Shear mixing and phase diagram shift of polymer blends

For a low molecular weight polystyrene/polybutadiene blend, the effect of shear on the suppressing of critical fluctuations and the critical temperature has been studied and is in good agreement with the predictions of Onuki and Kawasaki. By assuming the symmetry of this critical scaling into the two phase region, together with the Taylor theory, the observed (phase separated) droplet break-up and the formation of string pattern can be explained. The exact shear dependence of T_c(γ) can be obtained by the use of the fluorescence microscope under steady shear.