The results of thermoanalytical investigations of polyimides are considered. It is shown that combined application of methods of thermal analysis makes it possible not only to determine the thermal and structural characteristics of polyimide articles but also to observe the formation of polyimides, their thermal degradation and transformation into new structures under the influence of high temperatures.
of this study is to understand some properties and thermal behavior of blood,
giving a possible alternative tool which differs from the traditional blood
diagnostic methods, and to improve investigations in hematology and artificial
bloods. Wistar rat blood samples (WRBS); SHR rat blood samples (SHRBS) and
human blood samples (HBS) were analyzed. TG curves showed two decomposition
stages for HBS at around 100 and 230C (Tonset),
while three mass degradation stages for WRBS (70, 110, 270C) and SHRBS
(70, 120, 270C) could be observed. DSC peaks showed five endotherms for
HBS at 65, 82, 194, 201 and 309C and three endotherms for WRBS at 83,
184 and 313C.
Authors:G. Schuster, G. Braun, K. Henkel, and G. Querner
The variations in the thermoanalytical curves for three differently produced powders of hydrous zirconia are discussed in connection with X-ray measurements and powdermetallurgical characterization. They were shown to characterize the ZrO2-H2O bonding and the thermal treatment for the calcination of hydrous zirconia. They allowed selection of the product with the most favourable microstructure for a high sinter activity, an explanation of the phase formation and phase transformations, and estimations of the energy content of the amorphous material and the thermal stability of the tetragonal phase. It was shown that thermal analysis is an appropriate method for the optimizing of ZrO2-powder production.
Authors:J. Kristóf, R. Frost, E. Horváth, L. Kocsis, and J. Inczédy
The thermal behaviour of ordered kaolinites from Hungary and Australia intercalated with potassium acetate, cesium acetate
and urea has been investigated by simultaneous TG-DTG-DTA, TG-MS, Raman microscopy and XRD. Remarkable changes in the thermal
decomposition pattern of the intercalates were obtained as a function of the nature of the intercalating re-agents. Replacing
the potassium cation to cesium leads to a change in the OH environments resulting in a more complicated dehydroxylation pattern.
The urea intercalates can be decomposed completely without dehydroxylating the mineral, although further treatments are necessary
to restore the original d-spacing.
NH4Y and NH4LaY-type zeolite catalysts were prepared by cyclic ion-exchange of a synthetic Linde Y-zeolite. The release of ammonia and water were followed by evolved gas analysis (automatic thermogastitrimetric equipment) as well as with a continuous selective water detector.
The influences of inactive, flowing atmospheres (noble gases, nitrogen, carbon dioxide, synthetic air) and vacuum (10−2 and 10−5 torr) on the thermal decompositions of inorganic and organic substances are discussed on the basis of literature and experimental data.