Visualization of Structural Deformation of Polymer Additives in Oil Under High Shear Flow

Abstract Using a powerful synchrotron radiation X-ray source, we developed a cell that can perform Small Angle X-ray Scattering (SAXS) measurements under high shear (~ 105 s− 1 ). We successfully and quantitatively visualized the deformation of polymer chains as polymer additives in oil under high shear. We found that poly(alkylmethacrylate) (PMA) with the lowest molecular weight was not deformed by the shear flow and did not show the shear thinning behavior. On the other hand, the other PMAs were deformed and exhibited shear-thinning behaviors. The correlation suggests that the shear thinning behaviors are caused by the elongation of polymer chains under shear. The shear thinning behaviors moderate the temperature dependence of the viscosity at a higher shear rate. We, thus, need to consider the effects of the deformation of the polymer on the effectiveness of modifiers at high molecular weight.