Thermogravimetry polymer stability

Each sample was evaluated by thermogravimetry to determine if the thermal stability could be enhanced by removing some residual cobalt chloride. The BTDA-ODA polyimide film thermal stability is reduced about 50 C due to the cobalt chloride dopant. Soa)cing or extraction with water has no positive effect on the thermal stability whereas soxhlett extraction with DMAc severely degrades the polymer stability. For the BDSDA-ODA polyimide films the incorporation of cobalt chloride also reduces the bul)c polymer thermal stability. Soa)cing this film in water for 24 hours, however, increased the bul)c thermal stability slightly from 512 to 532 C. 

Numerical evaluation of non-isothermal thermogravimetry is of interest as the polymer ignition is usually related to it. Activation energy withdrawn from single thermogravimetry run represents the scale of the polymer stability as well as its ignitability. 

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... 

In the present study, PU s containing lignin were investigated with reference to thermal stability, which is one of the basic thermal properties of polymers. Thermal degradation of PU s which were obtained from solvolysis lignin was studied using thermogravimetry (TG). The inflammability of... 

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 stability of the polyyne-type polymers can be examined by thermogravimetry and differential thermal analysis (TG/DTA). From the DTA curves in Figure 10.5, an exothermic peak is observed in all cases. The very broad peak for PpPE is observed around at 350°C, while the sharp peak is observed at 207°C for PpPB and at 138 C for PpPO, respectively. The exothermic peak temperature should be related with thermal stability of the polyyne-type polymers, thus it is concluded that the most stable is PpPE... 

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. 

The relative thermal stabilities obtained by dynamic thermogravimetry above 200°C and by isothermal methods at 220°C are given in Figs. 51 and 52. (A) is a slightly branched polymer sample produced using benzoyl peroxide. Polymer (B) is a linear syndiotactic sample prepared at low temperature. The figures show that copolymers (C) and (D) are both much less stable than (A) and (B). Tertiary hydrogen and tertiary chlorine are... 

A number of decompositions of polymers are also described in Sect. 3.4 (Fig. 3.49). It is possible not only to use thermogravimetry to measure the thermal stability and life-time (see Sect. 4.6.6), but also to identify polymers by their degradation parameters such as temperature, degradation products, char residue, evolved gases, differences in reaction with O2 and other gases, etc. 

Thermogravimetry (or thermogravimetic analysis, TGA) is one of the oldest thermo-analytical procedures and has been used extensively in the study of polymeric systems. The technique involves monitoring the weight loss of the sample in a chosen atmosphere (usually nitrogen or air) as a function of temperature. It is a popular technique for the evaluation of the thermal decomposition kinetics of polymeric materials and hence provides information on thermal stability and shelf life. However, it is well known for its ability to provide information on the bulk composition of polymer compounds. 

The chemico-thermal stability of polymeric materials can be expressed by the mass loss at a particular temperature by thermogravimetry, since polymers are degraded by thermo-oxidative reactions. On the other hand, the thermal stability of the physical structure of materials is characterized by the softening temperature for... 

Thermal analysis techniques are used to study the properties of polymers, blends and composites and to determine the kinetic parameters of their stability and degradation processes.Here the property of a sample is continuously measured as the sample is programmed through a predetermined temperature profile. Among the most common techniques are thermogravimetry (TG) and differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) and dielectric spectroscopy are essentially extensions of thermal analysis that can reveal more subtle transitions with temperature as they affect the complex modulus or the dielectric function of the material. 

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