| Summary: | The optimizations on the synthesis of two surfactants namely lauroyl-diethanolamide and lauroyl-N-methyl glucamide, which can be used in formulating cosmetics and pharmacy supplies, are studied. The fraction of palm kernel oil namely lauric acid was amidificationed with diethanolamide and N-methyl glucamine to form lauroyl-diethanoamide and lauroil-N-methyl glucamide, respectively. Study was carried out by using two immobilized enzymes namely lipase from Rhizomucor miehei (Lipozyme TL IM®) and lipase from Candida antarctica (Novozyme 435®), and a numbers of solvent namely n-hexane, tert-butanol, tert-amylalcohol and isopropanol. Study consists of three stages of work, i.e. preliminary stage, optimization stage, and development process stage. In the preliminary stage, the reaction variables observed were reaction time, enzyme’s type and concentration, solvent’s type and ratio, molar ratio of substrate (amine/lauric acid), and temperature. In the optimization stage, regression model and the interactions of Novozym concentration, molar ratio of substrate, and temperature were optimized to obtain response of lauric acid conversion and percentage of maximum yield. Optimization was carried out by utilizing the Central Composite Design (CCD) and Response Surface Methodology (RSM). In the development process stage, the frequent addition of amine was observed, the condition without solvent, enzyme recovery and synthesis scale up in multistage bioreactor were implemented. The results of preliminary stage show that in the synthesis of lauroyl-dietanolamide, the Novozym with concentration of 10% (b/b AL), n-hexane with solvent ratio 2:1 (v/b AL), molar substrate ratio (DEA/AL) 3:1, temperature of 50 oC and reaction time of 24 hours, give the best performance. The expected optimum condition in the synthesis of lauroyl-diethanolamide was at molar ratio DEA:AL 3:1; Novozym concentration of 10% at temperature of 50-55 oC, and in the synthesis of lauroyl-N-methyl glucamide was at molar ratio MGL:AL 1:1; Novozym concentration of 8% at temperature of 50-55 oC. The reactions at the optimum condition produce the percentage of lauric acid convertion of 73.05% and yield of 77.85% for the synthesis of lauroyl-diethanolamide and the convertion of lauric acid of 64.5% and yield of 97.59% for the synthesis of lauroyl-N-methyl glucamide. The best addition of amine was done by 2-3 stages while the enzyme usage was up to 4 times of repetition, and it was indicated by the high conversion performance of lauric acid. The synthesis scale up using multi-stage bioreactor show that at motor rotation of 150 rpm (Rea 1618), stirrer type B (45o paddle) gives higher percentage of lauryl acid conversion, while at motor rotation of 250 rpm (Rea 2697), in overall stirrer A and B gives similar result of lauryl acid conversion. For the purpose of verifying of amidification reaction, spectroscopy FT-IR and 1H-NMR were carried out for structure testing while HPLC analysis was done for the magnitude of yield percentage. Moreover, the HLB measurement and the other analyses of physical property were done by titration method. The expectation output of the study in this research is producing the economic and natural alkanolamide surfactant because it is made of renewable raw materials and produced under ecologically acceptable process. 068103007
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