Z average molecular mass

For correlation with most physical properties (mechanical strength, optical scattering), mass average molecular mass of a polymer Mw" appears more satisfactory. Higher-power averages like z-average molecular mass "Mz" seem to better correlate with rheological properties. Expressions of M , Mw and Mz are... 

Z-average molecular mass, 18 Zero point molar volume, 76 Zimm plot, 310... 

If the polymer solution is sedimented in a gravitational field, the difference between refiactive index of the solution and solvent compared at any two positions down the sedimentation gradient will be a function of the z average molecular mass,. ... 

The presence of high molecular mass fractions, which often impairs the solubility of a resin, can best be recognized by the Z-average molecular mass Mz-... 

Number average molecular mass Weight average molecular mass z-average molecular mass Number of crystallizable elements Isotactic poly(4-methylpentene-1)... 

D (7y notation employed for block copolymers, where the subscripts (w and y) denote the composition in weight percent and the superscripts (x and z) the number-average molecular mass in kilograms per mole. In the case of PPDX-fr-PCL diblock copolymers, the letter D is used for PPDX and the letter C for PCL... 

Z-average molecular weight (Af ) This is also determined by ultracentrifugation technique. The molecular weight depends both on size and mass of the molecules. However, the contribution of the mass of the particle are weighed further in this type of molar mass. Mathematically, is given as... 

This relation can be solved for the superficial velocity, provided that the density is known from a appropriate EOS. For gas mixtures the ideal gas law is often used, thus the changes in composition is taken into account through the average molecular mass of the mixture. Moreover, the continuity equation can be integrated from the inlet z = 0 to any level z = z, to show that the mass flux is constant in the tube pv ) z = (/W ) in = Constant kg/m s). In particular, this integral relationship is frequently used to simplify the models, calculating the convective/advective flux terms from the known inlet values. 

Stabilizer Average molecular mass T ,elt C Z, nm in C2H5OH Conservation in % spec. 

The experimentalist measures quite easily the mass concentration p, an average molecular mass (i.e. Afw), an average mean square radius of gyration in the limit of zero concentration (i.e. Rg,z), and an average second virial coefficient A2 To these crude quantities correspond the basic quantities... 

Knowledge of the conversion factor °A allows us also to determine the average molecular mass Mz from the Z average of the square radius of gyration. Indeed, in the Brownian case, relation (15.2.4) can be written... 

The third quantity is called the z-average relative molar mass or simply the z-average molar mass denoted and defined as the weighed average of the mass fraction of each macromolecule having a given molecular mass. 

Confirmation of the modification of the hydroxyl end groups from the PPG can be accomplished by analysis using MALDI-TOF MS [59]. An example MALDI-TOF mass spectrum of a prepolymer based on PPG 2000 is shown in Figure 28. End group and average molecular weight data can be gleaned from the spectrum. The dominant distribution of peaks centred at approximately m/z 2,500... 

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