Polymeric liquids dynamics

The KSR and Rouse models were subj ected to numerous experimental tests. A reasonably good agreement between the theoretical predictions and experimental data was demonstrated for a variety of dilute polymeric solutions. Further advance in the molecular-kinetic approach to description of relaxation processes in polymeric systems have brought about more sophisticated models. They improve the classical results by taking into account additional factors and/or considering diverse frequency, temperature, and concentration ranges, etc. For the aims of computer simulation of the polymeric liquid dynamics in hydrodynamic problems, either simple approximations of the spectrum, Fi(A), or the model of subchains are usually used. Spriggs law is the most used approximation... 

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... 

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. 

Some years ago, on the basis of the excluded-volume interaction of chains, Hess [49] presented a generalized Rouse model in order to treat consistently the dynamics of entangled polymeric liquids. The theory treats a generalized Langevin equation where the entanglement friction function appears as a kernel... 

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. 

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

In a majority of works on LC polymers, the main attention was paid to the synthesis and structural studies of such polymers. Significantly less information is available on physical properties of LC polymers, especially, when compared to low-molecular liquid crystals. In this chapter some rheological and dielectric properties of polymeric liquid crystals, characteristics of their dynamic properties and intramolecular mobility, are considered. 

Early work on the use of optical methods on the dynamics of polymeric liquids focused on establishing the validity of the stress-optical rule. A comprehensive account of this research can be found in the books by Janeschitz-Kriegl [29] and Wales [84], The majority of studies have considered simple shear flow, and the rule has been found to hold up to... 

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