Chromium Soaps Research Articles

Spectroscopic and Thermal Behavior of Chromium Soaps

The physicochemical characteristics of chromium soaps (myristate and stearate) were investigated in the solid state (thermal, X-ray, and IR measurements) and in solutions (spectrophotometric measurements). The thermal measurements showed that the decomposition of chromium soaps is a two-step process. The soap decomposed into chromium oxycarboxylate, ketone, and carbon dioxide in the first step and the intermediate oxycarboxylate underwent further decomposition to chromium trioxide in the second step. The results showed that the second step is kinetically of zero order and the values of energy of activation for the first and second steps lie in the ranges 6–7 and 17–18 kcal mol−1, respectively. The X-ray diffraction results showed that these soaps possess double-layer structure with molecular axes slightly inclined to the basal plane. The infrared results revealed that the fatty acids exist with dimeric structure through hydrogen bonding between two molecules of fatty acids whereas the metal-to-oxygen bonds in chromium soaps are not purely ionic but possess considerable covalent character. The results of spectrophotometric measurements also confirmed the somewhat covalent nature of chromium soaps in solutions in dichloromethane.

Conductometric and spectrophotometric studies on chromium soap solutions in benzene‐dimethyl formamide

AbstractCritical micelle concentrations, degrees of dissociation, and dissociation constants of chromium soaps (laurate, myristate, palmitate, and stearate) in a mixture of benzene and dimethyl formamide (7:3, vol/vol) were determined from conductivity measurements. The soaps behave as simple moderate electrolytes in dilute solutions. Critical micelle concentration, limiting molar conductance and dissociation constants decreased with increasing numbers of carbon atoms in the soap molecules. Spectrophotometric results show that metal‐to‐oxygen bonds in chromium soaps are not purely ionic but have some covalent character.

Ultrasonic Determinations of Chromium Soaps in a Benzene-Methanol Mixture / Ultraschallmessungen an Chromseifen in Benzol-Methanol-Mischungen

The various acoustic parameters of chromium soaps in a benzene-methanol mixture were determined by ultrasonic velocity measurements. The results show that chromium soaps behave as weak electrolytes in solutions. The results confirm that there is a significant interaction between soap and solvent molecules in dilute solutions and the values of c.m.c. decrease with increasing chain length of fatty acid constituents of the soap molecule.

Effect of chain length on acoustic behaviour of chromium soap solutions in xylene and methanol mixture

The ultrasonic velocity measurements of solutions of chromium soaps (laurate, myristate, palmitate and stearate) in a mixture of xylene and methanol (4:1 (V/V)) have been used to evaluate various acoustic parameters (adiabatic compressibility, intermolecular free length, specific acoustic impedance, apparent molar compressibility, molar sound velocity, molar sound compressibility, relative association, available volume and solvation number). The results show that there is a significant interaction between soap and solvent molecules in dilute solutions and soap molecules do not aggregate appreciably in dilute soap solutions below the critical micelle concentration.

Viscometric and Ultrasonic Studies on Chromium Soap Solutions

The molar volume, critical micelle concentration, and various acoustic parameters (adiabatic compressibility, intermolecular free length, specific acoustic impedance, molar sound velocity, molar sound compressibility, apparent molar compressibility, relative association, available volume, and solvation number) were evaluated from the density, viscosity, and ultrasonic measurements of the solutions of chromium soaps (myristate, palmitate, and stearate) in a benzene-methanol mixture (4:1 v/v). The molar volumes obtained by using Einstein's and Vand's equations showed a decrease with increasing chain length of the soap molecules. The values of the critical micelle concentration obtained from ultrasonic velocity measurements were found to be in close agreement with those evaluated from viscosity measurements and showed a decrease with increasing chain length of the fatty acid constituent of soap molecules

Viscometric and spectrophotometric studies of chromium soaps in a benzene—dimethylformamide mixture

The viscosity results for solutions of chromium soaps (laurate, myristate, palmitate and stearate) in a benzene—dimethylformamide (4: 1 v/v) mixture were explained on the basis of equations proposed by Einstein, Vand, Moulik and Jones and Dole. The values of molar volume obtained from Einstein's and Vand's plots were found to be in close agreement, and increase with increasing chain length of the fatty acid constituent of the soap molecules. The density and viscosity results show that the soap—soap interactions are almost negligible in dilute solutions. The spectrophotometric measurements show that the metal-to-oxygen bonds in chromium soaps are not purely ionic but possess some covalent character.

Viscometric Investigations on Chromium Soaps in Benzene-Methanol Mixture

The density and viscosity of the solutions of chromium soaps (myristate, palmitate and stearate) in benzene-methanol (4:l V/V) mixture have been measured at a constant temperature 30 ± 0.05 °C). The density and viscosity results have been explained on the basis of equations proposed by Root, Einstein, Vand, Moulik and Jones-Dole. The values of molar volume obtained by using Einstein's and Vand's equations were found to be in close agreement. The results of Root's and Jones-Dole equation confirm that the soap-soap interactions are almost negligible in dilute solutions. The values of CMC for chromium soaps obtained from density and viscosity measurements were in agreement.

Acoustic behaviour of chromium soap solutions in benzene–dimethyl formamide mixture

AbstractThe critical micelle concentration and various acoustic parameters of chromium soaps (myristate, palmitate, and stearate) in a mixture of benzene and dimethyl formamide (4 : 1 v/v) have been determined by ultrasonic velocity measurements. The results showed that the ultrasonic velocity, specific acoustic impedance, molar sound velocity, and molar sound compressibility increase, while intermolecular freelength, adiabatic compressibility, and available volume decrease with increasing concentration and chain length of the soap. The results show that there is a significant interaction between soap and solvent molecules in dilute solutions and the soap molecules do not aggregate appreciably in dilute solutions. © 1993 John Wiley & Sons, Inc.

The behaviour of chromium soaps in non-aqueous solvents

Spectroscopic evidence agrees with vapour pressure osmometry data and indicates that chromium tri-myristate, tri-palmitate and tri-stearate form aggregates of constant size above a distinct concentration. These aggregates are in equilibrium with a constant concentration of monomeric species.

Solutions of soaps in organic solvents

The solubilities of silver and chromium soaps in nonaqueous solvents have been determined by a radiotracer technique. The metal soaps are sparingly soluble in nonaqueous solvents but more soluble in alcohols. The solubility data at different temperatures in benzene, toluene, and m-xylene has been used to determine the critical micelle concentration (c.m.c) of these soaps. Small amounts of methanol enhance the solubility of the metal soaps in benzene and the viscosity of soap solutions in methanol–benzene (15% methanol) showed the existence of micelles at high soap concentrations. The solubility of silver laurate in aqueous solutions of dioctyl sodium sulphosuccinate and Nonidet-P40 has been determined and the data was used to calculate the c.m.c. of aqueous surfactants.

Colloid-chemical studies with nickel and chromium soaps in organic solvents

Viscometric, spectrophotometric and solubility measurements have been made to study the colloidchemical behaviour of chromium and nickel soaps (stearate, palmitate, myristate and laurate) in a number of organic solvents. The experimental results have been sucessfully employed to determine the c.m.c. and the concentration of these metal soaps. Nickel stearate has been found to undergo thixotropic gelation in toluene.

Colloid-chemical studies with nickel and chromium soaps in organic solvents

Colloid-chemical studies with nickel and chromium soaps in organic solvents

Studies on the behaviour of chromium (iii) soaps. II. Solubility and viscometric studies with chromium stearate and palmitate in nonaqueous solutions

AbstractThe colloid chemical behaviour of the chromium stearate and palmitate in nonaqueous solutions have been investigated by solubility and viscometric methods. Chromium stearate and palmitate form no micellar aggregate in pyrindine but aggregate into micelles in benzene, toluene, xylene and carbon tetrachloride in the concn range of ca. 0.7舑1.5ȕ10蜢2 mole/liter. Viscometric studies can be utilized in estimating the concn of the metal soaps in fairly concd solution: 0.822舑27.431 g/liter.

Studies on the behaviour of chromium (iii) soaps. I. Spectrophotometry of chromium stearate and palmitate in nonaqueous solutions

AbstractStudies on the spectrophotometry of chromium stearate and chromium palmitate in benzene, toluene, xylene, carbon tetrachloride and pyridine solvents provide evidence for the existence of complex ion formation. It has been found that this property can be applied successfully for the estimation of chromium in the concn range 1 to 11 mM/liter at 425 and 580 mƁ. The method can be employed for the higher concn (> 11 m M/liter) range also but the Beer‐Lambert舗s law is applicable only at 425 mƁ.

Metal soaps of wool wax acids as stabilizers for plasticized polyvinyl chloride

AbstractCopper, magnesium, lead, nickel, cobalt, manganese, iron, chromium, cadmium, and barium soaps of the wool wax acid fraction have been tested as stabilizers for plasticized polyvinyl chloride polymers. Barium, cadmium, and lead soaps performed well in the light stability evaluations. In the heat aging tests barium, magnesium, lead, and nickel soaps were superior while cadmium, and manganese soaps performed poorly. The copper, cobalt, iron, and chromium soaps were ineffective.Two tests for stability were employed: an accelerated light aging test and an accelerated heat aging test. Combinations of barium and cadmium soaps were tested for synergistic effects and found to be more effective as stabilizers than the individual soaps. Soaps made from fractions of acids by partitioning the whole wool wax acid fraction were also tested. Neither the hydroxy nor the non‐hydroxy acid fraction soaps had as goad stabilizing properties for PVC as those of the whole acid fraction.