ISSN:
1435-1528
Schlagwort(e):
Internal viscosity model
;
theta solution
;
non-Newtonian viscosity
;
complex viscosity
;
intrinsic viscosity
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Abstract A stress-symmetrized internal viscosity (I.V.) model for flexible polymer chains, proposed by Bazua and Williams, is scrutinized for its theoretical predictions of complex viscosityη * (ω) =η′ − iη″ and non-Newtonian viscosityη (τ), whereω is frequency andτ is shear stress. Parameters varied are the number of submolecules,N (i.e., molecular weightM = NM s ); the hydrodynamic interaction,h *; andφ/f, whereφ andf are the I.V. and friction coefficients of the submolecule. Detailed examination is made of the eigenvaluesλ p (N, h *) and how they can be estimated by various approximations, and property predictions are made for these approximations. Comparisons are made with data from our preceding companion paper, representing intrinsic properties [η], [η′], [η″] in very viscous theta solutions, so that theoretical foundations of the model are fulfilled. It is found that [η′ (ω)] data can be predicted well, but that [η (τ)] data cannot be matched at highτ. The latter deficiency is attributed in part to unrealistic predictions of coil deformation in shear.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01357950
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