Intrinsic viscosity-molecular weight relation

S 5 Sato, H., and T. Yamamoto Intrinsic viscosity molecular weight relation for poly-2-methyI-5- vinylpyridine (in Methanol und Dimethylformamid). Nippon Kagaku Zashi 80, 1393 (1959). 

N, indicating that the solvent quality is substantially reduced by addition of salt, as in Wallach s study. If the extrapolation to M = 0 is not sufficient to eliminate all excluded volume contribution, then the estimated unperturbed dimensions could be affected. The samples used in reference 3 were also of varying polydispersity, and the intrinsic viscosity molecular weight relation showed more uncertainty than we have observed in this study, which is also sufficient to explain the difference in estimated unperturbed chain dimensions. 

RED Reddy, C.R. and Kalpagam, V., Dilute solution properties of styrene-acrylonitrile and styrene-methyl methacrylate copolymers. 1. Intrinsic viscosity-molecular weight relations, J. Polym. Sci. Polym. Phys. Ed., 14, 749, 1976. 

Fig. 1-8 Intrinsic viscosity-molecular weight relations for polyisobutylene [13-15].

FIGURE 5.5 Intrinsic viscosity-molecular weight relations for polyisobutylene in cyclohexane at 30 °C and diisobutylene at 20 °C. Reprinted from RJ. Flsory, Principles of Polymer Chemistry. Copyright 1953 by Cornell University. Used by permission of Cornell University Press. 

Intrinsic viscosity molecular weight relationship. The values of two constants appearing in the above relation, determined when fractions of a polymer of molecular weights 34000, 61000 and 130000 dissolved in an organic solvent gave the intrinsic viscosities as 1.02,1.60 and 2.75 respectively at 25°C... 

Intrinsic Viscosity—Molecular Weight Relationship for PMMA in TFE. The intrinsic viscosities of the PMMA preparative GPC fractions and whole polymers in TFE at 50 °C and in benzene at 30 °C are shown in Table III and plotted in Figure 4. A least-squares analysis of the data plotted in Figure 4 yields the relation... 

The molecular weight is normally measured, for convenience sake, by solution viscosity and is often given as the intrinsic viscosity. There is a wide range of solutions used, with the average molecular weight related to the intrinsic viscosity by the Mark-Houwink equation ... 

Accordingly, if we assume that Vh is proportional to V, then the intrinsic viscosity should be related to the molecular weight by Equation 12-55 ... 

If the polymer is polydisperse, the intrinsic viscosity is obviously related to some kind of average molecular weight, appropriately called the viscosity average by Flory (1943), which depends on the magnitude of o. It is a common practice to define the different averages of molecular weight by the general relationship ... 

At the theta temperature, the intrinsic viscosity [17] is related to the unperturbed dimension of the polymer and its molecular weight [1] by... 

Solubility parameters can also be estimated from intrinsic viscosity. Flory [101] related intrinsic viscosity to polymer molecular weight and the chain-expansion factor. The chain-expansion factor can, in turn, be related to the polymer-solvent interaction parameter using the Flory-Hug-gins theory. A variety of models can be used to relate the interaction parameter to solubility parameters [87,102,103] these equations have the form... 

Both intrinsic viscosities can be related to molecular weight by using the Mark-Houwink equation. 

Thus, according to this theory, at a given molecular weight, the intrinsic viscosity [r]] is related to N by the frictional coefficient / of a monomer unit and the effective bond length b of the chain. As N approaches infinity, [rj] becomes independent of / and the above equation may be simplified to... 

The intrinsic viscosity (IV) is related to the molecular weight of the polymer through the Mark-Houwink relationship [3]. The technique used to perform IV measurements is described in ASTM D2857 and D4020. A Ubbelohde No. 1 viscometer, as shown in Figure 24.7, is placed in an oil bath at 135°C. The polymer powder is... 

At first glance, the contents of Chap. 9 read like a catchall for unrelated topics. In it we examine the intrinsic viscosity of polymer solutions, the diffusion coefficient, the sedimentation coefficient, sedimentation equilibrium, and gel permeation chromatography. While all of these techniques can be related in one way or another to the molecular weight of the polymer, the more fundamental unifying principle which connects these topics is their common dependence on the spatial extension of the molecules. The radius of gyration is the parameter of interest in this context, and the intrinsic viscosity in particular can be interpreted to give a value for this important quantity. The experimental techniques discussed in Chap. 9 have been used extensively in the study of biopolymers. 

Experiments based on the Poiseuille equation make intrinsic viscosity an easily measured parameter to characterize a polymer. In the next section we consider how this property can be related to the molecular weight of a polymer. 

Molecular Weight. The molecular weight of polypropylene is typically determined by viscosity measurements. The intrinsic viscosity [Tj] of the polymer in solution is related to the molecular weight, Af, by the Matk-Houwink equation ... 

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