Abstract
Dynamic viscoelastic properties and elongational viscosities were measured for seven ABS samples having different morphorogy of rubber particles and molecular weights of matrix AS. The elongational viscosity exhibits a linear behavior in a range of strain less than 0.5, regardless of the molecular characteristics of ABS samples. In a region of strain higher than 0.5, the elongational viscosity strongly depends on the morphology of rubber particles and the molecular weights of the matrix AS. For the samples having higher modulus Gpa of the second plateau, the stronger increase of the elongational viscosity with the time is observed in the region of lower strain rate. For ABS which exhibits a linear viscoelstic behavior in the region of lower frequency, however, the elongational viscosity at small strain-rates seems to approach a constant value which is equal to 3η0. From these results it can be concluded that the time dependence of the elongational viscosity in the region of lower strain rate is qualitatively related to the dynamic viscoelastic behavior in the region of lower frequency.
For ABS samples having the same rubber particles, the stress-strain rate curves for different molecular weights can be superposed onto those for reference ABS by horizontal shift to give a master curve. The molecular weight dependence of the horizontal shift factor is 4.0, somewhat larger than 3.5.
