Theory of Viscoelasticity in Temporarily Crosslinked Polymers (II) Relaxation Spectrum and Steady Flow Viscosity

1963 ◽  
Vol 18 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Shizuo Hayashi
Keyword(s):  
Steady Flow ◽  
Relaxation Spectrum ◽  
Crosslinked Polymers ◽  
Theory Of Viscoelasticity

Influence of Vibrations on the Viscoelastic Behavior of Monodisperse Polybutadienes

1972 ◽  
Vol 45 (4) ◽  
pp. 1082-1093
Author(s):  
G. V. Vinogradov ◽  
Yu G. Yanovsky ◽  
A. I. Isayev ◽  
V. P. Shatalov ◽  
V. G. Shalganova
Keyword(s):  
Linear Theory ◽  
Cyclic Deformation ◽  
Relaxation Spectrum ◽  
Relaxation Times ◽  
Viscoelastic Behavior ◽  
Logarithmic Scale ◽  
Continuous Deformation ◽  
Long Time ◽  
Short Time ◽  
Theory Of Viscoelasticity

Abstract The viscoelastic behavior of monodisperse polybutadienes is studied at different amplitudes of cyclic deformation. The concept of initial relaxation spectrum is introduced, this spectrum corresponding to small amplitudes. Under the action of high amplitudes the relaxation spectrum changed. This changed-effective spectrum can be calculated by means of the linear theory of viscoelasticity. The initial spectra of monodisperse polybutadienes have maxima. Under the action of high amplitudes the long-time parts of the spectra are truncated and the maxima shift into the short-time regions. There is an unambiguous correspondence between the amplitude of the deformation rate on cyclic deformation and the rate of shear on continuous deformation. It is shown that the length of the high-elasticity plateau, estimated on a logarithmic scale of relaxation times, and the maximum relaxation times of polybutadienes, as well as their initial Newtonian viscosities are dependent on molecular weight to a power of 3.6. The apparent viscosity is calculated, making use of the approximate initial relaxation spectrum concept, the law of change of its long-time boundary with the shear rate, and the commonly known relation of the linear theory of viscoelasticity. The results of these calculations were found to agree approximately with the data obtained under conditions of continuous deformation.

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