Usually intrinsic viscosity is more related with molecular weight. we can calculate viscosity average molecular weight from IV. BUT intrinsic viscosity of a polymer is very different from "viscosity".
Here is the detail information of relation between viscosity and molecular weight
The intrinsic viscosity is a reflection of the size of a polymer molecule in solution. It is measured by precisely measuring the effect a polymer sample has on the viscosity of a solvent. The exact definition is the zero concentration value of 1/c * ln (viscosity of polymer solution/viscosity of the solvent). It is most accurately and easily determined using a forced flow relative viscometer, and very dilute (ca 0.1% wt/vol or less) solutions of the polymer of interest. The units are usually dl/g (deciliters per gram).
so, how can the molecular weight of a polymer for example poly-(ethylene oxide, Mv= 400,000) be calculated from its viscosity average molecular weight?
The viscosity average molecular weight can be calculated using the Mark Houinck relationship.
Needless to say, since typical polymers are mixtures of molecules of different sizes (from different degrees of polymerization), there are a range of sizes, and this range can be quantitatively described using the distribution concept, typically plotted as N vs M, where N is the relative number of molecules and M is the molecular mass.
The value obtained is an average for the distribution of sizes and molecular weights in the particular sample. If one assumes a particular distribution shape for a sample, the various moments of the distribution function can be calculated. (The first moment is called the number average molecular weight, the second moment is called the weight average molecular weight, the third moment is called the Z average molecular weight, and the fourth moment is called the Z+1, and so on.)
The various moments of the distribution generally correlate with mechanical properties of different time scales.
viscosity is the bulk property which have direct dependence on intermolecular forces in a liquid and where as molecular weight is the measure of sum of atomic weight of atoms in a molecule. So these two are related to each other. viscosity is internal property which directly related to the over all nautre of molecule which are the the consitutents of the liquid. Liquids nature depend upon the nature of individual atom which are forming the molecule. Nature of individual atom include its ionization energy, electron gain energy, atomic no, sheilding effect etc.
The intrinsic viscosity is quite different from plain viscosity.
Intrinsic viscosity has as its foundation Einstein's volume fraction concept for rigid spheres affecting the bulk viscosity of a fluid when the rigid spherical particles are at infinite dilution and zero shear rate. The application of this concept in polymer characterization produces data in density units (g/dL), and is measured using either a high performance relative viscometer with polymer concentrations so low that the relative viscosity is below 1.05 and at low shear rate is below 1000 /sec, or by the more tedious multiple dilution/extrapolation method using Huggin's plot or a variation thereof. A more detailed discussion can be found at . http://www.ias.ac.in/initiat/sci_ed/resources/chemistry/Viscosity.pdf
The bottom line of all this is that the intrinsic viscosity reflects the average size in solution of the macromolecules in a sample. Commonly, the Mark Houink relationship is used with the intrinsic viscosity to calculate a viscosity average molecular weight.
University of Pune
University of Central Florida
Aik Hwee Eng
Ansell Healthcare LLC
Santhana Krishnan G
National Aerospace Laboratories-Council of Scientific and Industrial Research (CSIR), New Delhi
Korea Institute of Industrial Technology
Ashraf Ali El-Saftawy
Egyptian Atomic Energy Authority
Hadi Kurniawan AR
University of Indonesia
Shiv Nadar University
Global Core Research Center for Ships and Offshore Plants,
An error occurred while rendering template.