Mass increase during isothermal

Figure 8. DVS graph for a typical channel hydrate. These are typified by a greater mass increase during the hydration step than the mass decrease during the dehydration step. The corresponding isotherm plot would show significant hysteresis. The solid line indicates the mass change.

The dilation (or dilatation) of a partly solidified fat sample at a given temperature is the increase in specific volume (volume per unit mass) that occurs during isothermal complete melting at that temperature. The melting dilation of the fat at the same temperature is the increase in specific volume that would occur on complete melting if the sample was initially 100% solid. Dilation is the result of the expansion that occurs as a result of the solid to liquid phase change the specific volume of molten fat is about 10% greater than that of solid fat. 

Mass increase of a syndiotactic 1,2-polybutadiene (ex-JSR) sample during an isothermal TGA experiment at 240°C in air... 

The mass increase of an RB 830 syndiotactic 1,2-BR sample was measured as a function of time at 240°C in an air atmosphere. About thirty minutes were necessary to obtain a mass increase of 0.19 %wt. (0.22 %wt. during the non-isothermal experiment), see Figure 8.5. This sample was cooled and then placed in the DSC. A crystalline phase with a Tm- and Hf-value of respectively 9l°C and 23 J/g was detected the Tg-value of the amorphous phase proved to be -13°C. Hence, the Tg-, Tm- and Hf-values were not influenced at all by the samples heat treatment. Even the strength of the glass-rubber transition effect (0.26 J/g.°C) was not changed. Thus, the detected mass increase effect can not be explained by some cyclisation reaction of the BR. 

The experimental results and dynamics in the bed were analyzed by using a non-isothermal dynamic model incorporating mass, energy, and momentum balances. Although the temperature increase inside a bed is undesirable, in case of bulk separation, the temperature variation during the adsorption process is inevitable. Therefore, the... 

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