Simultaneous thermal analysis

The design of these systems are generally comprised of a post with sample and reference cups at the top, while the base fits into a sensitive analytical balance (e.g. Harrop, Mettler, and Netzsch) or, the sample and reference cups at the bottom, with the post suspended from a balance arm from above 

Since the kinetic energy of a particle set in motion by cath- 

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Continuous monitoring of the carbon monoxide and carbon dioxide evolved during thermal decomposition of brominated polyester resin samples, has been carried out using a simultaneous thermal analysis-mass spectrometry technique. In order to allow measurement of the carbon monoxide evolved, the atmosphere chosen for these runs was 21% oxygen in argon, since the peak at 28 atomic mass units (amu)... 

Simultaneous Thermal Analysis (STA) A technique which combines DTA, TGA, DSC (cal.) and derivatives of DTA/TGA in a single instrument, offers advantages over the performance of each technique as a separate experiment on stand-alone instruments. By examining a single sample, one ensures no variation in sample homogeneity, atmosphere difference and other instrumental parameters. At the same time, there is a provision for detection and analysis of evolved gases (EGA) during thermal decomposition. Also, derivatives of TGA and DTA can be precisely measured (electronically). 

Lopez-Capel, E., Bol, R., and Manning, D. A. C. (2005a). Application of simultaneous thermal analysis mass spectrometry and stable carbon isotope analysis in a carbon sequestration study. Rapid Comm. Mass. Spect. 19, 3192-3198. 

The TG-DSC technique has recently been reviewed [56]. Redfern [57] has reviewed single sample simultaneous thermal analysis, i.e., TG-DSC and TG-DTA studies of polymers. 

Whereas Redfern [57] has pointed out the advantages of simultaneous thermal analysis techniques (particularly TG-DSC and TG-DTA) over techniques conducted singly, an even more complete thermal profile is provided when a thermal analyser is coupled to some form of gas analyser (MS or FTIR). Mohler and co-workers [51] have reported TG-DSC-MS of the thermal decomposition of the vulcanisation accelerator tetramethyl thiuram disulphide (TMTD) in rubber degradation of TMTD starts at about 155 °C, as evidenced by m/z 76 (CS2) and 44 (radical of the secondary dimethylamine). 

A popular and useful device is a combined DTA/TG (simultaneous thermal analysis STA) system in which both thermal and mass change effects are measured concurrently on the same sample. An example STA study comprising DTA, TG, and DTG for the decomposition of calcium oxalate is shown in Figure 5.7. 

Small particle sizes of raw batch materials accelerate melting and homogenization via an increase in the reaction area between raw materials. However, the use of very fine raw materials has an associated dusting problem along with the added cost of particle size reduction. In the following, simultaneous thermal analysis in conjunction with x-ray diffraction were used to determine the fusion path in a typical glass composition as a function of particle size. 

The experiments were carried out in a Netzsch STA 409 C (Simultaneous Thermal Analysis - STA) in the TGA/DSC configuration. The STA has a vertical san le carrier with a reference and a sample crucible, and in order to account for buoyancy effects, a correction curve with empty crucibles was first conducted and then subtracted from the actual experiments. Platinum/Rhodium crucibles were used in order to get the best possible heat transfer. The thermocouple for each crucible was positioned Just below and in contact with the crucible. The ten rerature obtained from the measurement is the temperature in the reference side. This temperature is converted to the temperature in the sample side by using the DSC-signal in pV and a temperature-voltage table for the thermocouple. The product gases were swept away by lOO Nml/inin nitrogen which exited the top of the STA, The STA was calibrated for temperature and sensitivity (DSC) with metal standards at each heating rate. 

Warrington, S.B. Simultaneous thermal analysis techniques. In Principles of Thermal Analysis and Calorimetry Haines, P.J., Ed. Royal Society of Chemistry Cambridge, U.K., 2002 Chapter 6, 172-174. 

The TG-DSC curves were measured on a Netzsch 409 EP Simultaneous Thermal Analysis device, using 20 mg of powdered sample. To analyse the effect of heat treatment of the samples, the experiments were carried out heating in air at a rate of 5 °C min, from ambient to lOOOT, using a-alumina as a reference. 

Coupled or simultaneous thermal analysis techniques are gaining more and more importance for several reasons ... 

This chapter is concerned with the large family of Simultaneous Thermal Analysis (STA) techniques, in which two or more types of measurement are made at the same time on a single sample. This methodology, entailing a more complex instrument, often specially built, has been found to be essential in a variety of thermal studies, and instruments for simultaneous measurements have been constructed for more than fifty years - often as soon as it was technically possible, as the benefits of this approach were rapidly appreciated. 

Simultaneous Thermal Analysis (STA) and Mass Spectrometry Systems) The Fine Work Co. Ltd... 

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