Thermogravimetry derivative

The thermal behavior of the hyperbranched polymer 7, as well as that of the related tetra- and octanuclear dendrimers 1 and 2, was examined by thermal gravimetric analysis (TGA) and derivative thermogravimetry (DTG). The samples were heated at a ramp rate of 10 °Cymin under nitrogen atmosphere in the tenqierature range 25-8(K) °C. The major decompositions occur between 340 and 540 °C for the tetranuclear 1, and between 370 and 520 °C for the octanuclear 2, whereas for polymer 7 a faster rate of weight loss is observed at a higher (480 and 560 C) temperature range. The thermal stability of the network dendrimeric material 7 is... 

Fig. 7.6 Derivative thermogravimetry (DTG) under N2 flow of C60H36 showing a maximum decomposition rate at 501°C. The perdeuterated C6ffD3(j shows a decomposition at much higher temperature 549°C. This temperature difference in the decomposition has been interpreted in terms of isotope effect due to deuteration...

Heal, G.R. Thermogravimetry and derivative thermogravimetry. In Principles of Thermal... 

Heal G.R. Thermogravimetry and derivative thermogravimetry. In Principles of Thermal Analysis and Calorimetry Haines, P.J., Ed. Royal Society of Chemistry Cambridge, U.K., 2002 Chapter 2, 51-53. 

Generic RTV Silicones. Our major purpose in the study of the RtV silicone by TGA is to optimize the thermal stability of the formulation. The TGA curve reveals not only the thermal stability of RTV silicone material but also the degree of dispersion of polymer-filler and/or filler-filler incorporation. With the aid of derivative thermogravimetry (DTG) curve we are able to detect any decomposition of the polymer. A wel 1-dispersed filler-filled silicone material will result in one distinct derivative TGA curve (see Figure 8). However, poor dispersion of the polymer and flller(s) or poor polymer resin often reveals more than one derivative from the DTG curve. The phase separation between polymer-filler and/or filler-filler may be the cause of the multiple DTG cure. Even very close decompositions peaks which are hard to distinguish from the TGA curve will also be easily distinguished by the derivative curve. 

Figure 8 First Derivative Thermogravimetry Spectra of a Silicone...

A computer carries out all the manipulations, calculations and plotting of TG graphs required. It also calculates the derivative thermogravimetry (DTG) curve if required. 

Quantitative measurements of the mass-changes are possible by determination of the distance, on the curve mass axis, between the two points of interest or between the two horizontal mass levels. In derivative thermogravimetry, the derivative of the mass-change with respect to time, dm/dt, is recorded as a function of time (r) or temperature (T). or... 

The advantages of derivative thermogravimetry have been summarized by Erdey et al. (61) ... 

The curves for DTA and derivative thermogravimetry (DTG) are comparable, but the results of the former method indicate even those changes of state that are not accompanied by loss in mass. The curves by the latter method are more reproducible. 

If derivative thermogravimetry is employed, the method of obtaining the derivative should be indicated and the units of the ordinate specified. 

Derivative Thermogravimetry (DTG). A technique yielding the first derivative of the thermogravimetric curve with respect to either time or temperature. 

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