Stress Relaxation of Blended Polymers of Monodisperse Polystyrenes

Autor: Murakami, Kenkichi, Ono, Katsumichi, Shiia, Katsuo, Ueno, Taku, Matsuo, Masato
Zdroj: Polymer Journal; November 1971, Vol. 2 Issue: 6 p698-708, 11p
Abstrakt: The stress relaxation measurements of some blended polystyrenes were carried out. The blended polymers constructed from monodisperse polystyrenes with different molecular weights were used for this purpose. The effect of the molecular weight distribution on the shape of the relaxation spectrum is discussed. The rubbery regions of the relaxation spectra were characterized by a step-like shape if the molecular weight of each polymer component was larger than the critical molecular weight Mc. The molecular weight dependences of various viscoelastic parameters were examined. As for monodisperse polystyrenes, clear relations between the maximum relaxation time : tm, the steady flow viscosity ?t, and the molecular weight were observed, while for blended polystyrenes these relations showed some deviations. On the other hand, the viscoelastic parameters may be closely related to one another by the same equations in the cases of both the monodisperse and blended polystyrenes.
Databáze: Supplemental Index