Predictions of the linear viscoelastic complex shear modulus in model miscible blends of polyisoprene (PI) and poly(vinyl ethylene) (PVE) are compared with literature data. Using ideas of chain connectivity, the effective monomer relaxation times of PI and PVE in the blend were calculated using PI self-composition φ PI,s = 0.40 and PVE self-composition φ PVE,s = 0.80, determined in our earlier analysis of segmental dynamics in PI/PVE blends. The reptation times of PI and PVE were then determined from their effective monomer relaxation times in the blend, assuming a common tube for both components (thus specifying the blend plateau modulus). The component reptation times and effective terminal dispersion widths from fits to the pure component polymers were input along with the blend plateau modulus to the des Cloizeaux "double reptation" model of polymer dynamics to make predictions of blend linear viscoelasticity with no adjustable parameters. The calculated frequency dependence of the complex modulus of PI/ PVE blends was found to be in near quantitative agreement with experimental data, including the experimentally observed thermorheological complexity.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry