Polymers thermogravimetric analysis sample

This phenomenon can be demonstrated by both measuring the changes of the thermal properties of the ECA homopolymer and in adhesion tests. The addition of only 1 wt.% of 9 to a sample of the ECA homopolymer significantly increases the onset of decomposition in the thermogravimetric analysis (TGA) of the polymer, as seen in Fig. 9 [29]. 

The modified NBR samples were characterized by differential scanning calorimetry [11,78-80,98]. The glass-transition temperature (T ) decreased with the level of hydrogenation. In the case of HFNBR, Tg increased with an increase in the addition of aldehyde groups to the polymer chain. Thermogravimetric analysis of the modified polymers have also been carried out [15]. 

Both thermogravimetric analysis and differential scanning calorimetric studies were carried out on modified and unmodified PPO samples. Table IV presents the weight losses and the glass transition temperatures of the most representative polymers. 

Thermogravimetric analysis In thermogravimetric analysis (TGA) a sensitive balance is used to follow the weight change of the sample as a function of temperature. Its applications include the assessment of thermal stability and decomposition temperature, extent of cure in condensation polymers, composition and some information on sequence distribution in copolymers, and composition of filled polymers, among many others. 

A second analytical technique for polymer blends involves the use of thermogravimetric analysis as seen in figure 18. Here again the percent polyester is determined in the presence of cellulosics. Such an analysis should have about the same accuracy for submicrogram samples as DSC (12). 

The [Cr(H20)(0H) 0P(C H8)20 2]a polymer is a green solid which is readily soluble in chloroform, benzene, and tetrahydro-furan but is insoluble in water and diethyl ether. It does not melt before decomposing thermogravimetric analysis indicates decomposition starting at 365°C. A freshly prepared solution in chloroform has an intrinsic viscosity ranging from 0.03 to 0.04 dl./g. The intrinsic viscosity increases slowly when solutions in organic solvents (for example, 1 g./lOO ml. in chloroform) are allowed to stand at temperatures of approximately 55°C., and values of 0.6-0.8 dl./g. are common after a number of days. A sample with an intrinsic viscosity of 0.04 dl./g. 

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. 

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. 

Thermogravimetry (TG) or thermogravimetric analysis (TGA). In this technique, the mass of a sample is followed as a function of temperature or time. The amount and rate of mass change with temperature or time in a controlled atmosphere are obtained. Such information can tell us about thermal stability as well as the compositional profile of a variety of elastomers and polymers. It is an excellent quantitative technique but qualitatively there may be some doubt as to what material is lost during heating. 

The polymer has a crosslinked structure, and the curve showing the variation of weight loss % as a function of temperature (thermogravimetric analysis or TGA curve) is given in Figure 3.1.2. The sample was heated in N2 between 30° C and 830° C at a heating rate of 10° C/min. 

Investigation of the kinetic of mass loss at thermooxidative destruction of modified CDA showed that modification increases its stability to the heating at elevated temperatures (Figure 2.33). Loss of mass of modified CDA in much less in comparison with initial values during prolonged heating of polymer samples in the air (150°-200°C). These conclusions are proved by the results of complex thermogravimetric analysis (TGA). 

Thermogravimetric analysis was used to follow the curing of polymer films. This technique is predicated on the volatility of the unreacted components. In the present study the volatile components have been determined to be EEA, HDODA, TMPTA, Irgacure 651, and their volatile reaction products. The Epocryl 370 resin and the VTBN rubber were found not to contribute to the volatiles. Decomposition of the mixtures generally took place about 310-350°C in all cases, including the rubber modified samples. 

Isothermal methods have generally been used for the study of thermal degradation mechanisms and the determination of kinetic parameters. In recent years, however, dynamic thermogravimetric analysis (TGA) has been developed. In this case, polymer samples are weighed in a... 

For the last twenty years much work has been done in the study of the thermal stability of lignocellulosic materials by thermal analytical methods. Since these materials are complex mixtures of organic polymers, thermogravimetric (TG) analysis causes a variety of chemical and physical changes depending on the nature of the sample and its treatment prior to analysis. These problems have been reviewed recently. ... 

Characterization of Polymers. The characterization of polymers Ifi - 21 was mainly spectroscopic in nature, FTIR and NMR, but some thermal analyses were also performed. The thermal analyses consisted of differential scanning calorimetry, DSC, and thermogravimetric analysis, TGA. Although the thermal analyses were in no way exhaustive, a few interesting features were found in the different polymers. The molecular weights of samples were examined by GPC and are based on polystyrene standards. 

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