Shear Flows of Liquid Crystal Polymers: Measurements of the Second Normal Stress Difference and the Doi Molecular Theory

The shear rate dependence of the second normal stress difference (N 2 ) has been measured for various solutions of poly (γ-benzyl L-glutamate). The rheology of the isotropic phase is more or less similar to that of a typical concentrated polymer solution. By contrast, the liquid crystalline phase exhibits a number of distinctive rheological features. A recently published version of the Doi molecular theory successfully described the essential features of liquid crystal behavior in steady shear flow