Statistical optimization of the synthesis of plant-derived fatty acid esters of TMP over homogeneous organometallic tin catalyst

A class of very important industrial-grade biolubricants was synthesized from plant-derived fatty acids (oleic and isostearic acid) by direct esterification of trimethylolpropane according to novel effective and high selective method using Sn bis(2-ethylhexanoate) as catalyst. Model transesterification reactions were performed with oleic and isostearic acids to optimize the reaction conditions to obtain maximum content of TMP triesters. Used specific homogeneous Sn catalyst allows to obtain TMP esters with very high content of triesters, above of 94 wt% without deep vacuum purifying distillation. Both TMP esters were evaluated for their physicochemical and tribological properties using ASTM standards. Both TMP esters exhibited high viscosity indexes and excellent low temperature properties.