ISSN:
1436-2449
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Summary The steady state radial pressure distribution in the truncated cone-and-plate (TCP) apparatus has been measured for a highly elastic polyisobutylene solution in cis-trans decalin (MW=4300 kgmol−1 MW/Mn=2) at eight shear rates from 1 to 270 s−1 and temperatures of 3.0, 20.0, 30.0 and 46.0° C. The slope of pressure, corrected for inertia by the classical formula, versus the logarithm of radius provides a combination of normal stress differences N1+2N2 with a typical experimental scatter of 1 % at all measured temperatures and shear rates. The plots of N1+2N2 versus shear rate can be shifted, without loss of accuracy, by means of the time-temperature superposition principle, the shift factors strictly adhering to a WLF equation. Extrapolated rim pressures, when corrected for elastic hole pressure with a theoretical equation, give values of the second normal stress difference with typically less than 10 % of experimental scatter. Contrary to previous analyses of the TCP apparatus, the center-hole pressure is found to give a useful estimate of the second normal stress difference, although there are insufficient data at present to perform the differentiation of a nonlinear function required in the analysis of the data. Instrument imperfections are reviewed briefly in the Appendix.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00272233
Permalink
