The thermal behaviour of divalent and higher valent metal soaps: a review

Akanni, M. S.; Okoh, E.; Burrows, Hugh D.; Ellis, Henry A.

doi:10.1016/0040-6031(92)80150-u

Cited by 104 publications

(154 citation statements)

References 307 publications

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“…The remaining compound at the end of thermal treatment could be oxide and carbonate of zinc metal. 1 Although the analysis of decomposition products was not performed, it was thought that major decomposition products of ZnSt 2 were carbon dioxide, alkanes, and ketones as gas products. 17 As pointed out by Jaw et al, 18 stearic acid decomposed giving 5% in weight carbonaceous residue as seen in Figure 6.…”

Section: Resultsmentioning

confidence: 99%

“…Melting points of certain soaps have been reported differently because of impurities in the product. 1 Synthesis and characterization of iron stearate compounds was reported by Abrahamson and Lukaski. 10 The structure and transition behavior of ZnSt 2 by infrared and XAFS spectroscopies were investigated by Ishioka et al 11 From XAFS analysis, the coordination number of the carboxylate group around the zinc atom was evaluated as 4 and the Zn-O distance was 1.95 Å.…”

Section: Introductionmentioning

confidence: 99%

“…1 Zinc stearate (ZnSt 2 ) is one of the important ionic surfactants of metal soaps. In addition to the aforementioned applications, ZnSt 2 has been recently used in preparation of Langmuir-Blodgett (LB) mono-and multilayers.…”

Section: Introductionmentioning

confidence: 99%

“…Considering some of the metals give no reaction with organic acids, and the absence of pure metals in nature, the first two processes are generally preferred for pure product manufacturing. 1 The precipitation process generally produces metallic soap by the reaction of an aqueous solution of a watersoluble metal salt and a fatty acid alkali metal salt at a temperature below the boiling point of water under atmospheric pressure. Filtering, washing, and drying are the important steps in this method.…”

Section: Introductionmentioning

confidence: 99%

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Zinc Stearate Production by Precipitation and Fusion Processes

Gönen

Balköse

İnal

et al. 2005

Ind. Eng. Chem. Res.

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In this study, the production of ZnSt 2 using sodium stearate and zinc sulfate in a precipitation process, and stearic acid and zinc oxide in a fusion process, was investigated with regard to product purity. In the fusion process, an increase in mixing rate decreased the induction time occurring at the beginning of the reaction. While the melting point of the zinc stearate prepared by the precipitation process was found to be about 122°C by optical microscopy, it was slightly lower than 122°C for zinc stearate produced by the fusion process. Differential scanning calorimetry (DSC) indicated onset of melting at 120°C and 118°C for samples prepared by precipitation and fusion processes, respectively. Characteristic peaks of ZnSt 2 were present in XRD patterns of the products obtained by both processes. From SEM micrographs, it was seen that zinc stearate obtained by both processes had lamellar structure.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Zinc Stearate Production by Precipitation and Fusion Processes

Gönen

Balköse

İnal

et al. 2005

Ind. Eng. Chem. Res.

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“…The reason for this higher remaining mass for samples containing ZnSt 2 is the effect of zinc on degradation behaviour. Since thermal decomposition products of ZnSt 2 are ZnCO 3 and ZnO [19,20] on heating it could increase the amount remained from the decomposition of paraffin wax slightly. As the content of ZnSt 2 in paraffin wax is maximum 0.5%, the ZnO and ZnCO 3 that would form from ZnSt 2 would be much smaller than 3-7%.…”

Section: Energy Changes During Heatingmentioning

confidence: 99%

The effect of zinc stearate on thermal degradation of paraffin wax

Gönen

Balköse

İnal

et al. 2008

J Therm Anal Calorim

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Petroleum waxes are complex mixtures of high molecular mass saturated hydrocarbons. These hydrocarbon mixtures mainly consist of n-, iso-, and cyclo-alkanes and traces of aromatic and hetero-analogous compounds in the range of C16-C65 [1,2]. They are mainly divided into two groups, macrocrystalline and microcrystalline waxes, according to their structural constituents. In refining industry, waxes are obtained as a by-product in lubricating oil manufacturing process. As paraffin waxes have excellent properties, such as water-repellency and lubricity they find a wide range of applications including paper and chipboard production, packaging materials, cosmetic and pharmaceutical industries, and plastic industries [2]. Apart from these, they are also used as a component of binder system in ceramic processing, metal powder molding and metal injection molding [3,4]. A technical grade paraffin wax was used as phase change material in deposition of solar energy due to its high latent heat of melting (i.e., 190 kJ kg -1 ) [5]. In most of its applications, thermal decomposition takes place during processing or sintering, such as ceramic or metal powder molding. Another use of paraffin wax is solid fuel for rocket systems. Recently, it has been studied as a high regression rate propellant. It is a candidate for rocket solid fuel, which is expected to replace the conventional rocket fuels, such as cryogenic combustible gases; polymethyl methacrylate (PMMA), high density polyethylene (HDPE), due to its low cost, reduced complexity and increased performance. It has been pointed out that paraffin wax regression rate is about 0.100 cm -1 , which is five times greater than the other solid hybrid fuels [6]. The thermal decomposition kinetics of RP-1 rocket propellant, which consists of paraffins, olefins and aromatics, was investigated between 375-500°C. Thermal decomposition kinetics of RP-1 was assumed to occur by first order reaction [7].Paraffin molecules having different chain length behave similarly towards most of the reactants under similar reaction conditions. When they are heated, they start to degrade into smaller chain lengths. The degradation of petroleum based material is assumed as first order reactions [8].The chain length can be decreased by high temperature treatment and solids having metal ions that act as catalysts. Paraffins in oxidizing media at high temperature undergo simultaneous pyrolysis and oxidation reactions. Pyrolysis of n-hexadecane, considered as paraffinic substance, was studied by Watanabe et al. at 500-550°C in a batch type closed reactor [9]. There were five elementary reaction groups in the pyrolysis of n-hexadecane; initiation, isomerization, b-scission, H-abstraction and termination. In this mechanism, n-alkanes were produced from H-abstraction and l-alkenes are formed via b-scission [9]. Polyethylene which is a polymeric paraffin was converted to liquid and wax products using zeolite with concentrations up to maximum mass by 50% [10]. Organometallic compounds are added to fuels in small qu...

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Iron(II) Metallomesogens Exhibiting Coupled Spin State and Liquid Crystal Phase Transitions near Room Temperature

Seredyuk

Gaspar

Ksenofontov

et al. 2008

Adv Funct Materials

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Reaction of the ligand 2,2,2‐tris(2‐aza‐3‐((5‐akloxy)(6‐methyl)(2‐pyridyl))prop‐2‐enyl)ethane (Cn‐tameMe) with Fe(X)2 · sH2O salts afforded a series of spin crossover metallomesogens with general formula [Fe(Cn‐tame)](X)2 · sH2O (s ≥ 0), with n = 6, 10, 12, 14, 16, 17, 18, or 20 and X = ClO4− or BF4−. Single crystal X‐ray measurements have been performed on the [Fe(C6‐tameMe)](ClO4)2 (C6‐1) derivative at 100 K. The complex C6‐1 crystallizes in the triclinic system and adopts the Pbca space group. The iron(II) ion is in a distorted octahedral environment shaped by three imine and three pyridine nitrogen atoms of the Cn‐tameMe ligand. The average Fe–Nim and Fe–Npy bond distance is 1.918(2) Å and 2.084(2) Å, respectively, which are characteristic for the Fe(II) ion in the LS state. Neighbor molecules are packed in a head‐to‐head fashion forming a layered microsegregated structure. Ionic layer is composed of cationic spin crossover head‐groups and perchlorate anions, whereas alkyl tails are arranged into a non‐polar hydrocarbon layer. The complex [Fe(C18‐tameMe)](ClO4)2 (C18‐1) and the series [Fe(Cn‐tameMe)](BF4)2 (n = 10, 12, 14, 16, 17, 18, 20) (Cn‐2) series show thermally driven spin crossover and mesomorphism above 300 K. The thermotropic behavior of compounds Cn‐2 depends on the chain length defined by n. A common structural feature among all homologues of the series is a similar layered structure and adoption on melting of a smectic mesophase at ca. 350–375 K. Formation of the mesophase is due to the melting of the alkyl chains rather than a rearrangement of the ionic bilayers composed of polar SCO cations and BF4− or ClO4− anions. This gives rise to a mesophase with molten alkyl chains but with restricted movement through the ionic layer. Compounds Cn‐2 show thermochromic properties, they are dark violet in the LS state (T < 275 K, Cr) and become red in the HS state (T > 275 K, Cr, SX). These bi‐functional materials combine spin state change and mesomorphic behavior in a narrow interval of temperatures, 300–375 K.

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The thermal behaviour of divalent and higher valent metal soaps: a review

Cited by 104 publications

References 307 publications

Zinc Stearate Production by Precipitation and Fusion Processes

Zinc Stearate Production by Precipitation and Fusion Processes

The effect of zinc stearate on thermal degradation of paraffin wax

Iron(II) Metallomesogens Exhibiting Coupled Spin State and Liquid Crystal Phase Transitions near Room Temperature

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