Speaker
Description
Study of the using of renewable sources of raw materials is widespread and popularized. It is replacement for raw materials of petrochemical origin. It is due to strengthening of ecological standards. The presence of double bonds in vegetable oils and their derivatives gives a possibility to functionalize them into value-added products. The Wacker type process of vegetable oils and them derivatives is interesting for studying. The reaction leads to produce ketocarboxylates, as well as the further conversion of these groups to carboxylic. There are might use hydrogen peroxide and organically peracids as an oxidant [1].
The Wacker process or the Hoechst–Wacker process originally referred to the oxidation of ethylene to acetaldehyde by oxygen in water in the presence of a palladium tetrachloride catalyst. This chemical reaction was the first organometallic and organopalladium reaction applied in industrial scale [2]. However, the catalyst system and reaction conditions are also applied to oxidations and oxidative cleavage of renewables [3, 4, 5]. The work focuses on choosing conditions for the oxidation of unsaturated fatty acid derivatives and vegetable oils and the identification of oxidation products.
Oleic acid was chosen for beginning the research. Сatalytic oxidation of oleic acide with air in the presence of palladium (II) chloride and copper (II) chloride was carried out. The synthesis is carried out in a cylindrical three-necked reactor with stirring. Air was bubbled through the reaction mass (feed rate – 0,5 liter/min).
Fourier transform infrared spectroscopy (FTIR) was used to identify of presence of ketones groups in the resulting product. The spectrum of product are containing of ketones groups and the spectrum of raw oleic acid were compared. The presence of ketones group is reflected in the increased intensity of the band at 1620 см-1. The result shows that the conditions of the industrial Waker type process might be applied to the production of fatty ketones without creating of an excessive pressure in the system when the oxidant is the air's oxygen. It is mean the selective obtain of fatty ketones by this method allow to produce valuable organic synthesis products (dicarboxylic acids, fatty alcohols, plasticizers, polyesters, biodegradable fibers).
References
[1] A. Köckritz, A. Martin: Oxidation of unsaturated fatty acid derivatives and vegetable oils. Eur. J. Lipid Sci. Technol. 2008, 110, 812–824.
[2] B. Cornils, W. A. Herrmann, R. Schlögl, C.-H. Wong (Eds.): Catalysis from A to Z – A Concise Encyclopedia. Wiley-VCH, Weinheim (Germany) 2000.
[3] S. Warwel, M. Rüsch gen. Klaas: Oxidative cleavage of unsaturated fatty acids without ozone. Lipid Technol. 1997, 9, 130–132.
[4] I. Hermans, K. Janssen, B. Moens, A. Philippaerts, B. Van Berlo, J. Peeters, P. A. Jacobs, B. F. Sels: Solvent- and metalfree ketonization of fatty acid methyl esters and triacylglycerols with nitrous oxide. Adv Synth Catal. 2007, 349, 1604– 1608.
[5] G. Knothe: Synthesis and characterization of long-chain 1,2-dioxo compounds. Chem Phys Lipids. 2002, 115, 85–91.
