Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Thermogravimetric analysis decomposition

T and by dsc, (onset of decomposition) Thermogravimetric analysis ia argon at 10°C heating rate. [Pg.260]

Thermal analysis using differential scanning calorimetry (dsc), thermogravimetric analysis (tga), and differential thermal analysis (dta) can provide useful information about organic burnout, dehydration, and decomposition. [Pg.310]

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]. [Pg.860]

Typical characterization of the thermal conversion process for a given molecular precursor involves the use of thermogravimetric analysis (TGA) to obtain ceramic yields, and solution NMR spectroscopy to identify soluble decomposition products. Analyses of the volatile species given off during solid phase decompositions have also been employed. The thermal conversions of complexes containing M - 0Si(0 Bu)3 and M - 02P(0 Bu)2 moieties invariably proceed via ehmination of isobutylene and the formation of M - O - Si - OH and M - O - P - OH linkages that immediately imdergo condensation processes (via ehmination of H2O), with subsequent formation of insoluble multi-component oxide materials. For example, thermolysis of Zr[OSi(O Bu)3]4 in toluene at 413 K results in ehmination of 12 equiv of isobutylene and formation of a transparent gel [67,68]. [Pg.90]

Figure 6. Thermogravimetric analysis (TGA) of free 55 K PVP and 7.1 nm Pt-PVP nanoparticles in oxygen. Oxidative decomposition of free PVP begins at 573K, while significant weight loss due to the catalyzed oxidation of PVP on PVP-protected Pt nanoparticles occurs at 473 K. It appears that PVP layer is not a complete monolayer or the entanglement of PVP chains causes a porous polymer layer enabling oxygen diffusion to the nanoparticle surface [17]. (Reprinted from Ref [17], 2006, with permission from Springer.)... Figure 6. Thermogravimetric analysis (TGA) of free 55 K PVP and 7.1 nm Pt-PVP nanoparticles in oxygen. Oxidative decomposition of free PVP begins at 573K, while significant weight loss due to the catalyzed oxidation of PVP on PVP-protected Pt nanoparticles occurs at 473 K. It appears that PVP layer is not a complete monolayer or the entanglement of PVP chains causes a porous polymer layer enabling oxygen diffusion to the nanoparticle surface [17]. (Reprinted from Ref [17], 2006, with permission from Springer.)...
Thermal Properties. The glass transition temperature (Tg) and the decomposition temperature (Td) were measured with a DuPont 910 Differential Scanning Calorimeter (DSC) calibrated with indium. The standard heating rate for all polymers was 10 °C/min. Thermogravimetric analysis (TGA) was performed on a DuPont 951 Thermogravimetric Analyzer at a heating rate of 20 °C/min. [Pg.157]

Thermogravimetric analysis (TGA) of these poly(phosphazenes) shows their decomposition onset temperatures in an inert atmosphere to be ca. 350 to 400°C, depending on the side group. These temperatures are ca. 25-75°C higher than that reported for commercial materials based on the fluoroalkoxy substituted polymer, [(CFgCHjO PN],. (19) Interestingly, methyl rather than phenyl side groups yield the more stable materials, as shown by... [Pg.286]

In this study, we extend the range of inorganic materials produced from polymeric precursors to include copper composites. Soluble complexes between poly(2-vinylpyridine) (P2VPy) and cupric chloride were prepared in a mixed solvent of 95% methanol 5% water. Pyrolysis of the isolated complexes results in the formation of carbonaceous composites of copper. The decomposition mechanism of the complexes was studied by optical, infrared, x-ray photoelectron and pyrolysis mass spectroscopy as well as thermogravimetric analysis and magnetic susceptibility measurements. [Pg.430]

Thermogravimetry (TG) is a measure of the thermally induced weight loss of a material as a function of the applied temperature [45]. Thermogravimetric analysis is restricted to studies that involve either a mass gain or loss, and it is most commonly used to study desolvation processes and compound decomposition. The major use of TG analysis is in the quantitative determination of the total volatile content of a solid. When a solid can decompose by means of several... [Pg.17]

When a solid is capable of decomposing by means of several discrete, sequential reactions, the magnitude of each step can be separately evaluated. Thermogravimetric analysis of compound decomposition can also be used to compare the stability of similar compounds. The higher the decomposition temperature of a given compound, the more positive would be the DG value and the greater would be its stability. [Pg.245]

TA instruments has developed automated thermogravimetric analysis and related kinetic programs that enable a rapid determination of decomposition rates to be made. The following excerpt from a TA application brief [57] explains the method ... [Pg.106]

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. [Pg.88]

In Thermogravimetric analysis a sample of material is heated at a fixed rate whilst the mass of the sample is continuously recorded. This technique identifies de-hydration, de-solvation and decomposition. [Pg.50]

The nature of the material to be studied, which means its degree of crystallinity and perfectness of crystal structure, may have a significant effect on the thermoanalytical behavior. In spite of identical chemical composition of a certain material the variations with respect to structure, imperfections, grain boundaries, etc. are almost infinite. Of course many of these will not show in normal thermogravimetric analysis, with very sensitive apparatus characteristically different TG curves18, 19 may be obtained however. As an example Fig. 26 shows the thermal decomposition of hydrozincite, Zn5(OH)6(003)2, whereby equal amounts of samples from natural origin and synthetic preparations are compared. [Pg.108]

Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) curves of the Ag/Si02 sample prepared by the two-step method are shown in Fig. 6.10. The TGA curve exhibits two evident weight loses, which are in the range of ca. 100 to 250°C and 250 to 550°C, corresponding to the loss of solvent, water, ethanol and THF, and the decomposition of organic silica, respectively. Four evident endothermic peaks can be observed from DTA curve, which centered at ca. 200°C, 350°C, 425°C and 480°C, respectively. [Pg.84]

All the polyimides are thermostable. They do not melt before decomposition at high temperature. In thermogravimetric analysis, the decomposition starts at more than 400°C. [Pg.585]

Aminopolysaccharides 9 and 10 can be expected to have unusual properties because of the hyperbranched structure. The thermal properties of 9 and 10 were examined (Figure 2) by thermogravimetric analysis (TGA). The TGA curve of 9 shows that decomposition of the tosyl group started at 166°C and showed a 45% weight loss up to 337°C. The residual material exhibited thermal resistance above 337°C, but a second weight loss occurred at... [Pg.265]

Thermogravimetric analysis (TGA) showed [120] that the weight losses in the first and second step decomposition for the 5 h milled powder were 2.37 and 0.08 wt%, respectively. Corresponding weight losses for the 10 h milled powder were 2.14 and 0.02 wt%. Assuming the MCAS is completed (i.e., products have a 1 mol of MglAlH ) and 2 mol of NaCl), the theoretical hydrogen capacity in the mixture... [Pg.227]


See other pages where Thermogravimetric analysis decomposition is mentioned: [Pg.287]    [Pg.287]    [Pg.327]    [Pg.496]    [Pg.439]    [Pg.444]    [Pg.299]    [Pg.361]    [Pg.894]    [Pg.430]    [Pg.213]    [Pg.91]    [Pg.430]    [Pg.24]    [Pg.235]    [Pg.298]    [Pg.18]    [Pg.245]    [Pg.313]    [Pg.84]    [Pg.88]    [Pg.24]    [Pg.33]    [Pg.106]    [Pg.106]    [Pg.367]    [Pg.469]    [Pg.100]    [Pg.195]    [Pg.10]    [Pg.19]    [Pg.233]    [Pg.89]   
See also in sourсe #XX -- [ Pg.108 , Pg.109 ]




SEARCH



Applications, thermogravimetric analysis decomposition

Decomposition analysis

Thermogravimetric analysis

Thermogravimetric analysis decompositions, solid-state

Thermogravimetric decomposition

© 2024 chempedia.info