Thermal gravimetric analysis solvents

Thermal Gravimetric Analysis/Solvent Extractables - We have used both methods to characterize the change in curing behavior induced by varying light intensity, type and concentration of crosslink agent. 

The heavy metal salts, ia contrast to the alkah metal salts, have lower melting points and are more soluble ia organic solvents, eg, methylene chloride, chloroform, tetrahydrofiiran, and benzene. They are slightly soluble ia water, alcohol, ahphatic hydrocarbons, and ethyl ether (18). Their thermal decompositions have been extensively studied by dta and tga (thermal gravimetric analysis) methods. They decompose to the metal sulfides and gaseous products, which are primarily carbonyl sulfide and carbon disulfide ia varying ratios. In some cases, the dialkyl xanthate forms. Solvent extraction studies of a large number of elements as their xanthate salts have been reported (19). 

On the other hand, the P—E bond is rather labile toward hydrolysis by even trace amounts of moisture in nonaqueous solvents, producing a series of corrosive products (Scheme 5). Thermal gravimetric analysis (TGA) reveals that, in a dry state, LiPFe loses 50% of its weight at >200 °C but that, in nonaqueous solutions, the deterioration occurs at substantially lower temperatures, for example, as low as 70 X. 

The diorgano tellurium dicarboxylates are white, crystalline materials that are soluble in organic solvents and stable towards atmospheric agents. Diaryl tellurium diacetates can be boiled in water without decomposition. However, bis[trifluoromethyl] tellurium bis trifluoroacetate] was reported to be moisture-sensitive. Aqueous sodium hydroxide converts diaryl tellurium dicarboxylates to diaryl tellurium oxides or dihydroxides . Thermal gravimetric analysis of diaryl tellurium dicarboxylates indicated that these compounds lose carbon dioxide at 240-260° and form the tetraaryl tellurium derivatives. The tetraorgano tellurium compounds decompose slowly to the diaryl tellurium compounds and hydrocarbons. ... 

HPLC and GC analyses are two commonly used methods for determining the levels of impurities and residual solvent in the cake. Thermal gravimetric analysis is another very powerful tool. It detects not only the level of residual solvent, but also the temperature at which the solvent evaporates. If the cake weight loss due to solvent evaporation occurs at the melting point of the solid, this is a clear indication that solvent is trapped within the cake. 

There are several nonspecific methods available that can determine the total amount of solvent(s) in a sample. Loss on drying (LOD) determines the amount of volatile components that are released from a sample under specific temperature and/or vacuum conditions. Thermal gravimetric analysis (TGA) measures the loss of volatile components from a sample over a temperature gradient. The advantage of these methods is that they give an estimate of the volatile component content of a sample relatively quickly. The disadvantages of these methods are that they do not speciate and cannot account for volatile components that are trapped in the lattice structure of the compound. By accepting the limitations of these methods, a total solvent amount can be... 

Thermal gravimetric analysis and solvent extraction were used to study the change in curing behavior upon changing the light intensity or the type and concentration of the crosslinking agent. 

Glass transition temperatures were measured on a DuPont dynamic scanning calorimeter with a heating rate of 10 T/min. Thermal gravimetric analysis was carried out a heating rate of 10 T/min. Gel Permeation chromatography was carried out with a THF mobile phase and polystyrene standards. Films of homopolymers and copolymers were prepared by doctor-blading chloroform solutions followed by solvent removal on a hot plate. 

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