Reduced viscosity

In fluid dynamics, the reduced viscosity of a polymer is the ratio of the relative viscosity increment (${\displaystyle \eta _{i}}$) to the mass concentration of the species of interest (c). It has units of volume per unit mass.^[1]

The reduced viscosity is given by

$${\displaystyle {\frac {\eta _{i}}{c}},}$$

where ${\displaystyle \eta _{i}}$ is the relative viscosity increment given by ${\displaystyle \eta _{i}={\frac {\eta -\eta _{s}}{\eta _{s}}}}$ (Where ${\displaystyle \eta _{s}}$ is the viscosity of the solvent.)^[1]