n . An averaged molecular weight for high polymers that relates most closely to measurements of dilute-solution viscosities of polymers. The defining equation is
where N i is the number of individual molecules having the molecular mass M i. The exponent a, between 0.6 and 0.8 for many polymer/solvent systems, is best evaluated from measured viscosities of dilute solutions of narrow-molecular-mass fractions of polymers, determining the intrinsic viscosity [η] for each fraction, then fitting the following equation to the data: [η] = K 1 M a. For a = 1, occasionally seen, M v = the weight-average molecular weight, M w.
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References
Kamide K, Dobashi T (200) Physical chemistry of polymer solutions. Elsevier, New York.
Slade PE (2001) Polymer molecular weights, vol. 4. Marcel Dekker, New York.
Elias HG (1977) Macromolecules, vols 1–2. Plenum Press, New York.
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(2007). Viscosity-average molecular weight. In: Gooch, J.W. (eds) Encyclopedic Dictionary of Polymers. Springer, New York, NY. https://doi.org/10.1007/978-0-387-30160-0_12355
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