Heterogeneous catalysts for the production of new lubricants with unique properties

The heterogeneously catalyzed nucleophilic addition of carboxylic acid to the epoxide center in the epoxidized methyl-cis-9-octadecenoate (eOME) was attempted and the lubricant properties of the resulted hydroxy esters are reported. It is demonstrated that solid acid catalysts like Nafion, Nafion–silica composites (SAC), Amberlyst 15, Amberlite IR 120, zeolite H-Y and montmorillonite were promising and selective catalysts for hydroxy ester formation at reaction temperature 30 °C. The lubricant properties of various hydroxy esters were evaluated by rotary bomb testing, which indicates higher oxidation stability of the hydroxyl di esters than the starting material, methyl oleate. The viscosity index calculation shows that the viscosities of the hydroxy esters are significantly influenced by the size of the carbon chain and nature of the carboxylic acid.

Graphical abstractThe heterogeneously catalyzed nucleophilic addition of carboxylic acids to epodized methyl-cis-9-octadecenoate (eOME) was investigated. Solid acid catalysts like Nafion, Nafion/silica composites, Amberlyst, Amberlite, zeolite Y and montmorillonite were used. Taking into consideration catalyst stability and cost-efficiency, the best results were obtained with Amberlyst 15. Lubricant properties of the resulting fluids were tested. The carbon chain length of the carboxylic acid used influenced the oils viscosity.Figure optionsDownload full-size imageDownload as PowerPoint slide