Mercury dilatometry

R.F. Boyer Simha s measurements above Tg were made via mercury dilatometry, starting out with polymer pellets. ... 

The characteristics of the pore system in reservoir rocks is important for the understanding of the flow of liquids through the rocks, particularly in relation to the recovery of hydrocarbons. Commonly used methods in the assesment of these characteristics of reservoir rocks are optical microscopy of thin sections and measurements of total porosity by mercury dilatometry and of air or liquid permeabilities. 

A special apparatus has been described that is claimed to be simpler to operate than most other methods for the determination of the apparent density of porous carbons [117]. The apparatus is designed so that the solid can be thoroughly outgassed in order that degassed dilatometrie liquid can be brought into contact with it without exposing the latter to the atmosphere. Other procedures involve the use of mercury [118] to... 

Acrylate- and methacrylate guanidines (AG and MAG) were prepared with high yield (to 80%) by reaction of acrylic acids and guanidine according to method elaborated by authors of this article and described in work [1], Kinetics of AG and MAG monomers polymerization was studied by dilatometry method in bidistillated water (pH 6.5, 60°C) on low conversion degrees (< 5%) after preliminary degassing of reaction mixtures on vacuum equipment (103 millimeters of mercury). Ammonium persulfate (APS) was used as initiator. The degree of conversion of monomer into polymer was determined on the base of contraction values determined by densimetry method which for GA polymerization reaction in water was 10.8%, and for MAG - 7.0%. Intrinsic viscosities [r ] of polymers were determined IN solution of NaCl in water at 30°C. Relative viscosities r rei of reaction solutions were determined at 30°C. 

Volume versus temperature Dilatometry (polymer confined by mercury)... 

If the pressure coefficient and the enthalpy of the transition are known, the volume change of the transition can be calculated. From the value obtained above for the latent heat, Equation (1) predicts a volume increase, SV/V, of order 0.1 % at the LCOT for the Mw=85K P(rf-S-Ii-nBMA) at atmospheric pressure. To confirm the volume change experimentally, dilatometric techniques are usually employed, where mercury displacement in a fine bore capillary provides the high precision necessary to detect such small changes. Although dilatometry studies are in progress, x-ray reflectivity was employed as an altmiative route to access bV/V experimentally where a high precision in the measurement of thickness can be achieved. 

In dilatometry, a sample of polymer is enclosed in mercury within a glass bulb from which a capillary tube extends. The level of mercury in the capillary is recorded as the temperature is changed. An abrupt change in volume occurs at the melting point. With appropriate calibration, a plot of polymer-specific volume against temperature can be obtained such is illustrated in Fig. 18.13. 

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