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Rheological properties of polymer solutions

In 1934 Kuhn (56] sought to combine the statistics of flexible polymer chains with Einstein s formulation. He showed that from random flight statistics (57] that the mean square end-to-end distance and essentially the diameter of the equivalent sphere (radius of gyration 5 ) of the polymer chain (57] was [Pg.118]

The volumes of polymer chains in a dilute solution are representable through [Pg.119]

Experimentally it is foimd [rj] increases more slowly with molecular weight than predicted by Staudinger [50] and more rapidly than predicted by Kuhn [56]. It is now generally expressed [Pg.119]

The concentration dependence of the viscosity of polymer solutions over wide ranges of concentration has been investigated by various researchers since the 1950s [58 to 66]. Johnson et al. [58] found the low shear viscosity i] of polyisobutylene solutions to increase with the fifth power of concentration. Ide and White [66] describe similar behavior with polystyrene solutions (see Fig. 3.8). [Pg.119]

Onogi et al. [63] in a 1967 paper describe a broader perspective where they represent t) by [Pg.119]

The rheology of a polymer solution increases with the polymer concentration. A transition exists at the so-called critical concentration (which decreases with increasing molecular mass) separating dilute from concentrated solutions. [Pg.599]

The viscosity of dilute polymer solutions can be estimated with fair accuracy. [Pg.599]

For concentrated polymer solutions the viscosity is proportional to the 3.4th power of the molecular mass and about the 5th power of the concentration. The effects of temperature and concentration on viscoelastic properties are closely interrelated. The validity of a time-concentration superposition is shown. A method is given for predicting the viscosity of concentrated polymer solutions. [Pg.599]

The rheology of polymer solutions is a subject of considerable practical interest. It is important in several stages of the manufacturing and processing of polymers, e.g. in the spinning of fibres and the casting of films from solutions, and especially in the paints and coatings industry. [Pg.599]

Despite the large amount of literature on this subject, the rheology of polymer solutions is less completely understood than that of polymer melts. This is because two more parameters are involved the nature and the concentration of the solvent. [Pg.599]


Philippoff, W., Gaskins,F.H., Brodnyan, J.G. Flow birefringence and stress. V. Correlation of recoverable shear strains with other rheological properties of polymer solutions. J. Appl. Phys. 28,1118-1123 (1957). [Pg.178]

From the above results together with those of other investigators who used distilled water as a solvent [98, 99], it can be concluded that the rheological properties of polymer solutions may be modified by changing the chemistry of the solvent. It follows that the hydrodynamic and heat transfer performance is sensitive to solvent chemistry. [Pg.773]

The major emphasis in this chapter is on the first three items—the chemical and/or binding interactions of polymers to hair the chemical nature of hairsprays, setting products, and mousses and the in situ polymerization reactions in hair. Although the rheological properties of polymer solutions are especially important to formula viscosity and to the sensory perceptions of cosmetics, they will not be emphasized here. It suffices to say that cellu-losic ethers [8, 9] are probably the most important thickening agents in hair products, and ethoxylated esters and carboxy vinyl polymers are also important. [Pg.346]

The rheological properties of polymer solutions are remarkably similar to those of polymers in the undiluted state parameters such as molar mass, temperature, and... [Pg.353]

The rheological properties of polymer solutions play an important role in determining their effectiveness. Depending on the process, polymers can encounter various chemical species, such as simple salts, alkalis, and surfactants. The presence of these chemicals together may significantly alter the chemical and physical nature of the polymer molecules and, consequently, the viscosity of the polymer solution will change. [Pg.616]

The relationship between polymer structure and the rheological properties of polymer solutions is very wide and complex. This brief account is simply intended to indicate that the observed differences between the rheological behaviour of polyacrylamide and xanthan are based on their molecular structures. Although these two polymers may be superseded by improved polymers, both synthetics and biopolymers, as discussed in Chapter 2, the... [Pg.65]

In this chapter, we have discussed some basic rheological properties of polymer solution flow in porous media, such as rheological terms, shear rate models, experiment... [Pg.200]

Y. Isono and M. Nagasawa. Solvent effects on rheological properties of polymer solutions. Macromolecules, 13 (1980), 862-867. [Pg.396]


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