Catalytic performance of [C_(16)H_(33)N(CH_3)_3]_3[PO_4(WO_3)_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]3[PO4(WO3)4] as a reaction controlled phase transfer catalyst was investigated. The results indicated that p H of the aqueous phase was the most important factor and the proper p H 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.