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:
The effects were studied of molecular weight, shear rate, and temperature on the viscous behavior of various linear, monodisperse polyisoprenes of about 90% cis-1,4 structure. Viscosities of from 1010-105 poise were measured on a double cone and plate viscometer while viscosities of 104-10-2 poise were measured on rotating cylinder viscometers. For such polyisoprenes the variation of Newtonian (zero shear) viscosity η with the weight-average molecular weight in the molecular weight range of 2 × 104-1 × 106 may be represented as \documentclass{article}\pagestyle{empty}\begin{document}$\eta = A\bar M_w^{3.9_5}$\end{document} where A is a temperature-dependent parameter given by \documentclass{article}\pagestyle{empty}\begin{document}$\log A = - 101.14 + \frac{{8.999 \times 10^4}}{T} - \frac{{3.19222 \times 10^7}}{{T^2}} + \frac{{3.816 \times 10^9}}{{T^3}}$\end{document} The variation of the apparent viscosity ηa with shear rate is also determined and a combined equation may be formulated as \documentclass{article}\pagestyle{empty}\begin{document}$\eta _{\rm a} = A\bar M_w^{3.9_5} /[1 + 1.22(A\dot \gamma /T)^{0.58} \bar M_w^{2.87} \times 10^{- 5}]$\end{document} This equation is compared with other expressions for the variation of viscosity with molecular weight, temperature, and shear rate.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1965.070090824
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