Submitted to: Journal of Agriculture and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/30/2005
Publication Date: 10/29/2005
Citation: Doll, K.M., Erhan, S.Z. 2005. Synthesis of carbonated fatty methyl esters using supercritical carbon dioxide. Journal of Agricultural and Food Chemistry. 53(24):9608-9614. Interpretive Summary: We have synthesized two cyclic carbonates from readily available vegetable oil based materials. Methyl oleate and methyl linoleate were first treated with hydrogen peroxide, then the product from that reaction was reacted with supercritical carbon dioxide. This is a different route than was used previously in the literature, and it is advantageous because it uses carbon dioxide directly. We also synthesized a cyclic carbonate from a commmercially available fatty material. We have studied the thermal stability of the carbonates and found that they are more stable than the original fatty materials. There are possible uses for these materials as building blocks for surfactants and polymers, or directly as lubricant additives. This research benefits the vegetable oil industry by helping to open markets for vegetable oil derived products in te polymer, surfactant, and lubricant industries.
Technical Abstract: The two step syntheses of the cyclic carbonates: carbonated methyl oleate (CMO) and carbonated methyl linoleate (CML) are reported. First, synthesis of the epoxide through well precedented chemical reaction of unsaturated fatty methyl esters with hydrogen peroxide and formic acid is performed. Next, we use a carbonation reaction with a simple tetrabutylammonium bromide catalyst allowing the direct incorporation of carbon dioxide into the olechemical. The use of the higher density of supercritical carbon dioxide overcomes its low reactivity and allows the carbonation reaction to be performed overnight. Our synthesis also avoids the use of the environmentally unfriendly phosgene. The carbonated products are characterized by IR, 1H NMR, and 13C NMR spectroscopy, and studied by thermogravometric analysis (TGA). Also reported is the synthesis of a similar cyclic carbonate from the commercially available 2-ethylhexyl epoxy soyate. These carbonates show properties which may make them useful as petrochemical replacements, or as bio-based industrial product building blocks.