Question

Differentiate between relative and reduced viscosity

Answer 1

Some important things-

Reduced viscosity is equal to the ratio of the relative viscosity increment ( η i {\displaystyle \eta _{i}} ) to the mass concentration of the polymer.[1]

Reduced viscosity: η i c {\displaystyle {\frac {\eta _{i}}{c}}} . The unit must be specified; mL/g is recommended.

Relative viscosity increment: η i = η − η s η s {\displaystyle \eta _{i}={\frac {\eta -\eta _{s}}{\eta _{s}}}}

Now the Difference-

Relative viscosity ( ) (a synonym of "viscosity ratio") is the ratio of the viscosity of a solution ( ) to the viscosity of the solvent used ( ), .

It is the ratio of the viscosity of a solution or dispersion to the viscosity of the solvent or continuous phase.

But Reduced viscosity is equal to the ratio of the relative viscosity increment ( ) to the mass concentration of the polymer. Reduced viscosity: . The unit must be specified; mL/g is recommended.