viscosity at low shear rate,indicating that some flocculation
structures developed owing to the polar attraction between particles. However, with the increase of dimer acid content,the
thickness of the adsorbed layer becomes big,such that the steric
repulsion dominates the interaction of particles for a decrease of
viscosity to occur. In other words,the value of low shear rate
viscosity will,of course,depend on the extent and architecture of
flocculation formed in the CI/DA suspension.Moreover,though the
polar interaction may dictate the form of the suspension at low
shear rate,when the shear rate is greater than some critical value γ̇0, the viscosity will eventually approach similar values at high shear rate.To the best of our knowledge,this may be the first time
that the situation described above has been observed for MRFs.