Thermogravimetry - Differential Thermal Analysis - Mass Spectrometry

6 Thermogravimetry - Differential Thermal Analysis - Mass Spectrometry 

TG/DTG-DTA-MS equipment has been available since 1979 [11]. As mentioned before, simultaneous TG-DTA-MS was used to investigate the exothermic reactions that take place at approximately 300 °C between Alloprene binder and NaN03 and Sr(N03)2 in various pyrotechnic compositions, including the effect of titanium [85]. For both binary nitrate - Alloprene mixtures, reaction is initiated by Alloprene decomposition another characteristic reaction is that of HC1 (from the chlorinated rubber decomposition) with the nitrate to yield the metal chloride. 

Manley [32] examined a cured phenolic formaldehyde (PF) resin by means of TG-DTA-MS observing a lower sensitivity of TG relative to DTA. However, new TGA instrumental developments have been reported since. The TG curve shows loss of phenol (MS evidence m/z 94) DTA observes water (MS m/z 18), ammonia (MS m/z 17) and formaldehyde 

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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. 

Leinweber P, Schulten HR. Differential thermal analysis, thermogravimetry and in-source pyrolysis-mass spectrometry studies on the formation of soil organic matter. Thermochim. Acta 1992 200 151-167. 

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. 

Mara. Kamei and Osada [109 described a detailed study of the thermal decomposition of TNT. They examined the decomposition by differential thermal analysis, thermogravimetry, infra-red spectroscopy. HSR and mass spectrometry. One of their most important findings was that TNT produced free radicals already in the vicinity of the melting point, that is SO C. The substances which promote the decomposition of TNT are free radicals which are stable at room temperature. They are insoluble in benzene or chloroform and are partly oxidized polymeric substances. 

Applying conventional (thermogravimetry TG Differential thermal analysis DTA evolved gas detection EGD) and combined (thermogravimetry-mass spectrometry TG-MS) techniques, the pCD inclusion complexes with thymol and Lippia sidoides Cham EO (LsCEO) extract produced by kneading method were characterized. Its formations were detected through released gas... 

Although water is known as a natural plasticizer for many polar polymers such as nylon, polyester resins, and cellulosic polymers, similar behavior for polyacrylamide and poly(acrylamide-co-acrylic acid) has not been investigated. In this study, the effect of water content (and/or thermal history) on the Tg s of acrylamide-based pol3 TOers was studied by Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Thermomechanical Analysis (TMA), and Simultaneous Thermogravimetry - Mass Spectrometry (TG/MS). 

Two thermal methods have been extensively studied in recent years, pyrolysis-gas chromatography (Py-GC) - mass spectrometry (MS) and evolved gas analysis involving infrared spectroscopy (IR) - MS, thermogravimetry and differential scanning calorimetry (DSC). 

Reports on the detailed thermal behaviour of PEEK/HAp composites [as well as other polymer/HAp (nano)composites] are scarce in the literature. Advanced thermal analysis methods, e.g., modulated temperature differential scanning calorimetry (MTDSC) or hyphenated thermoanalytical methods such as thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) or mass spectrometry... 

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