ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Capillary viscometer measurements for a number of polyethylenes and polystyrenes reveal deviations from linearity in plots of applied pressure versus capillary length to diameter ratio, at constant rates of shear, resulting in apparently negative end corrections. This is contrary to previous physical considerations. Some polymers obey Hooke's law in shear permitting the separation of the end correction into two components. A Couette correction, dependent upon the capillary dimensions, is constant for any given polymer, shear rate, and temperature; an elastic shear strain correction, dependent upon the transit time through the capillary, may be determined by post-extrusion measurements. Determination of these two correction leads to linear plots of pressure versus capillary length to diameter ratio and enables flow curves to be calculated independent of the capillary dimensions and the swell properties of the polymer.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1969.070130519
