Synthesis of Polyethylene Glycol Esters from Oleic, Stearic, and Palmitic Acids as a Pour Point Depressant (PPD)

Polyethylene glycol (PEG) ester is a non ionic surfactant compound that could use a pour point depressant (PPD) for crude oil. Synthesis of PEG-ester with reflux and mono wave-50 methods through esterification fatty acid such as oleic acid, stearic acid, and palmitic acid with adding p-toluene sulfonic acid (p-TSA) as a catalyst. The product of esterification could be a mixture of monoester and diester. Synthesized PEG ester by reflux method resulted in higher yield than by mono wave-50 method. IR spectra analysis of PEG400-oleate, PEG400-stearate, and PEG400-palmitate show the presence of an absorption band at a wavenumber of around 1100 cm-1 that indicates the stretching vibration of the C-O ester. (LC-MS/MS) analysis that shows the molecular weight of PEG400-oleate was 845.6154 g/mol and, PEG400-stearate was 785.5952 g/mol. Mean, while PEG400-palmitate produced three ester compounds with different molecular weights: 741.5669 g/mol, 685.5057 g/mol, and 734.5208 g/mol. The pour point measurement results show that the PEG-fatty acid product in the range of 0.1% to 1% has not been able to reduce the pour point of the crude oil sample. Keywords: Esterification, FTIR, LC-MS/MS, Surfactant