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Abstract
Thermal treatment of torasemide form A resulted in several effects which were divided into five steps. These were investigated and discussed applying TG-MS and TG-FTIR with additional information derived from SEM, hot-stage and FTIR microscopy. The investigated crystal form of torasemide represents a mixed solvate including ethanol and water. Its desolvation, the solid-solid transformation into the anhydrate mod. II and the melting of this anhydrate is elucidated using thermal analysis and microscopic observations (FTIR and hot-stage microscopy). The released and evaporated solvents were determined with coupled techniques. On further heating the structural identification of evolved gases allowed the analysis of the degradation pathway of torasemide up to 340C.
Summary
Thermal behavior of commercial PVC cable insulation both before and after extraction of plasticizers, fillers and other agents were tested by TG/DTG and DSC during heating in the range 20-800C in air. The ultrasound enhanced hexane extraction and dissolution in THF with subsequent precipitation of PVC were used to prepare 'extracted' and 'precipitated' samples. The total mass loss measured for the 'non-treated', 'extracted' and 'precipitated' PVC samples was 71.6, 66.6 and 97%, respectively. In the temperature range 200-340C the release of dioctylphthalate, HCl and CO2was observed by simultaneous TG/FTIR. From TG results measured at different heating rates (1.5, 5, 10, 15 K min-1) in the range 200-340C the non-isothermal kinetics of the PVC samples degradation was determined. Activation energy values of the thermal degradation processes calculated by ASTM E 698 method, for 'non-treated', 'extracted' and 'precipitated' PVC samples were 174.617 kJ min-1, 192.819 kJ min-1, 217.120 kJ min-1, respectively. These kinetic parameters were used for the lifetime simulation of the materials.
−1 stream of pure oxygen prior to entering a 900 °C combustion furnace. Thermogravimetry-Fourier transform infrared spectra The TG-FTIR instrument consists of TG analyzer (TGA-Q5000, TA Company, USA
,2,3-tricarboxylic acid. In our work the results of the TG-FTIR, TG-MS and DSC analyses of the three acids studied are presented. Experimental Materials All reagents: citric acid, C 6 H 8 O 7 , (ACS reagent, ≥99
coated on the surface of cotton fabrics. The purpose of this research was to investigate the influence of the hybrid coating on thermal properties of cotton fabrics. The characteristics were evaluated through TG, TG-FTIR, and MCC experiments
in a ceramic crucible up to 850 °C at a heating rate of 10 °C min −1 in dynamic air atmosphere ( v = 0.75 dm 3 h −1 ). For kinetic measurements, the heating rates: 5, 2.5 and 1.25 °C min −1 were applied. The TG–FTIR coupled measurements
Abstract
Ammonium nitrate (AN) is one of the main nitrogen fertilizers used in fertilization programs. However, AN has some serious disadvantages — being well soluble in water hardly 50% of the N-species contained are assimilated by plants. The second disadvantage of AN is associated with its explosive properties. The aim of this paper was to clarify the influence of different lime-containing substances — mainly Estonian limestone and dolomite — as internal additives on thermal behaviour of AN. Commercial fertilizer grade AN was under investigation. The amount of additives used was 5, 10 or 20 mass%, or calculated on the mole ratio of AN/(CaO, MgO)=2:1 in the blends. Experiments were carried out under dynamic heating condition up to 900°C (10°C min−1) in a stream of dry air or N2 by using Setaram Labsys 2000 equipment coupled to Fourier transform infrared spectrometer (FTIR). The results of analyses of the gaseous compounds evolved at thermal treatment of neat AN indicated some differences in the decomposition of AN in air or in N2. At the thermal treatment of AN’s blends with CaCO3, MgCO3, limestone and dolomite samples the decomposition of AN proceeds through a completely different mechanism — depending on the origin and the content of additives, partially or completely, through the formation of Mg(NO3)2 and Ca(NO3)2.
Abstract
Approximately one million tons of semicoke (SC) is formed and stored in open air dumps every year in the production of shale oil by processing Estonian oil shale (OS). The content of different harmful compounds as sulphides, PAH, phenols, etc. in SC make these dumps one of the most serious sources of environmental contamination. The aim of this work was to study the behaviour of sulphur compounds in OS and its SC, formation of SO2 and possibilities of binding it into the solid phase during thermooxidation of fuel blends based on SC. Blends modified with SC ash addition were studied as well. It was determined that SO2 emission in thermooxidation of SC samples started at 280-300C and proceeded with a steady speed up to 580-600C and the amount of sulphur evolved was 5-10% from the total content of sulphur in the sample. The amount of SO2 emitted decreased depending on the mass ratio of the composite fuels from 49-56 to 15-35% during thermooxidation of OS samples studied or their blends with SC, respectively, from 43-80% for coal samples to 13-60% for their blends with SC and to 2-13% during thermooxidation of these blends modified with SC ash addition. In the products of thermooxidation formed at 800-900C the only sulphur containing phase was CaSO4, at 650C also traces of CaS and CaMg3(SO4)4 were fixed.
polymers. The aim of this study is to investigate the thermal decomposition of TFR and its polymer metal complexes using TG-FTIR-MS. Experimental Materials Thiourea, formaldehyde (37% aqueous solution), and
. Results and discussions XRD, BET, and DTA–TG analysis The structure of milled molybdenum and vanadium oxides and their composition was analyzed with the help of XRD, DTA–TG, FTIR, and Raman spectroscopy in our previous
