Thermogravimetric analysis, degradation, thermal

The thermal degradation of TsHs and other TsRs species (R = Me, /Bu, nCsHiy, Ph) in air and an inert atmosphere has been studied by thermogravimetric analysis and shows that for TsHs incomplete sublimation tends to occur, and, in air, oxidation competes with volatalization. ... 

Thermal stability is a crucial factor when polysaccharides are used as reinforcing agents because they suffer from inferior thermal properties compared to inorganic fillers. However, thermogravimetric analysis (TGA) of biocomposites suggested that the degradation temperatures of biocomposites are in close proximity with those of carbon black composites (Table-1). 

Figure 4. Thermogravimetric analysis of polymer VII (upper curve) with derivative (lower curve) showing two distinct thermal degradations.

Brack, H.-P, Ruegg, D., Biihrer, H., Slaski, M., Alkan, S. and Scherer, G. G. 2004. Differential scanning calorimetry and thermogravimetric analysis investigation of the thermal properties and degradation of some radiation-grafted films and membranes. Journal of Polymer Science Part B Polymer Physics 42 2612-2624. 

Recently, MS combinations have been available including the thermogravimetric analysis mass spectroscopy (TG-MS) combination developed by Carraher that allows the continuous characterization of evolved materials as a polymer undergoes controlled thermal degradation. 

Thermogravimetric analysis, though not necessarily indicative of all high temperature properties, is a convenient way to indicate the degree of thermal reaction occurring at a particular temperature. The thermal stability of polyimides has been the subject of many studies (10). Our results obtained from free films of 1-2 mils are shown in Fig. VII and are in agreement with Heacock and Berr(ll). Since 1-2 mil films are not used here, we decided to study the thermal degradation of... 

Kinetic data on the thermal degradation of ABS and PC/ABS blends are available (130,131). Thermogravimetric analysis suggests that the kinetics of the thermal degradation can be modelled by an auto-catalytic process. 

Thermal analysis is a group of techniques in which a physical property of a substance is measured as a function of temperature when the sample is subjected to a controlled temperature program. Single techniques, such as thermogravimetry (TG), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), dielectric thermal analysis, etc., provide important information on the thermal behaviour of materials. However, for polymer characterisation, for instance in case of degradation, further analysis is required, particularly because all of the techniques listed above mainly describe materials only from a physical point of view. A hyphenated thermal analyser is a powerful tool to yield the much-needed additional chemical information. In this paper we will concentrate on simultaneous thermogravimetric techniques. 

Thermogravimetric analysis (TGA) is widely used to study the thermal stability of a polymer and to evaluate the effect of adding filler particles on the thermal degradation of the elastomers. 

It is known [1], that the intensive thermal degradation temperature Td characterizes the polymer s thermostability. As the characteristic of thermostability according to [2] limiting temperature is accepted at which chemical change of polymer reflected on its properties takes place. The thermostability is determined with the aid of thermogravimetric analysis (TGA). Hereafter under Td a sample of 5%-th mass loss temperature obtained in TGA testing will be understand. 

Thermogravimetric analysis of the copolymers has displayed 5% mass loss at 330-360°C. Basic degradation process proceeds in the temperature range of 420 - 550°C, and above 620°C mass chan-ge curves become supersaturated. Thermal oxidative stability of... 

Thermogravimetric analysis has indicated mass losses of copolymers at 260 - 270°C not exceeding 2 - 3%. At 300 - 350°C thermal degradation rate is considerably increased, and at 550°C mass losses are maximal. The mass loss is regularly increased with the length of dimethylsiloxane backbone, i.e. at transition from dimethylsiloxane to disiloxane bridge. 

For applications requiring high temperature and extraction resistance, polymeric esters are used (88). New polymeric plasticisers are in development (87) including adipate based for improved low temperature properties (103). Plastisols based on propyleneglycol adipate have been examined (198) and the thermal degradation has been determined using dynamic and isothermal thermogravimetric analysis (188). 

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