Of polymeric liquids

Mate C M, Lorenz M R and Novotny V J 1989 Atomic force microscopy of polymeric liquid films J. Chem. Phys. 90... 

Similar relations for other non-Newtouiau fluids may be found in Govier and Aziz and in Bird, Armstrong, and Hassager (Dynamics of Polymeric Liquids, vol. 1 Fluid Mechanics, Wiley, New York, 1977). 

For laminar flow of power law fluids in channels of noncircular cross section, see Schecter AIChE J., 7, 445 48 [1961]), Wheeler and Wissler (AJChE J., 11, 207-212 [1965]), Bird, Armstrong, and Hassager Dynamics of Polymeric Liquids, vol. 1 Fluid Mechanics, Wiley, New York, 1977), and Skelland Non-Newtonian Flow and Heat Transfer, Wiley, New York, 1967). 

Bird RB, Curtiss CF, Armstrong RC, Hassager O (1987) Dynamics of polymeric liquids, 2nd (edn) John Wiley, New York, vol 2, p 58... 

Since the earliest discoveries of polymeric liquid crystalline melts and solutions a large number of such systems have been reported and this continues to be a vigorous field of research. 

Different molecular theories have been established [27-32] to describe the viscoelasticity of polymeric liquids. Due to their importance, a brief survey of the different theories will be given below. 

In most cases polymer solutions are not ideally dilute. In fact they exhibit pronounced intermolecular interactions. First approaches dealing with this phenomenon date back to Bueche [35]. Proceeding from the fundamental work of Debye [36] he was able to show that below a critical molar mass Mw the zero-shear viscosity is directly proportional to Mw whereas above this critical value r 0 is found to be proportional to (Mw3,4) [37,38]. This enhanced drag has been attributed to intermolecular couplings. Ferry and co-workers [39] reported that the dynamic behaviour of polymeric liquids is strongly influenced by coupling points. 

Non-linear viscoelastic flow phenomena are one of the most characteristic features of polymeric liquids. A matter of very emphasised interest is the first normal stress difference. It is a well-accepted fact that the first normal stress difference Nj is similar to G, a measure of the amount of energy which can be stored reversibly in a viscoelastic fluid, whereas t12 is considered as the portion that is dissipated as viscous flow [49-51]. For concentrated solutions Lodge s theory [52] of an elastic network also predicts normal stresses, which should be associated with the entanglement density. 

See for example Tirrell, M., Rheology of polymeric liquids , Chapter 11 in Macosco,... 

The step-strain experiments discussed above furnish the simplest example of a strong flow. Many other flows are of experimental importance transient and steady shear, transient extensional flow and reversing step strains, to give a few examples. Indeed the development of phenomenological constitutive equations to systematise the wealth of behaviour of polymeric liquids in general flows has been something of an industry over the past 40 years [9]. It is important to note that it is not possible to derive a constitutive equation from the tube model in... 

An important advance in ion-selective electrodes (ISEs) and related systems was based on the concept of polymeric liquid membranes developed by Eisenman [122]. The principle of this approach was to incorporate an organic compound as the ionophore into a polyvinyl chloride membrane... 

The influence of the bonded organic moiety on solute retention has not yet been elucidated and only a very small number of papers discuss the properties and use of such phases so far. The numerous advantages of chemically bonded phases make the application of polar chemically bonded phases with nonpolar eluents quite attractive even if the standardization of these phases may pose problems 106) similar to those encountered in the standardization of aidsorbents as well as of polymeric liquid phases in gas chromatography. A detailed discussion of the properties and chromatographic use of bonded stationary phases is given by Melander and Horvath (this volume). 

Source (1) Bird, R. B., W. E. Stewart, and E. N. Lightfoot, Transport Phenomena, John Wiley Sons, New York, I960., (2) Dynamics of Polymeric Liquids, Bird, R. B., R. C. Armstrong, and O. Hassager, Vol. 1, John Wiley Sons, New York, 1977., (3) Johnson, A. T., Biological Process Engineering, Wiley-Interscience, New York, 1999. 

Source Adapted from Dynamics of Polymeric Liquids g/ mo 01 T louBxoqopAo-uqnoap x T niFoaQ sj3MSuy... 

Dynamics of Polymeric Liquids, Bird, R. B., R. C. Armstrong, and O. Hassager, Vol. 1, John Wiley Sons, New York, 1977. 

A sliding plate rheometer (simple shear) can be used to study the response of polymeric liquids to extension-like deformations involving larger strains and strain rates than can be employed in most uniaxial extensional measurements (56,200—204). The technique requires knowledge of both shear stress and the first normal stress difference, (7), but has considerable potential for characterizing extensional behavior under conditions closely related to those in industrial processes. 

Bird, R.B., Armstrong, R.C., Hassager, O. Dynamics of Polymeric Liquids Volume 1—Resin Mechanics, 2nd ed. (1987) John Wiley Sons, New York... 

Pure polyvinyl chloride alone It a rigid plastic of high volume resistivity. Addition of monomeric liquid plasticizer makes It flexible but lowers volume resistivity seriously. This loss of volume resistivity was not prevented by pre-purification of commercial resin and plasticizer, though It could be worsened by addition of Ionic soluble Impurities. Volume resistivity was surprisingly Increased by heat aging. It was not improved by use of polymeric liquid plasticizers, nor even, surprisingly, by use of nitrile rubber as plasticizer. Flexlblllzatlon without serious loss of volume resistivity was best achieved by internal plasticization by copolymerization with 2-ethylhexyl acrylate. Further studies are needed to explain these observations and to optimize the use of Internal plasticization In this way. 

It is now generally accepted that the viscous flow of polymeric liquids is connected with chain segment rotation, i.e. with configurational entropy. From this point of view Miller concluded that the Simha-Boyer equation was not correct since the relative free-volume in SB theory equals zero at 0 K, not at T = T0. If the latter... 

Scientists and engineers experienced in the production and application of polymeric liquids have learned from thousands of examples of how polymeric liquids behave, and can even classify some of them into behavioral families. But the complexity of these substances to date has eluded the achievement of precise designs and predictive behavior. 

Blumstein, R. B. and Stickles, E. Influence of molecular weight on some properties of polymeric liquid crystals. Proc. 28th Macromol. Symp. IUPAC, U. Mass., Amherst, MA, p. 799, 1982... 

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