Development of polyols analogous to neopentyl glycol and trimethylolpropane for the production of oleic acid-based biolubricants

Vegetable oils and animal fats have been known and used as lubricants and fuels since ancient times. However, the chain structure of the triacylglycerols (TAGs) generate limitations that discourage the use of these raw materials as lubricants. As an alternative to improve the physicochemical and thermo-oxidative characteristics of natural oils, the use of polyols without the beta-hydrogens in the triacylglycerols structure is an efficient solution for the production of biolubricants. In this context, a series of polyols, analogous to trimethylolpropane (TMP) and neopentyl glycol (NPG) was synthesised and applied in the synthesis of polyol esters based on oleic acid. These esters were prepared by homogeneous catalysis using p-toluenesulfonic acid (p-TSA) and are intended for use as biolubricants. The synthesised polyols were characterized by one and two-dimensional NMR. The derived polyol esters were purified and had their structure confirmed by H-1 and (CNMR)-C-13, infrared spectroscopy, and mass spectrometry. The polyol esters showed high viscosity index (189 - 222), thermo-oxidative stability (T onset between 258 and 285 degrees C), and low melting points (between -19.4 and -47.6 degrees C). Furthermore, polyol esters showed reduced friction coefficients (0.021 - 0.041) and scar wear diameter on the metallic surface (0.274 - 0.448 mm). In addition to the satisfactory results of thermal stability and lubricity, which suggest the potential of these molecules as lubricants, all molecules were considered environmentally safe when evaluated through the Zebrafish toxicity model.