Vol. 12 | No. 2 |733 - 740| April - June | 2019 ISSN: 0974-1496 | e-ISSN: 0976-0083 | CODEN: RJCABP http://www.rasayanjournal.com http://www.rasayanjournal.co.in Rasayan J. Chem., 12(2), 733-740(2019) http://dx.doi.org/10.31788/RJC.2019.1225116 OPTIMIZATION OF ALKYL-DIETHANOLAMIDE SYNTHESIS FROM FATTY ACID METHYL ESTER OF COCONUT OIL USING BOX-BEHNKEN DESIGN Z. Masyithah 1,* , S.R. Yudhika 1 , L. Simanjuntak 1 and A. Ginting 2 1 Department of Chemical Engineering, Faculty of Engineering, Universitas Sumatera Utara, Jalan Almamater, Medan 20155, Indonesia 2 Department of Mechanical Engineering, Faculty of Engineering, Universitas Sumatera Utara, Jalan Almamater, Medan 20155, Indonesia *E-mail :zuhrina@yahoo.com ABSTRACT Alkyl-diethanolamide from renewable materials has become much of current interest for the surfactants. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects on stirring speed, catalyst concentration and temperature on percentage acid conversion to alkyl-diethanolamide. Predictive models for amidation of fatty acid methyl esters (FAME) from coconut oil shows that the model prepared is adequate and reproducible to represent the data obtained (R 2 = 95.74%). The fatty acid conversion significantly increased with stirring speed and reaction temperature, and increasing catalyst concentration did not significantly increase the yield of alkyl-diethanolamide. The optimal reaction conditions were predicted at the stirring speed of 350 rpm, catalyst concentration of 4% (w/wFAME) and temperature of 70-75 o C. Under optimized condition, the conversion of FAME was up to 97.57% in 3 hr. Keywords: Coconut Oil, Fatty Acid Methyl Ester, Diethanolamine, Response Surface Methodology, Alkyl Diethanolamide © RASĀYAN. All rights reserved INTRODUCTION Surfactants are surface active agents, which can reduce the surface tension by forming films between the two media, such that the interaction is stable, and results in reduced surface tension. 1 Surface tension is an important characteristic of fluids. Simply put, this is a force acting on the surface of a liquid, which tends to minimize the surface area that affects physical properties, such as the ability to wet fluids. Surface tension tends to attract molecules on the interphase inward, thereby reducing the interaction between the two phases. 2 In the dairy industry, for example, milk surface tension is an important characteristic because it has an impact on the formation of emulsions. 3-4 Alkanolamide surfactant is a product of condensation reaction between alkanolamine with fatty acids, methyl esters or triglycerides. 5-6 Alkanolamide is a compound that shows low reactivity, high thermal stability, very chemically stable and not easily degraded in alkaline media. 7-8 For this reason, alkanolamide is widely applied as an emulsifier and has a broad spectrum of uses such as shampoo, detergent, cosmetics, lubricants, and other home products. 9-10 For this reason, economic materials and methods, and using environmentally friendly reaction conditions have been the hallmarks of studies of these products in recent years. 11 One of the raw materials for making alkanolamides is economical and abundantly comes from coconut plants. Coconut (Cocosnucifera Linn.) Belongs to the Arecaceae family, cultivated mainly in the tropics with high humidity, regular rainfall, and sandy soil. Approximately 90% of the total composition of coconut oil consists of Saturated Fatty Acid (SFA). 12-13 The main fatty acids (Fatty Acid, FA) found in