Viscosity average molecular weight formula

The second average is viscosity average molecular weight, M . This expression is obtained by using the exponent from the limiting viscosity number-molar mass relationship, a, as a power for the molecular weight of each molecule in the distribution. The formula for this average is... 

The viscosity-average molecular weight of a polymer sample may be computed from the chromatogram hi of the polymer by the formula ... 

For higher molecular weight polydimethyl siloxanes (Af > 2500), the number-average molecular weight is related to the bulk viscosity by the foUowiag formula, where the viscosity units are mm /s(=cSt). 

Polyether solutions of NiBf2 of the general formula, NiBr2(PEG) when n is the number of ether oxygens per cation, can be easily prepared over a wide composition range, typically n = 8 to 1000. With PEG of average molecular weight 400, the electrolytes are viscous liquids at room temperature, and their viscosity increases with salt concentration such that the most concentrated samples are solids at room temperature and must be heated to 100-150°C before the salt dissolves. 

Acker (133a) carried out a study of aggregation very similar to that of Audsley and Aveston. The initial polysilicic acid had a molecular weight of 2000 and reached about 3 X 10 at the gel point. The reduced viscosity, (ij, - l)/c, or [ij], where ij, is the viscosity relative to water, was related to the weight-average molecular weight by the formula... 

In addition, there is a great utility of having reliable values for both Mark-Houwink and Schultz-Blaschke parameters in that the combination enables the measurement of an average molecular weight in a very simple viscometry experiment. Equation 10.17 gives an explicit formula for the intrinsic viscosity based only on the relative flow times for a single concentration experiment. 

The common averages of a polymer molecular mass distribution arc number (m=l viscosity (m=1 +aX weight (m=2), and z or zeta average (m=3). What molecular mass average does the following formula calculate and of what property or "weighting" of the polymer sample is it a function ... 

---