Capillaiy viscometer

The viscosity of a 0.02% solution of polyethylene powder in decahydronapthalene was measured by means of an Ubbelohde capillaiy viscometer. The measurement yielded an average solution flow time of 124 seconds vs. 72.3 seconds for the pure solvent. A Hagenbach (k) correction factor of 2.02 seconds was previously determined for this particular viscometer. What is the nominal molecular weight of the polyethylene sample Would this polyethylene be classified as an UHMWPE ... 

D2171 Test Method for Viscosity of Asphalts by Vacuum Capillaiy Viscometer ... 

Baglejr has developed a method for getting the true pressure gradient from capillaiy viscometer data. As seen in Fig. 16.4,... 

Rheology and Wilhelmy plate method. The relative viscosities were determined by using a capillaiy viscometer (capillary diameter 0.6 mm). The measurements were carried out at 25 °C. For surface tension measurements a digital tensiometer KIOT of KrCiss was used equipped with a platinum plate. 

The shear rate calculated from impeller rotational speed is used to identify a viscosity from a plot of viscosity versus shear rate determined with a capillaiy or rotational viscometer. Next Nr is calculated, and Np is read from a plot like Fig. 18-17. 

Solution viscosities of linear polymers relate empirically to their molecular weights. This is used in various ways in industry to designate the size of polymers. The values are obtained by measuring the efflux time t of a polymer solution through a capillaiy. It is then related to the efflux time of pure solvent. Typical viscometers, like those designed by Ubbelohde, Cannon-Fenske, (shown in Fig. 1.3), and other similar ones are utilized and measurements are carried out in constant temperature baths. The viscosity is expressed in following ways ... 

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