Zero-shear viscosity of branched polymer solutions

The zero-shear viscosity η° of star-shaped polymers with different numbers of branches in good solvents were analyzed using the scaling theory of de Gennes. It was concluded that the semidilute region exists in the viscosity behavior of branched polymers if the molecular weight of branches are high enough. The scaling theory agrees with experimental data of the branched polymers if we recognize that the molecular weight dependence of zero-shear viscosity is higher for branched polymers than for linear polymers.