Authors discussed the mechanism of oil separation from the tissue of rice bran by comparing the expression and the solvent extraction method, from differences in their properties of extracted and remained oils. Assuming here that the main components of rice bran oil are free fatty acids, glycerides and wax esters, the wax esters are firstly separated and the free fatty acids follow in the expression method. Whereas, there are reverse selective tendency in the solvent extraction. However, industrial data shows that the differences and elevation in the acid value of crude oil by both methods are small. It is generally said that the extracted crude rice bran oil is more difficult for refining than the expressed oil, but, authors found the reverse case when extraction temperature was controlled and extraction was processed by separating steps.
The upper limit of acid value of rice bran oil, after naturally stored as rice bran and as the oil for 1 to 2 years, has been discussed statistically. The average properties of rice bran sample were 12.6% in moisture and 18.9% in oil content. From the above result, natural hydrolysis will not be suitable to prepare crude fatty acid for distillation because of low degree in the hydrolysis. There was about 2% decrease of fatty material in the rice bran when naturally hydrolysed. The higher acid value of oil in the rice bran showed a decreased remaining oil content in the extracted flakes, indicating the influence of natural hydrolysis. Also, the acid value of remained oil in the extracted flakes was lower than that of raw rice bran. From these results, it is presumable that the fatty acid is solvent-extracted easier than the glycerides and esters.
In as much as the oryzanol can be efficiently recovered from rice bran oil, two processes using an anion exchange resin were investigated. In the first process, oryzanol and free fatty acid adsorbed by resin were simultaneously desorbed with the mixture of benzene, methanol and hydrochloric acid (or acetic acid gracial, boric acid etc.) solution from which oryzanol was recovered with good result. In the second, oryzanol was separately adsorbed by the resin esterifying the free fatty acid and then oryzanol was desorbed and recovered with the same mixed solution. Both processes are recommended as practical.
When rice bran oil dissolved in some organic solvents is passed through a bed consisting of strongly basic anion exchange resin treated in nonaqueous circumstances, the most parts of free fatty acids and oryzanol contained in the oil can be adsorbed by the resin. In order to obtain a selective extraction method of the both components, MeOH-H3BO3 system and MeOH-HCl system, as the nonaqueous solvent, were tested. Satisfactory results were obtained with the former system in which most part of oryzanol was desorbed but almost parts of fatty acids were not desorbed.
Methyl linolate has been known to dimerize by thermal polymerization. The authors polymerized four different isomers of methyl linolate in inert gas atomosphere by thermal process in the present work. From an investigation of these polymers thus prepared it was confirmed that isomerization of double bond resulted in the formation of conjugated trans-trans and nonconjugated trans isomers and then these two isomers underwent Diels-Alder's type addition. From a study on the structure of the dimer by means of ozonization, the same result of the Kappelmier's postulate was obtained.
To analyze the miscella stripping process of solvent extraction of soybeans in the battery system, the specific interfacial tensions of hexane miscella to water and their boiling points in various concentration were investigated. It was found necessary to concentrate hexane miscella as possible at the beginning of stripping for preventing emulsification. It was possible to separate hydrated soybean lecithin of high purity by adding appropreated-water into the stripper at the end of stripping process and also by charging water into settling tank prior to send finished oil. Then, the optimum condition was investigated to break down lecithin miscella and to bleach it by using hydrogen peroxide as bleaching agent and ammonium hydroxide as assistant. Further experiments have been made to survey the conditions for spray drying of aged materials. A powdered soybean lecithin of 92 to 96% purity could be prepared without using any solvent.
Chromatographic separation of acetic acid esters of higher fatty alcohols was studied for purpose of application of gas chromatography to analysis. As a result resolution effects of several partitioning agents, such as α-polyester which had been prepared from diethylene glycol and dibasic acid of low molecular weight, was certified to increase the diffusion rate of components in stationary phase, to reduce the peak width and therfore to intensify the resolution as compared with another customary partitioning agents for use of high temperature. When diethylene glycol succinate on high silica diatomaceous earth was used as the partitioning agent, the peak area ratio of each acetate was confirmed to coincide approximately with weight ratio. The operating condition was discussed and thus the analytical method of unsaturated fatty alcohols prepared by sodium reduction was proposed. Some further illustrations of gas chromatographic analysis were reported.
For the evaluation of dye-dispersing power of surface active agents, semimicro azopigment method has been developed. The method consists of coupling diazonized base with naphthol (mole ratio 1 : 1) in presence of dispersing agent under definite condition at pH 4.5, and measuring an amount of dispersing agent just suffcient to prevent the precipitation of azopigment. Dispersion value is defined as follows; Dispersion value=An amout of dispersing agent enough to prevent precipitation (g) /An amount of azopigment (g) (calcd.) It has been confirmed that the suitable diazo components are : Red KB Base, Red TR Base and p-nitroaniline, and the coupling components : Naphthol AS and Naphthol AS-SW. Among the various dispersing agents examined, sodium alkyl naphthalene sulfonate and sodium naphthalene sulfonate formaldehyde condensate showed most excellent azopigment dispersing power (Dispersion Value 2).
In the studies of performance tests of surface active agents, a new foam test, the “Semimicro Improved TK-Method” has been developed in our laboratory. The method consists of measuring foam volume produced by bubbling 250 ml of air for 60 seconds into 5 ml of test solution. The apparatus and operation have been improved and simplified.
Na-dioctyl-sulfosuccinate, namely Aerosol OT, obtained from dioctylmaleate and NaHSO3, has good wettability. The peroxide-catalyzed addition of diethylphosphite to dioctylmaleate readily afforded dioctyl- (α-diethylphosphono) -succinate. One of the ester groups of phosphonoradical can be saponified at room temperature, and the resulting mono Na-salt dissolves in water and shows good surface activity.
2- (2-Pyridyl) -ethanethiol, obtained by hydrolizing the adduct of thiourea with 2-vinylpyridine using alkali, reacted with various unsaturated compounds, such us dialkyl maleate, α-olefin, oleinic acid, alkyl acrylate and N-alkyl acrylamide. The cationic surfactants were synthesized by reacting these reaction products with ethylbromide. It was found that they were surface active and were also applicable as antistatic finishing agents for synthetic fibers.