ISSN:
0098-1273
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Measurements of apparent viscosity, normal stress coefficient, and storage and loss moduli have been used to determine the characteristic relaxation time. The ratio of the characteristic relaxation time θin corresponding to a given deformation rate ·γ to that of the initial state θe is found to be a function of ·γθin. For a wide range of polymeric systems, the ratio of normal stress to the initial high elasticity modulus and to the high elastic deformation γe are the same function of ·γθin. It has been established that γe, like other viscoelastic characteristics of polymer systems, is determined by the relaxation properties and their variation due to deformation. The dependence of γe on θe/θin is common to a wide range of polymeric systems. The generalized characteristics were independent of the nature of the polymeric chain, molecular weight, molecular weight distribution, temperature, polymer concentration in solution, and solvent type. These results allow us to describe approximately normal stresses and high-elastic deformations as functions of shear rate and storage and loss moduli as functions of frequency, if we know θin the relation between shearing stress and shear rate.
Zusätzliches Material:
7 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1973.180111104
Permalink
