Viscosity vs. molecular weight

The intrinsic viscosity vs molecular weight dependence extracted from the SEC experiments curve of the intrinsic viscosity also often gives a straight line in the double logarithmic plot and can be described by the (KMHS) relationship ... 

A large number of papers has dealt with the question of molecular weight and molecular weight distribution in polyacrylonitrile. Recent discussions are those of Onyon 108), Krigbaum and Kotliar 90), Booth and Beason 33), Bamford, Jenkins, Johnston and White 19) and Kobayashi 87). The intrinsic viscosity vs. molecular weight relationship of Cleland and Stockmayer 41) is probably as well supported as any. Fortunately, much of the material in this review does not depend heavily on detailed knowledge of molecular weights or of their distributions. 

Fig. 15.27. Viscosity vs. molecular weight. (Harper, Charles A., Modern Plestics Handbook, p. 5.13, Copyright 2000 by The McGraw-Hill Companies and used with permission of the copyright owner.)...

Well defined break in the zero-shear vs. molecular weight relationship No break in the zero-shear viscosity vs. molecular weight relationship... 

Figure 1.4 Graph of melt shear viscosity vs. molecular weight...

Figure 9.6 Zero-shear viscosity vs. molecular weight of nearly monodisperse 1,4-polybutadienes at T=25°C for (a) linear molecules A Struglinski and Graessiey [29] Roovers [30, 31] Rubinstein and Colby [32] Baumgaertel etal. [33] and for (b) stars Raju etal. [34] Roovers [30] A Roovers [31 ] Struglinski, et al. [35]. The solid line is the prediction of the Milner-McLelsh theory using a = 1 with = 9.5 -JO" s,M = 2200 and the dashed line using a = 4/3 = 3.7...

Figure 4 Intrinsic viscosity vs. molecular weight M for polystyrene in toluene (O) at 2CC and THF (A) at 25 °C (reproduced by permission of the American Chemical Society from Macromolecules, 1979, 12, 968)...

It was shown that the logarithm of the product of intrinsic viscosity and molecular weight of polymers of different chemical and stereochemical composition, configuration, or molecular weight is linearly related to the elution volume.81 A plot of log (r) M) vs. elution volume provides a single calibration curve, useful for samples of similar composition, and is termed a universal... 

Grubisic et al. (3) showed that for many polymers a single calibration curve can be drawn through a plot of the product of intrinsic viscosity and molecular weight ( [7/] M) vs. retention volume. This relationship certainly supports the model of molecular separation based on hydro-dynamic volume since [77] M is proportional to the hydrodynamic volume of the molecule in solution. Hence, molecular weights of the two polymers (calibration standard polymer and sample) which have identical retention volume under identical GPC analytical conditions can be expressed in terms of each other by combining the Grubisic relationship ... 

Figure 1. Disagreement between viscometric and GPC viscosity-average molecular weight vs. weight percent of the sample component with retention volume less than the highest molecular weight calibration standard...

Fig. 4 Ultimate Tensile Strength vs. molecular weights of PVC samples predicted from relative viscosity measurements for Occidental Chemical Co. experimental products.

Figure I. Poly(vinyl chloride) resin general performance /property characteristics vs. molecular weight. Molecular weight was evaluated by intrinsic viscosity (ASTM D-1243-A).

This brings us to the relationship between the intrinsic viscosity and molecular weight This was first established empirically from plots of log r vs log Mol Wr., which were found to be linear (Figure 12-29), meaning that the relationship between the two quantities has the form (Equation 12-47) ... 

Pig. 10. Double logarithmic plot of diffusion coeffF cient D (1) and intrinsic viscosity [q J (2) vs. molecular weight Mfot poly(p-phenylene-l,3,4-oxadia-zole) samples in sulfuric acid ). Curves 1 and 2 are theoretical curves ... 

The equation with pertinent constants for polychloroprene is used in determining the extent of branching. Thus, several linear polymers were made vmder extreme control conditions. The molecular weight distribution and intrinsic viscosities were determined for each polymer. A plot of In IV) vs molecular weight yielded a and If values ... 

Fig. 18. Double logarithmic representation of the viscosity vs scaled molecular weight for a series of polymers, showing the change from a weak (nearly linear) dependence of viscosity on molecular weight to the entangled regime where rjo a After Berry and Fox (57), with permission.

From a Mark-Houwink plot of intrinsic viscosities V5. molecular weight, [see Section 3.8.3 and equation (3.97)], values of K and a were estimated at 10 cm7g and 0.7, respectively (63). The dependence of the solution viscosity vs. concentration resembles that of ordinary polymer solutions. 

FIG. 6 Zero-shear rate viscosity tjq vs. molecular weight M, obtained from the MD simulation and the Rouse model for small M (circles) or the reptation model for high M (squares). Also shown in the figure are experimentally obtained rjo values (triangles). 

Mark-Houwink Equation n Also referred to as Kuhn-Mark-Houwink-Sakurada equation allows prediction of the viscosity average molecular weight M for a specific polymer in a dilute solution of solvent by [77] = KM where K is a constant for the respective material and a is a branching coefficient K and a (sometimes a ) can be determined by a plot of log [r ] vs. log and the slope is a and intercept on the Y axis is K. (Kamide K, Dobashi T (2000) Physical chemistry j / of polymer solutions. Elsevier, New York Physical properties of polymers handbook. Mark JE (ed). Springer,... 

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