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Abstract  

Complexes of Cu(II) with substituted o-acetoxy benzoic acids (5-haloaspirines, X-asp) with and without pyridine (py), of composition [Cu2(X-asp)4] and [Cu(X-asp)2(py)2 ] have been synthesized and characterized. Electronic and vibrational spectroscopic data of these complexes are reported. Its thermal behaviour was investigated by thermogravimetry and differential thermal analysis. In all complexes, the haloaspirinate ligands decompose in two or three steps, starting with the break up of the coordinated acetoxy groups. CuO is obtained as the final pyrolysis residue in all cases.

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Abstract  

Thermal behavior of four food dyes, i.e. tartrazine, crysoine, azorubine and amarant was studied under non-isothermal conditions, in dynamic air atmosphere and at heating rates of 5, 10, 15 and 20C min–1. The TG data were correlated to the FTIR spectra of each sample, before and after the thermal decomposition. Kinetic study by processing the TG data was performed. The main conclusion of this study is that the non-parametric kinetic method allows a separation of the steps of a complex process and that the values of the activation energy obtained by this method agree satisfactory with that of Flynn–Wall–Ozawa estimation.

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Abstract  

Eugenol is an allyl chain-substituted guaiacol in the biosynthesized phenylpropanoid compound class derived from Syzygium aromaticum L. and widely used in folk medicine. Nonetheless, its pharmacological use is limited by some problems, such as instability when exposed to light and high temperature. In order to enhance stability, the eugenol molecule was structurally modified, resulting in eugenyl acetate. The eugenyl acetate’s thermal behavior and crystal structure was then characterized by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) and compared to a commercial sample.

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Journal of Thermal Analysis and Calorimetry
Authors: Hong-Ling Li, Koichi Takahashi, Yusuke Ujihira, Mariko Ishiwatari, Kurima Kobayashi, Takahiko Iriyama, and Tokuzo Konishi

Abstract  

The Mössbauer spectra of Sm2Fe17Nx, prepared by the nitrogenation of Sm2Fe17 powders in an ammonia and hydrogen atmosphere, were observed at elevated temperatures to shed light on the thermal behavior of nitrogen in the compounds Sm2Fe17Nx. It was found that there were large differences in thermal behavior between the starting Sm2Fe17, crystalline Sm2Fe17Nx (x≈1.7) and amorphous Sm2Fe17Nx(x∼7). The thermal decomposition behavior of Sm2Fe17N3.2, developed as one of the most promising hard magnetic materials, was found to be different under different atmospheres.

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derivatives, new complexes with such units incorporated in Schiff bases ligands have been synthesized and characterized. The complexes have been characterized by different analytical and spectral methods. The thermal behaviour of these derivatives was

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Abstract  

A series of new complexes with mixed ligands of the type [ML(C3H3O2)2nH2O (((1) M=Mn, n=1; (2) M=Co(II), n=2; (3) M=Ni(II), n=4; (4) M=Cu(II), n=1.5; (5) M=Zn(II), n=0; L=3-amino-1,2,4-triazole and (C3H3O2)=acrylate anion) were synthesized and characterised by chemical analysis and IR data. In all complexes the 3-amino-1,2,4-triazole acts as bridge while the acrylate acts as bidentate ligand except for complex (5) where it is found as unidentate. The thermal behaviour steps were investigated in nitrogen flow. The thermal transformations are complex processes according to TG and DTG curves including dehydration, acrylate ion and 3-amino-1,2,4-triazole degradation respectively. The final products of decomposition are the most stable metal oxides, except for complex (4) that leads to metallic copper.

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Abstract  

Effects of fullerenes including FS, EFS and pure C60 on thermal behaviors of polyethylene glycol (PEG) have been studied by employing thermogravimetry-differential thermogravimetry (TG-DTG), differential scanning calorimeter (DSC) and off-line furnace-type pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The products were collected by Cambridge filter pad which was widely used in analyzing the combustion products of cigarette. The results showed that the addition of fullerenes obviously restrained the thermal decomposition of PEG. The initial decomposition temperatures (IDT) and maximum decomposition peak temperatures (MDT) were evidently postponed by the addition of fullerenes. Pyrolysis products with one or two hydroxyl end groups obviously increased with the addition of 10% C60. The reasons of the changes were discussed from the aspects of reaction mechanisms.

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The thermal behaviour of the square-planar dithiocarbazate derivative complexes Pt[NRNC(S)SR']2 (R=n-hexyl, R′ = methyl or benzyl) has been investigated.

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Abstract  

Urea–formaldehyde (UF) and phenol–formaldehyde (PF) resins are the most widely used wood adhesives. The first stage in resin manufacturing is the formation of methylol derivatives which polycondensation leads to building the tridimensional network. Understanding the behaviour of methylol compounds in curing provides useful information for developing appropriate resin structures. Thermal behaviour of N,N′-dihydroxymethylurea, 2- and 4-hydroxymethylphenols, urea and phenol as model compounds for UF, PF and phenol–urea–formaldehyde (PUF) resins was followed by TG-DTA method. The measurements were carried out by the labsys instrument Setaram at 30–450 °C in nitrogen flow. The characteristic signals for model compounds and for some reaction mixtures were measured by high resolution 13C NMR spectroscopy.

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Abstract  

Thermal behaviour of the glass series (100–y)[0.5ZnO0.1B2O30.4P2O5]yTiO2 (with y=0–39 mol% TiO2) was investigated by DSC and TMA. The addition of TiO2 results in a non-linear increase of glass transition temperature. The compositional dependences of thermal stability, evaluated by two criteria exhibit two maxima for the glasses doped with 10.7 and 35.9 mol% TiO2. All the glasses crystallize on heating in the temperature range of 576–670C. The crystallization mechanism was studied at the glasses with 19.4 and 35.9 mol% TiO2 and the results showed that surface nucleation mechanism prevails in these glasses over the internal one.

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