Differential thermal analysis applications

W. Smykatz-Kloss, Differential Thermal Analysis, Application and Results in Minerology, Springer-Verlag, NY (1974). 

Smykatz-Kloss, W. Differential Thermal Analysis Application and Results in Mineralogy Springer-Verlag New York, 1974 185 pp. 

Werner, S. K., Differential Thermal Analysis Applications and Results in Mineralogy. Berlin, Springer, 1974. 

Mackenzie, R. C., (ed.), Differential Thermal Analysis Applications, 2 607 Academic Press, New York (1972)... 

The techniques referred to above (Sects. 1—3) may be operated for a sample heated in a constant temperature environment or under conditions of programmed temperature change. Very similar equipment can often be used differences normally reside in the temperature control of the reactant cell. Non-isothermal measurements of mass loss are termed thermogravimetry (TG), absorption or evolution of heat is differential scanning calorimetry (DSC), and measurement of the temperature difference between the sample and an inert reference substance is termed differential thermal analysis (DTA). These techniques can be used singly [33,76,174] or in combination and may include provision for EGA. Applications of non-isothermal measurements have ranged from the rapid qualitative estimation of reaction temperature to the quantitative determination of kinetic parameters [175—177]. The evaluation of kinetic parameters from non-isothermal data is dealt with in detail in Chap. 3.6. 

These parameters need to be considered for reactions that go towards the intended completion as well as for possible upsets (see section C). Measuring methodologies for determining characteristic material property values (Stoffkenngrofcen), e.g., differential thermal analysis ("DTA"), calorimetry, and adiabatic experiments, and their possible use and applications are given in the literature /1, 2, 3, 41. 

The difference of temperature between the sample under estimation and a thermally-inert reference material is continuously recorded as a function of furnace temperature in differential thermal analysis (DTA). In actual practice both TGA and DTA are regarded as complementary techniques whereby information gathered by the usage of one approach is invariably supplemented and enhanced by the application of the other method. The range of phenomena measurable during a DTA-run is found to be much larger than in a TGA-run. 

Figure 6.1. High temperature Tammann type furnace and its application to differential thermal analysis. The supports A act also as connections to the electric supply (typically about 10 volts and several hundred amperes) B upper lid and electric connection to the carbon tubular resistance C the tube C is surrounded by packed granular carbon inside the ceramic insulating filling D ...

Pacor, P. Applicability of the DuPont 900 DTA apparatus in quantitative differential thermal analysis. Anal. Chim. Acta, 37 200-208, 1967. 

More advanced techniques are now available and section 4.2.1.2 described differential scanning calorimetry (DSC) and differential thermal analysis (DTA). DTA, in particular, is widely used for determination of liquidus and solidus points and an excellent case of its application is in the In-Pb system studied by Evans and Prince (1978) who used a DTA technique after Smith (1940). In this method the rate of heat transfer between specimen and furnace is maintained at a constant value and cooling curves determined during solidification. During the solidification process itself cooling rates of the order of 1.25°C min" were used. This particular paper is of great interest in that it shows a very precise determination of the liquidus, but clearly demonstrates the problems associated widi determining solidus temperatures. 

E.E. Mason, "Application of Derivative Differential Thermal Analysis to Military High Explosives . NAVWEPS Rept 6996... 

DSC and related methods (differential thermal analysis, DTA) are of great practical importance. Therefore, one finds highly sophisticated commercial instruments for a variety of applications. DTA has been combined with in-situ emf and Knudsencell measurements. The interested reader is referred to the special literature on this subject [M.E. Brown (1988)]. 

Interest in the use of calorimetry as a routine diagnostic or analysis tool has gained significant momentum only in the last 50 years. This interest has lead to the development of popular procedures such as differential thermal analysis (DTA) and differential scanning calorimetry (DSC). A wide variety of solution calorimetric techniques exist today. These techniques include thermometric titration, injection and flow emhalpimetry. The major growth of commercial instrumentation for calorimetry has occurred to address applications in routine analysis and the rapid characLerizaiion of materials. 

In some instances, an adiabatic bomb calorimeter may not be available or the sample may be too small for accurate use. To combat such problems, there is evidence that differential thermal analysis (DTA) is applicable to the determination of the calorific value of coal. Data obtained by use of the DTA method are in good agreement with those data obtained by use of the bomb calorimeter (Munoz-Guillena et al., 1992). 

Several methods have been developed over the years for the thermochemical characterisation of compounds and reactions, and the assessment of thermal safety, e.g. differential scanning calorimetry (DSC) and differential thermal analysis (DTA), as well as reaction calorimetry. Of these, reaction calorimetry is the most directly applicable to reaction characterisation and, as the heat-flow rate during a chemical reaction is proportional to the rate of conversion, it represents a differential kinetic analysis technique. Consequently, calorimetry is uniquely able to provide kinetics as well as thermodynamics information to be exploited in mechanism studies as well as process development and optimisation [21]. 

Borchardt, H.). and Daniels, F. (1975) The application of differential thermal analysis to the study of reaction kinetics, Journal of American Chemical Society, 79, 41-6. 

Jambu, R, Dupuis,T., and Garais, M. (1975a). Use of differential thermal-analysis to characterize fulvic acid metal complexes and humic acid metal complexes. 2. Application to natural organometallic complexes. J. Therm. Anal. 8(2), 231-237. 

The thermal characterisation of elastomers has recently been reviewed by Sircar [28] from which it appears that DSC followed by TG/DTG are the most popular thermal analysis techniques for elastomer applications. The TG/differential thermal gravimetry (DTG) method remains the method of choice for compositional analysis of uncured and cured elastomer compounds. Sircar s comprehensive review [28] was based on single thermal methods (TG, DSC, differential thermal analysis (DTA), thermomechanical analysis (TMA), DMA) and excluded combined (TG-DSC, TG-DTA) and simultaneous (TG-fourier transform infrared (TG-FTIR), TG-mass spectroscopy (TG-MS)) techniques. In this chapter the emphasis is on those multiple and hyphenated thermogravimetric analysis techniques which have had an impact on the characterisation of elastomers. The review is based mainly on Chemical Abstracts records corresponding to the keywords elastomers, thermogravimetry, differential scanning calorimetry, differential thermal analysis, infrared and mass spectrometry over the period 1979-1999. Table 1.1 contains the references to the various combined techniques. 

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