with IR spectroscopy and elemental analysis, and the result indicated that decomposition of heteropolyphosphatotungstate anion was the key reason for catalyst deactivation.