The nonlinear rheology of an unentangled polymer melt under shear flow is considered theoretically. The finite chain extensibility is taken into account explicitly. The tangential stress and the first and the second normal-stress differences are calculated as a function of shear rate γ. It is shown that in the shear thinning regime, the viscosity η decreases as γ-2/3.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry