Thermogravimetric analysis interpretations

Thermogravimetric analysis (TGA) measures cellulose pyrolytic mass loss rates and activation parameters. The technique is relatively simple, straightforward and fast, but it does have disadvantages. One disadvantage is that determination of the kinetic rate constants from TGA data is dependent on the interpretation/analysis technique used. Another disadvantage of TGA is that the rate of mass loss is probably not equivalent to the cellulose pyrolysis rate. 

R.W. Mickelson I.N. Einhom, "Kinetic Interpretation in Thermogravimetric Analysis , Combustn Flame 28 (1) (1977),45-61... 

Thermoanalytical investigations of sedimented airborne particulates [EINAX and LUDWIG, 1991] confirm experimentally the chemometrically found interpretation that aluminum can serve as an indicator element for lignite combustion. Thermogravimetric analysis of mixed samples of sedimented dusts detect a loss of mass at a temperature of 714°C this can be interpreted as dehydration of aluminosilicates. This loss of mass exhibits a well defined summer minimum and a strong winter maximum. These findings also correspond to the results from factor analysis (see Section 7.2.1.2.4). 

Further heating of the sample to I (250°C) produces no further interpretable thermal response. And since another test, thermogravimetric analysis (TGA), which I will not discuss in this chapter, shows that the polymer sample loses a little weight (suggestive of decomposition) at approximately 250 °C, we heat the sample no further but now immediately begin to cool it at 10°C/min. 

Thermogravimetrical analysis provides information on loss of mass which may be a result of degradation with volatilization of plasticizer component, plasticizer evaporation, or degradation and volatilization of any other component of the tested mixture (most likely polymer and stabilizer because test formulations are usually kept simple). Beeause of these different reasons for mass loss the results are difficult to interpret. In some studies reported here, evaporation loss of plasticizer was distinguished from loss of degradation products by ranning two separate tests one for the pure plasticizer and the other for the entire composition. This may help to better understand reasons for mass loss but it... 

BH2 NH2-)n oligomers with n>5 have been studied by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) [30], as well as by mass spectrometry and X-ray photoelectron spectrometry. The results have been interpreted in terms of a large cyclic structure of poly(aminoborane) [31]. 

Once the aggregate nature and the occurrence of other carbonate materials are estabhshed, the binder carbonates are separated by a combined mechanical and physical procedure (Ortega et al., 2008). This method removes the carbonate fraction, lime lumps and the charcoal particles. The extraction procedure allows to obtain binder reliable for dating without using partial acid digestion and several radiocarbon measurements of complex interpretation. In order to test the effectiveness of mechanical separation and to verify the purity of the binder. Scanning Electron Microscope (SEM), X-ray diffraction (XRD) analyses and thermogravimetric analysis (TGA) were performed. To test the developed procedure, historic lime mortars from the parish church of Santa Maria la Real (Zarautz, northern Spain) have been dated. 

Spectral analysis of volatile products shows that pure plasticizer evaporates before thermal degradation of PVC is recorded.Kinetic models of PVC thermal decomposition for interpretation of thermogravimetric data were proposed and verified by experimental data. ... 

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