Petroleum Chemistry, Vol.60, No.11, 1309-1316, 2020
Synthesis of Fatty Alcohol based Sterically Hindered Esters as Potential Antioxidants for Bioadditives
Four hindered phenolic esters were prepared by esterification between 3-(3,5-Di-tert-butyl-hydroxyphenyl)propionic acid and fatty alcohols. The synthesized esters were characterised by NMR, IR and ESI-MS and analysed for their antioxidant properties and thermal stability. Differential scanning calorimetry (DSC) and Rancimat studies were conducted to explore the effect of synthesized compounds on oxidation stability of base oil. The results from both the studies were correlated well. Thermogravimetric analysis indicates that all the esters have significantly high thermal stability. Among all the prepared compounds myristyl alcohol ester showed better antioxidant properties whereas, stearyl alcohol ester exhibited higher thermal stability. The synthesized antioxidants can be potential bio additives for lubricant formulations.
Keywords:differential scanning calorimetry;thermal stability;oxidation induction time;rancimat;surface-volume ratio