VISCOELASTIC PROPERTIES OF HOMOGENEOUS POLYMER BLENDS IN THE TERMINALREGION

Viscoelastic properties of homogeneous polystyrene/poly(vinyl methyl e ther) (PS/PVME) blends were studied in terms of the zero-shear viscosi ty eta(0) and the steady-state compliance J(e). The molecular weight a nd composition of PS (M(PS) and phi(PS)) were varied, whereas the mole cular weight of PVME (M(PVME)) was fixed, maintaining the condition M( PS) >> M(PVME). The behavior of eta(0) and J(e) was discussed as a fun ction of M(PS) and phi(PS). In the entangled region, eta(0) Can be exp lained by the scaling law, in-the same way as in the semidilute polyme r solutions, if phi(PS) < 0.25. The magnitudes of J(e) and its M(PS) a nd phi(PS) dependences are comparable to those of polymer solutions in the nonentangled region. Therefore, it is concluded that the viscoela stic properties of homogeneous PS/PVME blends in the terminal region s tudied here are very similar to those of the polymer solutions if M(PS ) >> M(PVME).