The Extraction, Purification Of Litsea Cubeba Kernel Oil And Its Application In The Synthesis Of Surfactant

Litsea cubeba(Lour.)Pers, a kind of endemic spice plant which is cultivated in Hunan, Sichuan, Fujian, Guangdong, Guangxi and other provinces of China. Large amounts of solid residues mainly are Litsea cubeba kernel would be produced after having extracted the Litsea cubeba essential oil. The solid residues were used as material to extract Litsea cubeba kernel oil then the oil were used to prepare the high quality of fatty acid and synthesis the non-ionic surfactant of 1:2 type of lauric acid diethanolamide in this dissertation.The main results of the present research can be summarized as following aspects:1、The extracting method and optimal process of kernel oil from Litsea cubeba residues were obtained.The solvent refluxing extraction method was used to extract the kernel oil from Litsea cubeba residues. The optimal technology conditions were obtained as followed: extractant was petroleum ether (60-90℃), particle-size of material less than 100 mesh, extracting temperature 80 ℃, material-solvent ratio 1:14(g/mL) and extracting time 2 h. The maximum yield of kernel oil was reached at 26.69% under the above conditions.2、The chemical compositions of fatty acids of Litsea cubeba kernel oil were obtained.The chemical compositions of kernel oil fatty acids were determined by GC-MS technology. The result showed that the content of capric acid, lauric acid, palmitic acid, linoleic acid and oleic acid were relatively high. There are 40.54% of medium-chain fatty acid that the carbon is from 10-14, and mainly are lauric acid and capric acid. The major components of unsaturated fatty acids are linoleic acid and oleic acid.3、The process of Litsea cubeba fatty acids preparation and the high purity of lauric acid seperation from kernel oil were obtained, and the process optimized.(1) The Litsea cubeba kernel oil were effectively refined and the rate of impurity substance removal was reached at 95% by using sulfuric acid refining process.(2) The yield of litsea cubeba fatty acid was reached at 94% by using the process of saponification and acidification hydrolysis.(3) The main component of capric and lauric acid were separated effectively and the content of lauric acid was reached at 83.66% in the purified product by using the technology of distillation.(4) The solvent crystallization method were used to prepare the high purity of lauric acid from Litsea cubeba kernel oil. The purity of lauric acid was up to 98% under the optimized condition of solid-liquid ratio 1:2:10(g:mL:mL), crystallization time 4 h and temperature-17.5℃.4、A kind of analysis method by high performance liquid chromatography (HPLC) was established for quantifying 1:2 type of lauric acid diethanolamide.The optimal analysis conditions by HPLC was obtained as follows:Shimadzu High Performance Liquid Chromatography Equipment, SPD-20A UV detector, ODS-C18 column (250mm×4.6mm,5μm), mobile phase:90% methanol aqueous solution (V/V), flow rate was 1.0 mL/min, detection wavelength 203 nm, column temperature 37 ℃, injection volumn 10 μL.The lauric acid diethanolamide were well isolated under the optimal analysis condition mentioned above. The calibration curve was linerar in the range of the injection volumn of 0.5-12.5μg. The RSD of accuracy of the analysis. method was 0.5437%. The recovery rate of lauric acid diethanolamide was 98.97-101.36%.5、The synthesis technology of 1:2 type of lauric acid diethanolamide was obtained.The lauric acid diethanolamide was synthesized by two step synthetic process catalyzed by sodium methoxide, the optimal conditions were obtained and as followed:(1) First step:reaction time 4 h, reaction temperature 140℃, material-liquid ratio 1:1.2(mol:mol),(2) Second step:reaction time 2 h, reaction temperature 80 ℃, addition of diethanol amine 0.6:1 (mol:mol), catalyst 0.75%(wt%).The content of 1:2 type of lauric acid diethanolamide was reached at 76% under the above conditions.6、Three kinds of the lauric acid diethanolamide products were produced and the performance parameter such as active matter content, amine value, pH value and frothing capacity tested by GB/T 15046-94 were obtained. The major qualification between the products and coconut fatty acid diethanolamide were contrasted.(1) The qualification such as amine value and active matter content of the product synthesized by lauric acid of distillation was up to the standard of conforming article.(2) The qualification of the product produced by lauric acid of solvent crystallization was up to the standard of premium grad.(3) Each product had high performance of frothing capacity and the performance was superior to coconut fatty acid diethanolamide. The frothing capacity is directly proportional to the content of lauric acid diethanolamide.