Rheological Behavior of Hydrogen Bonding Miscible Blend: High Molecular Weight Poly(2-vinyl pyridine) and Low Molecular Weight Poly(4-vinyl phenol)

抄録

We examined thermal and rheological behaviors for miscible polymer blends, poly(2-vinyl pyridine) / poly(4-vinyl phenol) (2VPy/VPh), in which intermolecular hydrogen bonds play an important role. The molecular weights of the 2VPy and VPh components are higher and lower than the critical sizes of the entanglement, respectively. In the mixture of these two polymers, only the 2VPy chains entangle each other, and the low molecular weight VPh is expected to act as a diluent. We found that the time-temperature superposition principle approximately held. The Williams-Landel-Ferry equation with a single parameter set (C₁ and C₂) could represent their shift factors by setting the reference temperatures to be T_g + 64 ºC. From the comparison of the composite curves, we found that the intermolecular hydrogen bonds did not affect the entanglement densities but made the zero shear viscosities larger and the relaxation times longer.