Molecular weight distribution number average

See also molecular weight, molecular weight distribution, number average molecular weight, and viscosity-average molecular weight. 

Molecular Weight Distribution. The ratio of weight-average molecular weight to number-average molecular weight of PET obtained by the addition of the chain extenders measured by gel permeation chromatography is shown in Table V. 

Polymerization of 2-triethylsilyl-l, 3-butadiene initiated by n-butyl-lithium in hexane yielded (E)-l, 4-poly(2-triethylsilyl-l, 3-butadiene). The molecular weight distribution (as determined by gel permeation chromatography) of the polymers depended on the ratio of monomer to initiator concentrations. Polymers of low polydispersity (Mu [weight-average molecular weight]/Mn [number-average molecular weight] = 1.3-1.6) and with up to 110,000 w re obtained. The... 

The colour bar in Fig. 15.11 represents the normalised number average molecular weight. The number average molecular weight distribution of three cases various. It is, therefore, known that the parameters they used in these three cases are located in the... 

Since nearly every collection of polymer molecules contains a distribution of molecular weights, a number-average molecular weight M may be defined in an analogous fashion to Equation 5.3 ... 

The phenomena we discuss, phase separation and osmotic pressure, are developed with particular attention to their applications in polymer characterization. Phase separation can be used to fractionate poly disperse polymer specimens into samples in which the molecular weight distribution is more narrow. Osmostic pressure experiments can be used to provide absolute values for the number average molecular weight of a polymer. Alternative methods for both fractionation and molecular weight determination exist, but the methods discussed in this chapter occupy a place of prominence among the alternatives, both historically and in contemporary practice. 

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