Synthesis, Spectral and Thermal Studies of o-vanillin Oxime Complexes of Zinc(II), Cadmium(II) and Mercury(II)

Zinc(II), cadmium(II) and mercury(II) complexes of o-vanillin oxime have been synthesized and characterized by different physicochemical techniques. All the complexes have been subjected to non-isothermal decomposition studies in nitrogen atmosphere using thermogravimetry. The kinetic parameters for the decomposition of these complexes were evaluated using different methods and comparatively better results were obtained by these different methods. It has also been found that the decomposition processes of all these complexes follow first order kinetics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermoanalytical study about histidine and cysteine-cadmium interactions

Infrared spectroscopy, thermogravimetry and differential scanning calorimetry techniques were used to study the metal-amino acid interactions for adducts of the general formula CdCl₂·nL (n=1.0 or 1.5 and L=histidine or cysteine). After characterization the thermal degradation process was kinetically followed by a non-isothermal method. The infrared data confirmed that the cation is coordinated the carboxylic oxygen atoms of the amino acid molecules. The thermogravimetric results indicated that the main step of the thermal degradation of all amino acid adducts is connected to the rupture of the metal-ligand bonds, to give the associated activation energies values of 77, 44, 55 and 41 kJ mol^-1 for CdCl₂·nL, n=1.0 and 1.5, for histidine and cysteine, respectively. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molten lithium carbonate—sodium carbonate—potassium carbonate eutectic: The reaction of six first row transition metal cations

The reactions of manganese(II), iron(II), iron(III), cobalt(II), nickel(II) and copper(II) chlorides with the molten alkali metal carbonate eutectic have been studied by thermogravimetry. The insoluble products (binary or ternary metal oxides) have been identified by X-ray diffraction and reaction stoichiometries are suggested. Nickel(II) solutions were sufficiently stable for electronic spectroscopy and indicated, as did thermogravimetry, that addition of potassium chloride did not cause significant formation of chloro complexes.     

Complexes of cobalt(II), nickel(II) and copper(II) with the benzenedicarboxylic acids. Thermal properties

The thermal properties of the complexes of phthalic, isophthalic and terephthalic acid with cobalt(II), nickel(II) and copper(II) are determined by thermogravimetry (TG), differential thermogravimetry (DTG) and differential scanning calorimetry (DSC).The thermal stability of the anhydrous compounds gives, for the metal ions, a sequence Co > Ni > Cu.The thermal stability series as a function of the ligand for each metal is terephthalate > isophthalate > phthalate.     

Thermal Behavior,Nonisothermal Decomposition Reaction Kinetics of Mixed Ester Double-base Gun Propellants

The thermal decomposition behavior and nonisothermal reaction kinetics of the double-base gun propellants containing the mixed ester of triethyleneglycol dinitrate（TEGDN） and nitroglycerin（NG） were investigated by thermogravimetry（TG） and differential thermogravimetry（DTG）, and differential scanning calorimetry（DSC） under the high-pressure dynamic ambience. The results show that the thermal decomposition processes of the mixed nitric ester gun propellants have two mass-loss stages. Nitric ester evaporates and decomposes in the first stage, and nitrocellulose and centralite II（C2） decompose in the second stage. The mass loss, the DTG peak points, and the terminated temperatures of the two stages are changeable with the difference of the mass ratio of TEGDN to NG. There is only one obvious exothermic peak in the DSC curves under the different pressures. With the increase in the furnace pressure, the peak temperature decreases, and the decomposition heat increases. With the increase in the content of TEGDN, the decomposition heat decreases at 0.1 MPa and rises at high pressure. The variety of mass ratio of TEGDN to NG makes few effect on the exothermic peak temperatures in the DSC curves at different pressures. The kinetic equation of the main exothermal decomposition reaction of the gun propellant TG0601 was determined as： dα/dt=1021.59（1-α）3e-2.60×104/T. The reaction mechanism of the process can be classified as chemical reaction. The critical temperatures of the thermal explosion（Tbe and Tbp） obtained from the onset temperature（Te） and the peak temperature（Tp） are 456.46 and 473.40 K, respectively. ΔS≠, ΔH≠, and ΔG≠ of the decomposition reaction are 163.57 J·mol^-1·K^-1, 209.54 kJ·mol^-1, and 133.55 kJ·mol^-1, respectively.     

Thermal characterization of mangaba-based films

The purpose of this study was to evaluate the physical–chemical properties of starch (SF), mangaba (MF), and mangaba/starch-based films (MSF), using differential thermal analysis, thermogravimetry/derivative thermogravimetry, infrared spectroscopy, mechanical profile, and scanning electron microscopy. The films were prepared by casting process using sucrose and propyleneglycol as plasticizers. The thermal profiles of MF and MSF were similar and showed increased thermal stability. The mechanical properties of MF and MSF presented decreases of tensile strength and elastic modulus when compared with SF. The MSF showed the best thermal and mechanical characteristics.     

Kinetics and mechanism of the non-isothermal decomposition: I. Some divalent cross-linked metal-alginate ionotropic gels

The kinetics of thermal decomposition of Sn(II), Pb(II), Cd(II) and Hg(II) alginate gels have been studied using thermogravimetry (TG) and derivative thermogravimetry (DTG) in static air. The thermal dehydration of each gel complex was found to occur in one step, whereas the decomposition of the dehydrated complexes occurred in two steps. The kinetic parameters were computed by different models and a tentative decomposition mechanism consistent with the kinetic observations is discussed.This revised version was published online in November 2005 with corrections to the Cover Date.     

Thermal analysis of fly ash-based zeolites

The paper presents research results on dehydration properties and thermal behaviour of zeolites synthesized from fly ash, applying TG (thermogravimetry), DTG (derivative thermogravimetry) and SDTA (simultaneous differential thermal analysis) methods. In result of the analysis conducted water contents in zeolite samples were defined. On the basis of the data obtained from the thermogravimetric analysis, thermal behaviour of zeolites was assessed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Solid-state compounds of 2-chlorobenzylidenepyruvate with some bivalent metal ions

Solid-state M-2-Cl-BP, where M stands for Mn, Fe, Co, Ni, Cu, Zn and Pb and 2-Cl-BP is 2-chlorobenzylidenepyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), simultaneous thermogravimetry and differential thermal analysis (TG-DTA), X-ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, thermal stability and thermal decomposition of the isolated compounds.     

鲍鱼多糖Hal-A的热分析研究

采用热重、热重-红外谱联用及差示扫描量热法，对鲍鱼多糖进行热分析研究 ，结果表明鲍鱼多糖在空气和氮气氛中，230 ～ 340 ℃之间发生剧烈的分解反应 。氮气氛中，是吸热的分解过程；而空气氛中，是放热氧化反应，并且在453 ℃左 右，有另一个急剧的氧化裂解过程。与淀粉、肝素、甲壳素和半乳糖的热分析比较 ，含有硫酸酯的鲍鱼多糖和肝素热稳定性较低，含氨基的甲壳素最高，这反映出不 同基团对多糖热稳定性的影响。     

Thermal decompositions of some divalent transition metal complexes of triethanolamine

The thermal behaviours of the Ti(II), Mn(II), Fe(II), Ni(II), Cu(II) and Zn(II) complexes of triethanolamine were studied by means of thermogravimetry, differential thermogravimetry, differential thermal analysis infrared spectrophotometry and elemental analysis. The sequence of thermal stability of the metal complexes, determined by using the initial decomposition temperature, was found to be Ti(II)?Mn(II)>Fe(II)>Ni(II)>Zn(II)>Cu(II). Some of the kinetic parameters, such as the activation energy and order of reaction for the initial decomposition reaction, were calculated and the relationship between the thermal stability and the chemical structure of the complexes is discussed.     

Co(II)-exchanged montmorillonite with ethylenediamine,trimethyl- and tetramethyl-ethylenediamine and their thermal decomposition

The influence of different steric properties of ethylenediamine (EDA), trimethylenediamine (TrMeEDA) and tetraethylenediamine (TeMeEDA) on the type of interactions with Co(II)-exchanged montmorillonite and thermal decomposition of these materials were studied. The results of X-ray diffraction (XRD), thermogravimetry (TG), derivative thermogravimetry (DTG) and spectral analysis shows that the studied ethylenediamines are intercalated into the interlayer space of montmorillonite. Thermal decomposition at 20–500 °C of studied samples with EDA proceeds in three steps (the release of chemosorbed amines, coordinated EDA and dehydroxylation) while the sample with TrMeEDA and TeMeEDA in five steps (also release the protonated forms). The effect of different steric properties of individual diamines is evident.     

Coordination Compounds of Cobalt(II), Nickel(II), and Zinc(II) Malonates and Phthalates with Benzohydrazide

Benzohydrazide complexes of cobalt(II), nickel(II), and zinc(II) malonates and phthalates were synthesized and characterized by chemical analysis, IR spectroscopy, diffuse reflectance spectroscopy, and thermogravimetry.     

Coordination compounds of 3d-metal phthalates with semicarbazide

Complexes of cobalt(II), nickel(II), copper(II), and zinc phthalates with semicarbazide were synthesized. The obtained compounds were characterized by the methods of chemical analysis, IR spectroscopy, diffusion reflection spectroscopy, and thermogravimetry.     

Coordination compounds of 3<Emphasis Type="Italic">d</Emphasis>-metal valerates and benzoates with nicotinamide

Complexes of iron(II), cobalt(II), nickel(II), copper(II), and zinc valerates and benzoates with nicotinamide were synthesized. The products were characterized by chemical analysis, IR spectroscopy, diffuse reflection spectroscopy, and thermogravimetry.     

Reactions of Oxides of Some 3d Elements with Ammonium Hydrogen Difluoride

Reactions of iron, manganese(II), manganese(IV), copper, and zinc oxides with ammonium hydrogen difluoride were studied by thermogravimetry, X-ray phase analysis, IR spectrometry, and chemical analysis.     

Coordination compounds of 3d-metals salicylates with thiosemicarbazide

Complexes of copper(II), nickel(II), cobalt(III), zinc(II), and iron(III) salicylates with thiosemicarbazide were synthesized. The resulting compounds were characterized by the elemental analysis data, infrared spectroscopy, diffuse reflectance spectroscopy, and thermogravimetry.     

Thermal analysis of Beypazari lignite

Beypazari lignite was investigated by differential scanning calorimetry (DSC), thermogravimetry (TG), high pressure thermogravimetry (HPTG) and combustion cell experiments. All the experiments were conducted at non-isothermal heating conditions with a heating rate of 10°C min^?1, in the temperature range of 20–700°C. DSC-TG data were analysed using an Arrhenius-type reaction model assuming a first-order reaction. For the HPTG data the Coats and Redfern equation was used for kinetic analysis. In the combustion cell experiments the Fassihi and Brigham approach was used in order to calculate kinetic data. Finally a comparison is made between the kinetic results.     

Thermal properties and reactivity determination of micro- and submicrometer nickel powders

Monodispersed fine metal nickel powders of uniform shape and high purity are increasingly required for specific uses in many technological areas, especially in the preparation of electronic materials such as the manufacture of conductive inks and pastes and the formation of catalysts. Metallic nickel powders were prepared in ethylene glycol by the reduction of a nickel solution. Hydrazine was used as a reducing agent. Metal powders were characterized by chemical analysis, scanning electron microscopy (SEM), thermogravimetry (TG), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). Particle size distributions were determined using laser light scattering. The reactivity and purity of these fine nickel powders were tested by repeated oxidation and reduction of nickel powders in oxidative and reductive atmospheres.     

Coordination compounds of 3d metals malonates and glutarates with thiosemicarbazide

Complexes of copper(II), nickel(II), and cobalt(III) malonates and glutarates with thiosemicarbazide have been prepared and studied by means of elemental analysis, IR spectroscopy, diffuse reflection spectroscopy, and thermogravimetry.