Thermogravimetric and differential thermal analysis

Ramiah, M.V. (1970). Thermogravimetric and differential thermal analysis of cellulose, hemicellulose, undLligmn. Journal of Applied Polymer Science, 14(5), 1323-1337. 

Russian workers have continued to study hydrated salts of lanthanide ions. Some of these studies are of a rather detailed nature and a summary of some of the more recent work will be given here to indicate its general nature. There is considerable emphasis on phase studies, X-ray powder data, thermogravimetric and differential thermal analysis, and IR data. 

Thermal Stability. The thermal behavior of the complexes was determined two ways. The first was thermogravimetric and differential thermal analysis. The second was to keep the polychelates in a furnace at up to 1000°C in air. 

Fig. 5.3 Thermogravimetric and differential thermal analysis curves for reacted C3S paste experimental conditions as for Fig. 5.2. After Taylor and (T14).

Cr and Ce compounds reduce the temperature of initiation of the thermooxidative decomposition of the same polymer by 80-100 °C, but the rate of the decomposition itself is lower than that of the unmodified polymer. Thermogravimetric and differential thermal analysis have shown that Me " have no influence on the thermal decomposition of the polymer in the absence of an oxidative atmosphere. 

Figure 9.9 Thermogravimetric and differential thermal analysis (TCA-DTA) of the three phases of AIH3 a-phase (solid line), p-phase (dotted line) and y-phase (dashed line) Ref [23].

The fact that flame retardants and salts alter the kinetics, as well as the products, of the pyrolysis reactions is confirmed by the investigations of Tang and Neil involving thermogravimetric and differential thermal analysis methods (see Section 11,6 p. 446). These investi-... 

Thermogravimetric and Differential Thermal Analysis has been performed on Cat D. The TG and DTA profiles in Fig 2 show three different steps. The first one is the evaporation of hydrocarbons up to 200 °C with a moderate endotherm. The second step is the oxidation reaction of metal sulfides to oxides (most of the Mo sulfide, and part of the Co sulfide), starting around 200-250 °C. The third step around 350-450 °C is strongly exothermic, due to carbon burn-off as well as the remaining of sulfides oxidation. The carbon bum-off reaction finishes around 500 °C in this experiment performed on a dynamic mode at the heating-up rate of 5 °C/min. 

Figure 2. Thermogravimetric and Differential Thermal Analysis of Cat D under mr flow and a heating rate of 5 °C/min.

Simultaneous thermogravimetric and differential thermal analysis (TG/DTA) is a useful technique for the solid-state characterization of pharmaceutical materials. Such characterization includes the determinations of loss on drying, phase transition temperatures, thermal stability, and whether or not water is bound or unbound. TG/DTA combines the measurement of a change in mass of a sample as a function of temperature (TG) with the temperature difference of a sample compared with an inert reference material as a function of temperature (DTA). 

FIGURE 6 Thermogravimetric and differential thermal analysis results from a granulation blend of a hydrated API. The thermogravimetric curve is dotted the differential thermal analysis curve is solid the derivative of the thermogravimetric curve is dashed. 

X-ray diffraction patterns were recorded on a Siemens D5000 diffractometer using CuKa radiation. Thermogravimetric and differential thermal analysis curves were recorded on a Setaram Setsys 12 thermal analysis station by heating in an argon atmosphere from 25 to 1200 -C at a rate of 5 min". Samples were used untreated. The Pt content was determined by the Service Central d Analyse, CNRS (Vernaison, France) and the microanalyses (C, H) were performed at Complutense University (Madrid, Spain). Na isotherms were determined on a Micromeritics ASAP 2000 analyzer. H MAS NMR, Si MAS NMR and C CP MAS NMR spectra were recorded at 400.13, 79.49 and 100.61 MHz, respectively, on a Broker ACP-400 spectrometer at room temperature. An overall 1000 free induction decays were accumulated. The excitation pulse and recycle time for H MAS NMR spectra were 5 ps and 3 s, respectively, those for Si MAS NMR spectra 6 ps and 60 s and those for C CP MAS NMR spectra 6 ps and 2 s. Chemical shifts were measured relative to a tetramethylsilane standard. Prior to measurement, if necessary, samples were dehydrated in a stove at 423 K for 24 h. 

In addition, there are some other characterization techniques that can be used to examine the carbon-Ti02 composites, including Raman spectroscopy [40,123], atomic force microscopy (AFM) [106,123], thermogravimetric and differential thermal analysis (TGA-DTA) [26,125], determination of pHpzc [19,29], and electron paramagnetic resonance (EPR) [126,127],... 

The Qualitative determination of major crystalline phases was achieved using the Philips X Pert Pro automated diffractometer equipped with a Ge (111) primary monochromator. Chemical composition was determined by X-ray fluorescence (XRF) using the Philips Magix Pro (PW-2440). Thermal behaviour was determined by thermogravimetric and differential thermal analysis (TGA-DTA) with a Mettler Toledo 85 le device in oxygen operating at a ramp of 20 °C/min from room temperature to 1000 °C. 

FIGURE 22 Thermogravimetric and differential thermal analysis profiles for Ca(CH3C00)2-H20. 

Thermogravimetric and differential thermal analysis were also performed in a TA SDT 2%0 TG-DSC simultaneous instrument. Pt crucibles containing 5-7 mg of sample were heated at 2°C/min from room temperature to 1000 °C under dry oxidizing atmosphere. In order to verify the effectiveness of the separation method, several fractions during extraction process have been analyzed by above described techniques. 

---