What is K in Mark Houwink equation?
What is K in Mark Houwink equation?
is intrinsic viscosity. K is a constant.
What is Huggins constant?
The constant kH is termed the Huggins constant and has values ranging from 0.3 in good solvents to 0.5 in poor solvents. It contains information about hydrodynamic and thermodynamic interactions between coils in solution.
How do you calculate intrinsic viscosity?
To determine the intrinsic viscosity at a shear rate approaching zero, polymer solutions can be measured at various shear rates. The viscosity values obtained are then extrapolated. The intersection with the y-axis gives the zero-shear intrinsic viscosity (Figure 6).
What is K value in viscosity?
K value (viscosity), is an empirical parameter closely related to intrinsic viscosity, often defined in slightly different ways in different industries to express viscosity based estimate of statistical molecular mass of polymeric material used particularly for PVC.
What is Mark-Houwink parameters?
Mark-Houwink parameters used are “k” = 2.79 x 10-3 cm3/g and “a” = 1.2754 at 25°C, data obtained from Tinland and Rinaudo [25] (Dependence of the Stiffness of the Xanthan Chain on the External Salt Concentration. Macromolecules 1989; 22: 1863-1865).
What do you understand with Mark-Houwink equation and for what purpose it is used?
From this equation the molecular weight of a polymer can be determined from data on the intrinsic viscosity and vice versa. It is named after Herman F. Mark and Roelof Houwink.
How do you calculate intrinsic viscosity from relative viscosity?
The intrinsic viscosity number is defined as the limiting value of the specific viscosity/concentration ratio at zero concentration. Intrinsic viscosity is determined by measuring the relative viscosity at several different concentrations and then extrapolating the specific viscosity to zero concentration.
What is specific viscosity in chemistry?
a measure of the resistance to flow of a fluid, expressed as the ratio of the absolute viscosity of the fluid to that of a reference fluid (usually water in the case of liquids)
What is the formula for relative viscosity?
Dividing the viscosity of the polymer solution (η) by the viscosity of the pure solvent (ηο) gives the relative viscosity with the dimensionless unit. Equation 7: Relative viscosity is the viscosity of the polymer solution divided by the viscosity of pure solvent.
Which one of the following equation is used to calculate the relative viscosity?
η=29(ρ−σ)gvr2.
What is PVC K value?
K Value of PVC resin: K – Value is a measure of degree of polymerization or number of monomers in PVC chain or molecular weight. Since the % of PVC in films and sheets is predominant, its K value plays a very important role. K – Value has effect on properties of PVC resin, processing as well as properties of product.
What is Brook Field viscometer?
The Brookfield viscometer is a rotational viscometer. To measure the viscosity, a measuring body (spindle) is immersed in the oil and rotated at a defined speed. The force required in order to keep this speed constant, is a measurement for the dynamic viscosity.
What is the significance of the Mark-Houwink equation?
The Mark–Houwink equation, also known as the Mark–Houwink–Sakurada equation or the Kuhn–Mark–Houwink–Sakurada equation or the Landau–Kuhn–Mark–Houwink–Sakurada equation gives a relation between intrinsic viscosity and molecular weight : From this equation the molecular weight of a polymer can be determined…
What is Houwink chromatography?
. It is named after Herman F. Mark and Roelof Houwink . In size-exclusion chromatography, such as gel permeation chromatography, the intrinsic viscosity of a polymer is directly related to the elution volume of the polymer.
What is Houwink virus used for?
For polymers with an absolute rigid rod, such as Tobacco mosaic virus, . It is named after Herman F. Mark and Roelof Houwink . In size-exclusion chromatography, such as gel permeation chromatography, the intrinsic viscosity of a polymer is directly related to the elution volume of the polymer.