Acid Lithium Salt Research Articles

Extraction of wheat flour proteins with sodium dodecyl sulfate and their molecular weight distribution.

By extraction of wheat flour with sodium dodecyl sulfate (SDS) solution at pH 6.8, about 76% of the total flour nitrogen solubilized into clear supernatant. This solvent was more effective for extraction of wheat protein than 0.01 m acetic acid, aluminium lactate-lactic acid buffer (pH 3.1), AUC-solvent (0.1 m acetic acid, 3 m urea and 0.01 m cetyltrimethyl-ammomum bromide) and 3,5-diiodosalicylic acid lithium salt etc. The molecular weight distribution of the SDS-soluble proteins was studied by SDS-polyacrylamide gel electrophoresis and by molecular sieve chromatography on controlled pore glass (CPG–10–500) without prior reduction of disulfide linkages of the proteins. Most of the SDS-soluble proteins had molecular weight of less than 75,000, suggesting single-chained proteins. A small amount of relatively high molecular weight proteins which contained intermolecular disulfide linkages was also detected in the gel of electrophoresis, while high molecular weight protein which did not migrate into gel matr...

Radiolysis of Dicarboxylic Acid Lithium Salt with Neutron Irradiation

A series of dicarboxylic acids of Li—(CH2)n (COOLi)2, n= 0–5, i.e., Li-oxalate, malonate, succinate, -glutalate, -adipate and -pimelate, was irradiated with mixed radiations in a nuclear reactor. The subject of study was the decarboxylation and the reaction of labelling with T atoms brought about by the exposure of the dicarboxylic acid lithium salts to neutrons. The T-labelled hydrocarbons were determined by radiogaschromatography, while gaschro- matography was used to measure macroscopic amounts of compounds. The gaseous products of radiolysis produced from the neutron irradiation of dicarboxylic acid lithium salt were CO2, CO and hydrocarbons. The yield of CO2 from the different dicarboxylic acid lithium salts was higher than obtained from γ-ray irradiation, and decreased with increasing number of methylene groups in the original salt. Also, while with γ-radiolysis, CO is only generated in negligibly small amounts, it was found quite significant in the present case of neutron irradiation. The yield of ...

Dilatometric investigation of phase transitions and structures of anhydrous soaps

The molar volume of a number of anhydrous soaps consisting of straight and branched carbon chains has been measured as a function of the temperature between 25 °C and the melting point of the soap concerned. In the homologous series of the straight-chain soaps investigated (sodium and lithium salts of fatty acids with chain lengths from 11 to 19 and 14 to 18 carbon atoms respectively) a significant “even — odd” alternation of the molar volume in the crystalline state and of the volume changes at all phase transitions up to about 250 °C was found. These results indicate the existence of different structures in the series of the even and odd numbered anhydrous sodium and lithium soaps, both in the crystalline and in the mesomorphic phases. It is assumed that the structural differences are due to different modes of hydrocarbon chain packing. This assumption is supported by an analysis of the magnitude of the transition dilatations, which indicates the presence of ordered chain structures in the mesomorphic soap phases (“ribbon”-structure). It is suggested that the hydrocarbon chains in these structures possess a lowdegree of order in lateral directions, but a high degree of order in the packing of the methyl end groups. Including results reported in the literature, it has been found that the magnitude of the molar melting dilatation in the series of alkali metal stearates strongly decreases with increasing size of the cation, and is significantly lower than that of other paraffinic compounds. It is concluded, that due to theCoulomb forces between the polar groups, the molecules in the melt of anhydrous soaps are more closely packed than in the melt of other long-chain compounds. This applies also to the branched-chain soaps investigated (sodium salts of 2-methyltetradecanoic and 2-methylhexadecanoic acid) in which the number and temperature of the phase transitions are considerably lower and the molar melting dilatation is slightly lower than in straightchain soaps having the same chain length.

A study of the surface tension of the systems: “Water-lithium soaps and butanol-I”

The surface tension of the solutions of lithium salts of fatty acids in the mixtures of water and butanol-I of varying composition has been studied. It has been suggested that the change in the nature of the micelles takes place at about 50% butanol-I concentration. Up to 50% butanol-I concentration hydrophilic oleomicelles are formed but above 50% butanol-I concentration lipophilic hydromicelles exist. A study of the effect of the concentration of the different soaps on the surface tension suggests that the surface tension of the solutions increases with the increase in the soap concentration. It has also been observed that the surface tension of the soap solutions increases with the increase in the number of carbon atoms in the soap.

Helix–random chain transitions of polyamino acids in organic acid–salt solutions

AbstractPolyamino acids which are soluble and helical in acetic acid and dichloroacetic acid (DCA) have been observed to undergo a helix to random chain transition upon the addition of lithium salts of strong acids. The transition can be reversed by diluting the salt. Apparently only lithium cations are able to bring about the polycarbobenzoxy‐L‐lysine (PCBL) transition in acetic acid, whereas the anions display a varying degree of effectiveness; ClO4− > Br− > TSA− > Cl− > NO3−. The lithium salts of carboxylate anions such as OAc− and TFA− do not cause polymer unwinding in acetic acid. Neither do the acids, TSA, HCl, TFA, or DCA induce the transformation in acetic acid. Poly‐L‐alanine (PLA) in DCA unfolds as LiBr is added, but does not unfold in the presence of 0.5M (CH3)4NBr, 0.25M CsBr, or 0.32M HCl. These results are explained on the basis of a direct interaction of the lithium salt with the polymer amide groups to form an ion‐pair complex. The extent to which the union of the ion pair can dissociate from the complex in the low dielectric constant, environment determines the degree of unfolding of the polymer. The anion dissociation equilibrium presumably therefore would lie in the same order as given above. Acids such as HCl and TSA are considered to substantially protonate and ion‐pair with the polymer, but do not readily dissociate the anion partner from the complex, and therefore do not produce an unstable positively charged helical structure.

Use of synthetic branched carboxylic soaps in the emulsion copolymerisation of styrene and butadiene

AbstractSodium soaps of highly branched saturated monocarboxylic acids, in particular those containing 15–20 carbon atoms, are valuable substitutes for both rosin acid soaps and sodium stearate in cold emulsion polymerisation SBR recipes such as ASTM types 1500, 1502, and 1509. Indications are that they possess various process advantages over the normal types of emulsifier. At comparable concentrations they give higher rates of polymerisation than do the commercially available rosin acid emulsifiers and their solutions do not gel at temperatures between 5° and 20°, as is the case with sodium stearate. Moreover, they show a relatively good tolerance towards hard water.Potassium, ammonium and lithium salts of these synthetic acids are also excellent emulsifiers for the preparation of SBR latices.