Integral molecular weight distribution

Figure 8. Weight differential and integral molecular weight distribution plots.

At any i, CRi is, of course, a weight fraction concentration of solute based on or referenced to the concentration of the plateau region. When considered as a weight fraction concentration, CRi will be denoted as W. A plot of Wi versus s is the integral molecular weight distribution for a sample. 

Figure 7. A plot of the integral molecular weight distribution for the poly(l-amidoethylene) standard.

Calculated from integral molecular weight distribution curves. 

Figure 5. Integrated molecular-weight distribution of SRC-II obtained by total sample vaporization from solids probe...

A typical GPC chromatogram is shown in Figure 15, and the results of a series of methylated DVE-MA copolymers along with DVE+DMFMT are shown in Table 1. The integral molecular weight distributions of copolymers of DVE-MA, DVE+ DMFMT, and the methylated DVE-MA copolymers are shown in Figure 16. 

Fig. 16. Integral molecular weight distribution of copolymers of maleic anhydride and divinyl ether and...

Fig. 4. Integral molecular weight distribution curves of nylon 6j6 on the basis of fractionation in m-cresol/cydohexane. The number of fractions inoeases in the sequence 1, 2,3 9)...

Mathematical models of the reaction system were developed which enabled prediction of the molecular weight distribution (MWD). Direct and indirect methods were used, but only distributions obtained from moments are described here. Due to the stiffness of the model equations an improved numerical integrator was developed, in order to solve the equations in a reasonable time scale. 

Also, the zeroth moment of the differential molecular weight distribution, DMWD, may be obtained by integration of the simplified equation ... 

Shimadzu Xex = 486nm, A,em = 516 nm) with a chart recorder (Fisher Recordall, Series 5000, Springfield, NJ). F-PHEA concentrations in perfusate were determined by area comparison of the eluted curves to that of the standard. Curves of logMW vs. elution volume, Ve, were constructed for each column using the integral-MWD method as described previously (9). Molecular weight distributions of absorbed material were determined from the calibration curves and the sample s chromatograph by curve summation (9). 

Now the function displays the number fraction of molecules with a certain molecular mass. Its integral is 1 by definition. Nevertheless, we still call it the number molecular weight distribution because the factor /N (A/) dM is nothing but a constant. 

Specialty calculations for gel permeation chromatography (GPC) where the integrator would calculate the molecular weight distribution, molecular weight average, and polynomial curves for calibration. 

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