Thermogravimetry - Differential Thermal Analysis

Since TG and DTA complement each other, it is an obvious move to attempt both investigations simultaneously [173]. TG-DTA measures mass and energy changes as a function of temperature or time. Depending on the atmospheric conditions (vacuum, inert or air conditions) thermal or oxidative stability is measured. Typical TG-DTA 

Reproduced with permission from J. Janoschek, E. Kaisersberger and E. Post, Polymer Materials Science Engineering, 1993, 69, 458. Copyright 1993, the American Chemical 

A TG-DTA study of the thermochemical processes occurring at vulcanisation temperatures with N-oxydiethylene-2-benzthiazyl sulphenamide and N-cyclohexyl-2-benzthiazyl sulphenamide and their mixtures with sulphur showed the formation of high molecular weight polysulphides [73]. The influence of metallic oxides (Fe203, Sn02) on hot air ageing of one-pack room temperature vulcanised fluorosilicone rubber has been studied by means of TG-DTA [74, 75]. TG-DTA and TG were both applied to study the thermal characteristics of room temperature vulcanised silicone rubber [76]. 

TG-DTA and DSC are suitable for product quality control as exemplified by OIT measurements for polyethylene (PE) and quantitative analysis of the rubber phase in ABS and of a polymer/ softener/soot/mineral filler mixture [77]. 

Yang and co-workers [82] have reported a mechanistic study carried out based on the simultaneous measurement of enthalpy and weight loss by TG-DTA on tyre rubbers NR, SBR and BR. The hyphenated technique allows to attribute the observed exothermic peak to chemical reactions and the endothermic peak to evaporation of pyrolysis products. 

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TGA/DTA combined thermogravimetry / differential thermal analysis WDX wavelength-dispersive X-ray diffraction... 

In addition to routinely used methods, such as elemental analysis, IR and UV-vis-NIR spectra, thermogravimetry-differential thermal analysis (TG-DTA), single-crystal X-ray diffraction, and gas adsorption, there are some important characterization methods for coordination polymers. 

Thermogravimetry - Differential Thermal Analysis - Mass Spectrometry... 

The synthesis of the complex is followed by the most important step of characterization of the complex. The composition and the structural features of both the ligand and complex have to be established before embarking on further studies. There exist many methods by which the composition and structural features of the complexes are studied. Some of the methods are (i) elemental analysis, (ii) X-ray crystallography, (iii) UV-Vis absorption spectra, (iv) infrared spectroscopy, (v) Raman spectroscopy, (vi) thermal methods of analysis such as thermogravimetry, differential thermal analysis, (vii) nuclear magnetic resonance spectroscopy (proton, multinuclear), (viii) electrospray mass spectrometry. Depending upon the complexity of the system, some or all the methods are used in the studies of complexes. 

The addition of various salts to potato starch on its compression up to 1.2 X 109 Pa had only a small effect on the thermal properties of starch, as measured by thermogravimetry/differential thermogravimetry/differential thermal analysis (TG/DTG/DTA). Only FeCl3, CoCl2, and I2 caused significant effects.62... 

Analytical pyrolysis is considered somehow apart from the other thermoanalytical techniques such as thermometry, calorimetry, thermogravimetry, differential thermal analysis, etc. In contrast to analytical pyrolysis, thermoanalytical techniques are not usually concerned with the chemical nature of the reaction products during heating. Certainly, some overlap exists between analytical pyrolysis and other thermoanalytical techniques. The study of the kinetics of the pyrolysis process, for example, was found to provide useful information about the samples and it is part of a series of pyrolytic studies (e.g. [6-8]). Also, during thermoanalytical measurements, analysis of the decomposition products can be done. This does not transform that particular thermoanalysis into analytical pyrolysis (e.g. [9]). A typical example is the analysis of the gases evolved during a chemical reaction as a function of temperature, known as EGA (evolved gas analysis). 

Although the principal thermal analysis techniques are thermogravimetry, differential thermal analysis, and differential scanning calorimetry (see Chapter 1), there are a number of other thermal techniques, besides those discussed elsewhere in this book, that are useful for solving chemical and technological problems. Some of these methods are of recent development and hence little used at the present time, but they possess the potential for wider use in the future. Many of these techniques are employed to supplement or complement the three principal techniques of TG. DTA. and DSC, either in the simultaneous (single sample) or concurrent multiple samples) modes. 

Pulse thermal analysis extends the versatility of conventional thermoanalytical methods by providing a means for studying differential reaction progresses. This advantage is combined with all the opportunities of thermogravimetry, differential thermal analysis or differential scanning calorimetry and evolved gas analysis. The primary benefits of the new method are ... 

A few years later, Zhao et al. also studied the thermal stability and chemical structure of SEI formed on a natural graphite electrode in LiPFg EC/DMC electrolyte by thermogravimetry-differential thermal analysis combined with mass... 

Recently, we have studied the states of ethylbenzoate (EB) and TiCh in the primary type of MgC -supported catalyst by thermogravimetry/ differential thermal analysis (TG-DTA) in combination with other methods, and found that TiCU and EB in the MgCh-supported catalyst interact only with MgCh, leaving no vacant sites on TiCU. ... 

Z. Zheng and Q. Gao, Decomprosition of NH3BH3 at sub-ambient pressures A combined thermogravimetry-differential thermal analysis-mass sp>ectrometry study, /. Power Sources 196, 2011,1615-1618. 

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