Polymeric Acidic Ionic Liquid-Functionalized SBA-15 as a Solid Catalyst for Production of Low-Calorie Structured Lipids

The aim of this study is to develop a clean and environmentally friendly process for production of low-calorie structured lipids in accordance with the requirement of cleaner production and sustainable developments. To achieve this, polymeric acidic ionic liquid (IL)-functionalized SBA-15 catalysts were prepared by surface grafting copolymerization of IL 1-propylsulfonate-3-vinylimidazolium hydrogen sulfate onto the SBA-15 support using azobisisobutyronitrile (AIBN) as an initiator. The as-prepared solid catalysts were fully characterized using several techniques. Results demonstrated that the polymeric acidic IL was successfully tethered on the SBA-15 silica, and the mesoporous structure of the SBA-15 support remained intact after the grafting copolymerization. The solid catalyst showed high activities in the soybean oil acidolysis with capric and caprylic acids. The acidolysis products were analyzed by a gas chromatographic method, and the incorporation of medium-chain fatty acids into soybean triacylglycerols was 53.4% over this solid catalyst. Furthermore, the solid catalyst could be recycled several times without appreciable loss of its activity.