In polymer science, inherent viscosity is the ratio of the natural logarithm of the relative viscosity of a polymer to its mass concentration.[1] Inherent viscosity scales inversely to mass density, and a common unit is dL/g.
Inherent viscosity is defined as [2] where is the mass concentration of the polymer and is the relative viscosity, which is defined as where is the viscosity of the solution and is the viscosity of the solvent.
The definition of is a finite difference approximation to the derivative That ideal limiting value is the intrinsic viscosity,[3][4] which is a good measure of the polymerization degree.[5][6]
References
edit- ^ "Dilute Solution Viscosity of Polymers".
- ^ "IUPAC". doi:10.1351/goldbook.I03033.
- ^ Hester, Roger (2001). "Molecular Weight Determination By Dilute Solution Viscosity Measurements". Macrolab. University of Southern Mississippi.
- ^ Osuji 2009, §1.3: Intrinsic viscosity determination.
- ^ Osuji, Chinedum (February 5, 2009). "Size and Mass Characterization - Non Scattering (notes for ENAS 606: Polymer Physics)". Osuji lab. Yale University. §1.2.1: Intrinsic viscosity. Note that there are several typos in Osuji's displays, including an extra "c" in equation (7; §1.3); and a missing logarithm in the initial definition of inherent viscosity (§1.1).
- ^ "Reference: Polymer Properties" (PDF). Sigma-Aldrich. p. 51.