\(\left( {M_w ,\overline M _w } \right)\) For a sample with distributed molecular weights (all commercial polymers), the defining equation is
where N i is the number of individual molecules having molecular mass M i and N i M i equals the mass of the N i molecules in the sample with molecular mass M i . The numerator and denominator quantities are also known as the second and first original moments of the distribution. M w may be determined from measurements of Light Scattering or Size-Exclusion Chromatography. And it is M w upon which melt viscosity in thermoplastics is strongly dependent. (Allcock HR, Mark J, Lampe F (2003) Contemporary Polymer Chemistry. Prentice Hall, New York; Slade, P. E., Polymer Molecular Weights, Vol. 4, Marcel Dekker, New York, 2001; Coleman, M. M., and Strauss,...
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© 2011 Springer Science+Business Media, LLC
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Gooch, J.W. (2011). Weight-Average Molecular Weight. In: Gooch, J.W. (eds) Encyclopedic Dictionary of Polymers. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-6247-8_12767
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