جستجوی مقالات مرتبط با کلیدواژه « Polyol Esters » در نشریات گروه « شیمی »

Esterification reactions of some polyols and diols were investigated in the presence of SnO2 and nano-SnO2 and the results were compared with the catalyst-free conditions. High conversions were obtained for most of the reactions in the presence of SnO2 and nano-SnO2 which shows the high catalytic activity of SnO2 and nano-SnO2 for the esterification reaction. Low cost of the catalysts compared to alkyl tins, high safety compared to protic acids such as sulfuric acid and high chemical and thermal stability of the catalysts make the reactions interesting for the large-scale production of various polyol esters. Due to the important role of the polyol esters in various industries especially in the lubricant industry, the introduced approach can be interesting.

Esterification and transesterification reactions usually carry out in hydrocarbon solvents, such as toluene. Homogeneous acid catalysts such as, sulfuric acid, methane sulfonic acid, and p-toluene sulfonic acid are the most conventional catalysts for this purpose. Application of these catalysts causes some difficulties such as corrosion, and environment probleA most effective and less energy demanding method of producing fatty esters, polyol esters , by esterifying fatty acids, with a pentaerythritol and trimethylolpropan alcohols in the presence of an acid Catalyst at elevated temperature wherein an azeotroping agent , particularly toluene, is used to facilitate continuous removal of water by distillation, formed as a by-product during the esterification reaction.The esterification reaction is completed within 5 hours, pentaerythritol and trimethylolpropan esters was produced .ms