Authors:V. Manríquez, C. Díaz, G. González, and I. Brito
Benzenesulfenamides with the formula R-S-N-(R′)2 (R=C6H5 andR′=NC4H8O, C7H7 and C6H11) and their chromium carbonyl complexes were studied by means of TG and mass spectrometric methods. The thermal behaviour of the compounds the stabilities of free sulfenamides are lower than those observed for the corresponding chromium carbonyl complexes. Combined thermogravimetry — mass spectrometry results suggest that the fragmentation mechanism of the carbonyl complexes involves cleavage of the Cr-S and Cr-CO bonds while that of sulfenamide depends mainly on the dissociation rates of the NR2 groups.
Thermal behaviour of blends based on N,N'-bis(4-itaconimidophenyl) ether (IE) and 4,4'-bis(4-allyl-2-methoxyphenoxy) benzophenone
(R1) or 4,4'-bis(2-allylphenoxy) benzophenone (R2) are described in this paper. The reactive diluent content was varied from 5-50% (mass/mass) in these blends. A decrease
in the melting point and exothermic peak temperature was observed with increasing mass percent of reactive diluent. Thermal
stability of blends was affected at high mass percentage of reactive diluents.
Authors:S. Tarulli, O. Quinzani, J. Dristas, and E. Baran
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.
Authors:Amanda dos Santos, G. Chierice, A. Riga, K. Alexander, and Ellen Matthews
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.
Authors:P. Espeau, B. Nicolaï, R. Céolin, M. Perrin, L. Zaske, J. Giovannini, and F. Leveiller
Investigation into the thermal behavior of orthorhombic Forms I and II of spironolactone, by means of differential scanning
calorimetry and high-resolution X-ray powder diffraction, showed that Form I melts then recrystallizes into Form II at 373–393
K, i.e. in the temperature range within which high resolution X-ray powder diffration showed that Form I transforms into Form II.
Refinements of the lattice parameters of the two forms indicated that Form I is denser than Form II in the range from 298
K up to the temperature at which it melts.
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.
Authors:Rodica Olar, Mihaela Badea, Dana Marinescu, and Ramona Mardale
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 thermalbehaviour of these derivatives was
Thermal behavior of α-(Cu–Al–Ag) alloys, i.e. alloys
with composition less than about 8.5 mass% Al, was studied using differential
scanning calorimetry (DSC), differential thermal analysis (DTA), scanning
electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray
diffractometry (XRD). The results indicated that the presence of silver introduces
new thermal events ascribed to the formation of a silver-rich phase and, after
addition higher amounts than 8 mass% Ag to the Cu–8 mass% Al alloy it
is possible to observe the formation of the γ1
phase (Al4Cu9), which is only
observed in alloys containing minimum of 9 mass% Al. These results may be
attributed to some Ag characteristics and its interaction with Cu and Al.
The thermal behaviors of three pentaerythritol tetranitrate (PETN) base polymer bonded explosives (PBX), Detasheet A (EL506A,
red) and Datasheet C (EL506C, yellow-green) that supply by DuPont Co., PBXN-301 were investigated using thermal techniques
in this work. The thermal properties of PETN base polymer bonded explosives, such as vacuum thermal stability (VTS), time
to ignition, auto-ignition and shelf life of PBX that calculation from Arrhenius equation by the length of time for 5% decomposition
were also examined. By comparing the thermal properties, VTS and shelf life of PETN base polymer bonded explosives, the application
and storage of Datasheet C (EL506C, yellow-green) should be considered carefully, owing to the ingredients of Datasheet C
(EL506 C, yellow-green) containing nitrocellulose. Binders that using in this study seems play no significant effect on the
decomposition for polymer bonded explosives, because the decomposition temperature of binders is always higher than that of
Authors:X. Han, Y. Hu, Z. Lin, S. Li, F. Zhao, Z. Liu, J. Yi, L. Zhang, and X. Ren
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.