Epoxidation Of Methyl Oleate Research Articles

Selective epoxidation of unsaturated fatty esters over peroxophosphotungstic catalysts (POW) under solvent free conditions: Study of the POW catalyst's mechanism

Methyl oleate epoxidation with a peroxophosphotungstate (POW) catalyst was performed under solvent free conditions. After underlying a synergistic effect of hydrogen peroxide and the dioxygen flow to obtain a total epoxide yield, new investigations were realized to understand this effect. The POW catalyst mechanism was studied using labeled oxygen flow and radical traps. We concluded that the reaction occurs in two parallel ways, a major one thanks to a concerted mechanism and a minor radicalar one leading to the formation of methyl stearate alcohol and diol intermediates. Oxygen flow is only necessary to perform the radicalar way.

Epoxidation of Methyl Oleate Using Heterogeneous Catalyst

In this work, we studied the catalytic activity of commercial alumina, and laboratory-synthesized alumina doped with Lewis acid metals, in the epoxidation of methyl oleate with aqueous hydrogen peroxide. It was observed that the reaction yields increased when the amount of catalyst, the quantity of hydrogen peroxide, the concentration of the hydrogen peroxide solution, or the surface area of the catalyst was increased. Reaction yields decreased when the surface acidity of the alumina was modified by doping with Lewis acid metals.

Solvent-free selective epoxidation of fatty esters over a tungsten-based catalyst

A solvent-free, rather complete and selective cis epoxidation of methyl oleate (MO) using a tungsten-containing catalyst called “Tetrakis”. High epoxide yields have been obtained by adjusting the reaction parameters (reaction time, temperature, gas phase, oxidant molar ratio and concentration). The highest selectivities are the result of a synergetic effect of hydrogen peroxide and air (or oxygen) used as oxidizing agents that decreases the MO dimerization and then favour the complete conversion of MO into its epoxide.

Epoxidation of methyl oleate with molecular oxygen in the presence of aldehydes

AbstractThe epoxidation of methyl oleate with molecular oxygen in the presence of aldehydes was investigated and optimized. Epoxide yields up to 99% were observed in organic solvents. The preponderant radical reaction was started by a single organic radical chain initiator, without using a metal catalyst. The radical character of the reaction was revealed by the concurrent occurrence of trans and cis epoxides and by the prevention of epoxide formation through a radical scavenger. Both branched aldehydes and the linear aldehyde n‐hexanal were well suited in organic solvents. The linear n‐hexanal enabled also a superior epoxide yield of 78% in the green solvent water. The oxidation of high‐oleic sunflower oil under the same conditions with n‐hexanal yielded 39% epoxide groups.

A polarographic investigation of the kinetics of epoxidation of unsaturated fatty acid esters

SummaryA polarographic technique which uses a nonaqueous electrolytic solution consisting of 0.25M ammonium acetate in glacial acetic acid is a suitable medium for the investigation of the kinetics of fatty acid ester epoxidations. From the polarographic data the specific reaction rate constants for the perlauric acid epoxidation of vinyl laurate, methyl oleate, and vinyl oleate in benzene at 25°C. were found to be 12, 232, and 270 × 10−3 l./mole−1 min−1. The Arrhenius equation for the epoxidations of methyl oleate and vinyl oleate by perlauric acid can be expressed as

Epoxidation of methyl oleate with hydrogen peroxide

SummarySimple addition of hydrogen peroxide to a 10 molar excess of glacial acetic acid in the presence of sulfuric acid catalyst gave about 90% conversion to peracetic acid in the peracid preforming step.Improved hydrogen peroxide efficiency in the epoxidation step was obtained by using a 0.9:1 molar ratio of preformed peracetic acid to methyl oleate. Under these conditions most of the peracetic acid was used in forming the epoxide.Stainless Steels 304, 316, 321, 329, and 430 are satisfactory as materials of construction from the standpoint of both corrosion resistance and effect on the reaction.