Thermogravimetric analysis traces

Figure 2.31 Thermogravimetric analysis traces of mercaptopropanesulfonic acid...

Fig. 4.21. Thermogravimetric analysis of a compound capable of being isolated as an anhydrate crystal form (solid trace), and as the monohydrate (dashed trace) and dihydrate (dotted trace) solvatomorphs.

Figure 15. A typical thermogravimetric analysis (TGA) trace of a polymer resist that has been spin-coated and NOT prebaked. The small weight loss at low temperature is due to solvent evaporation and the high temperature weight loss is due to thermal decomposition.

Thermogravimetric Analysis. PMMA prepared by initiation with low concentrations of sulfur dioxide at or near room temperature has been found to incorporate from negligible amounts to trace quantities of SOu at chain ends and/or at any other part of the chain presumably by copolymerization (15). Thermogravimetric analysis of a few PMMA samples prepared in the presence of SOu under varied conditions has... 

The preparation of boron nitride from orthoboric acid and urea is described by T. E. O Connor [81]. Special measures are required to remove the last traces of boric oxide commercial preparations are likely to be significantly contaminated with 820 and water. Deacon and Goodman [11] found a small loss of volatiles at 373-423 K from boron nitride subjected to thermogravimetric analysis in air and a large increase in weight at 1123-1173 K, which is the temperature range of the active oxidation of BN to B2O2. 

Frequendy, it is not easy to determine the temperatures Ti,T2,..., owing to the nearly horizontal nature of the curve in those regions and the attendant indistinct beginning and ending temperatures of the reaction steps. This means also that it is not easy to determine accurately the mass loss in such cases. Because of this, some instruments also compute the trace of the first derivative of the mass curve simultaneously. This DTG (derivative thermogravimetric analysis) makes it much easier to determine where a zero slope indicates that the sample is undergoing no change in mass. Therefore, the reaction stoichiometry can be more accurately determined. 

Thermogravimetric analysis (25-100°) shows a <0.05% weight loss, indicating that Tl4(C03)[Pt(CN)4] is anhydrous. Emission spectrographic analysis indicates the product to be of high purity it contains the metals Tl and Pt and impurities as follows faint traces of Ca and Li (<0.001%). Iodine-thiosulfate titration studies are negative, indicating no partial oxidation of Pt therefore, Pt is present as Pt °. 

The copolymers were thermogravimetrically studied with the help of Seteram Co. thermoweighing machine B-60 in argon (at the heating rate of 5 deg/min) with simultaneous selection and analysis of gaseous degradation products, and the effect of introduction of bulky cyclic fragments into the back-bone on their thermal stability was traced. 

The thermogravimetric analyses (TGA) of microcrystalline powders of this complex trace revealed two discrete mass losses at 110 °C and 145 °C corresponding to a mass percent of four (4.5%) and twelve benzene molecules (13.5%) respectively. It was rationalized that the initial mass loss corresponded to the loss of four disordered benzene units. The mass loss at 145 °C was attributed to the loss of the ordered twelve benzenes. Differential scanning calorimetry (DSC), optical microscopy and X-ray powder analysis showed that there was no phase change associated with the first mass loss. 

A systematic study of the influence of sample preparation on the differential thermal analysis and thermogravimetric behaviour was then undertaken. The results were shown to be very sensitive to the method of polymerization and residual traces of catalyst. Initiation of cyclization at... 

Thermogravimetric (TGA) analysis was run to investigate the thermal behavior of resulted nanocomposite. The derivative traces were analyzed for each constituent in order to determine the decomposition temperatxire, while weight traces were used to determine the weight loss associated with the decomposition of this constituent (ASTM E 1131). In addition, the ash content was computed from the final weight. Table 13.3 shows TGA traces for neat CAB, whiskers-filled CAB nanocomposite and kenaf whiskers from previous study. 

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