Synthesis and characterization of N-acyl alkanolamide surfactant from fatty acids and alcohol amines using sodium methoxide catalyst

Abstract

Surfactant is a substance added to the liquid that improves the spread's properties by weakening the liquid's surface voltage. Surfactants have a molecular structure consisting of hydrophilic groups and hydrophobic groups. Surfactant needs in Indonesia continue to increase along with the development of industries in Indonesia. This study will be synthesized by the N-acyl surfactant alkanolamide using one type of alcohol amine, namely diethanolamine, through a reaction of amidation between fatty acids and using organic solvents tert-amyl alcohol. The catalyst used is a chemical catalyst, namely sodium methoxide. Furthermore, the purpose of this research is to determine the effect of reaction variables and determine the characteristics of the N-acyl alkanolamide surfactant in the form of acidic numbers and spreading numbers. This study showed for lauric acid, palmitate acid, and the best stearate acid at 90 oC reaction temperatures and 2-hour reaction times, while the best succinic acid at 100 oC and a reaction time of 2 hours. The relationship between reaction rate and time is directly proportional; the longer the reaction time, the higher the rate. The conversion relationship with reaction time is directly proportional, where conversion will increase with the increase in reaction time. However, this does not happen to all fatty acids. Due to the increase in reaction time, it will not provide significant results on surfactant products. The relation between the reaction temperature and the conversion acquisition at the time obtained decreased along with the increase in reaction temperatures. The acid numbers in the best conditions in a row are 40.67 for N-palmitoyl diethanolamine, 47.41 for N-lauroyl diethanolamine, 63.11 for N-succinyl diethanolamine, and 22.44 for N-stearoyl diethanolamine. The saponification number in the best conditions in a row is 36.47 for N-palmitoyl diethanolamine, 23.84 for N-lauroyl diethanolamine, 57.50 for N-succinoyl diethanolamine, and 7.01 for N-stearoyl diethanolamine.