Society of Rheology

Viscosity is equal to the slope of the flow curve, Tf = dr/dj. The quantity r/y is the viscosity Tj for a Newtonian Hquid and the apparent viscosity Tj for a non-Newtonian Hquid. The kinematic viscosity is the viscosity coefficient divided by the density, ly = tj/p. The fluidity is the reciprocal of the viscosity, (j) = 1/rj. The common units for viscosity, dyne seconds per square centimeter ((dyn-s)/cm ) or grams per centimeter second ((g/(cm-s)), called poise, which is usually expressed as centipoise (cP), have been replaced by the SI units of pascal seconds, ie, Pa-s and mPa-s, where 1 mPa-s = 1 cP. In the same manner the shear stress units of dynes per square centimeter, dyn/cmhave been replaced by Pascals, where 10 dyn/cm = 1 Pa, and newtons per square meter, where 1 N/m = 1 Pa. Shear rate is AH/AX, or length /time/length, so that values are given as per second (s ) in both systems. The SI units for kinematic viscosity are square centimeters per second, cm /s, ie, Stokes (St), and square millimeters per second, mm /s, ie, centistokes (cSt). Information is available for the official Society of Rheology nomenclature and units for a wide range of rheological parameters (11). 

Figure 16 Tube model for reptation of a branched polymer molecule from the work of Blackwell et al. [124]. Reproduced with permission from Blackwell et al. [124]. Copyright 2000, The Society of Rheology, Inc.

Nomenclature, 17 384-413 basic scheme of, 17 384-385 biochemical, 17 401-402 computerized approaches to, 17 400-401 elastomer, 21 761t enzyme, 10 258-260 for ionic liquids, 26 840-841 glossaries related to, 17 404 inorganic, 17 387-394 macromolecular (polymers), 17 403 404 organic, 17 394-401 polymer, 20 390-395 pump, 21 88 quinone, 21 236-237 reactor technology, 21 358 related to mass transfer, 15 731-737 reverse osmosis, 21 674-676 Society of Rheology, 21 704 spray-related, 23 199t systematic, 17 394... 

Society of Flavor Chemists, Inc., 11 563 Society of Rheology nomenclature, 21 704 Society of the Plastics Industry, The (SPI) on PVC recycling, 25 680 recycling coding system of, 25 681 Sociopolitical dimensions, of sustainable development, 24 189—190 Socks (mid-calf)... 

Chou, D. Richert, S. H. Golden Jubilee Meeting, Society of Rheology, Nov. 1979, Boston, MA. paper 32-3. 

Kramer, O., Carpenter, R. L., Ty, V., Ferry, J. D. Entanglement networks crosslinked in states of strain, paper presented at Society of Rheology Meeting, Montreal, October 1973. Part of this work is described in Entanglement networks of 1,2-poly butadiene crosslinked in states of strain. I. Cross-linking at 0° C. Macromolecules 7,79-84 (1974), by the same authors. 

J.L. Kokini and T.K. Chou, The Phenomenon of Slip in the Steady Shear Capillary Flow of Four Semi-solid Foods, presented at the Winter Meeting of the Society of Rheology, Santa Monica, California, January 18-21,1987. 

P. V. Danckwerts, Theory of Mixtures and Mixing, Research (London), 6, 355-361 (1953) see also P. V. Danckwerts, General Aspects of Mixtures and Mixing, paper presented at the Symposium on Mixing of Thick Liquids, Pastes, and Slurries, British Society of Rheology, London, September 1953 cf. N. Wookey, Mixing of Thick Liquids, Pastes and Slurries , Nature, 172, 846-847 (1953). 

The symbols used follow the recent recommendations of the Society of Rheology SI units are used. We follow the stress tensor convention used by Bird et al., namely, n = P6 + x, where n is the total stress tensor, P is the pressure, and x is that part of the stress tensor that vanishes when no flow occurs both P and x, are positive under compression. 

FIG. 15.23 Extensional rheometer, designed by Miinstedt (1979). A servo control system is used to maintain a specified extensional rate of strain or a specified tensile stress. Courtesy Society of Rheology. For a modern version, see Miinstedt et al., 1998. 

FIG. 15.33 Extrudate swell ratio as a function of L/Da for high-density polyethylene at 18 °C for shear rates as indicated. From Han et al. (1970). Courtesy Society of Rheology. 

FIG. 15.37 Extrudate swell ratio vs. shear stress at the wall, for melts of polystyrenes of broad and narrow molecular-weight distributions. Filled symbols the broad polystyrene mentioned in Fig. 15.34-15.36 Mw = 2.2 x 105 and Mw/Mn = 3.1. Open symbols narrow polystyrene Mw = 1.6 x 105 and M /Mn < 1.1. From Greassley et al. (1970). Courtesy Society of Rheology. 

FIG. 15.46 Viscosity, 77, and first normal stress difference, Nh of Vectra 900 at 310 °C as functions of shear rate, according to Langelaan and Gotsis (1996). The first normal stress coefficient, Yi, is estimated from N, by the present author. ( ) Capillary rheometer ( ) and ( ) cone and plate rheometer ( ) complex viscosity rj (A) non-steady state values of the cone and plate rheometer. Courtesy Society of Rheology. 

FIG. 16.16 Shear rate dependence of viscosity as a function of concentration. Data were obtained on a single narrow molecular weight distribution of polystyrene (Mw = 411 kg/mol) in n-butyl benzene at 30 °C. From Graessley, Hazleton and Lindeman (1967). Courtesy Society of Rheology. 

FIG. 16.18 Non-Newtonian viscosity ratio for solutions of narrow molecular weight distribution polystyrenes in n-butyl benzene, plotted vs. reduced shear rate q/q0, where qa, equal to the reciprocal of the characteristic time constant Tn, is chosen empirically for each solution. The data were obtained for molecular weights ranging from 160 to 2400 kg/mol and for concentrations ranging from 0.255 to 0.55 g/ml at temperatures from 30 to 60 °C.The full line is calculated with the aid of Eqs. (16.52)—(16.55). From Graessley, Hazleton and Lindeman (1967). Courtesy Society of Rheology. 

Walters K and Jones DM, in Uhlherr PHT (Ed) "Proceedings of the 10th International Congress on Rheology", Vol. 1, Australian Society of Rheology, 1988, pp 103-109 Rheol Acta 28 (1989) 482. 

Shear Rate, denoted by the symbol, j>, is the velocity gradient established in a fluid as a result of an applied shear stress. It is expressed in units of reciprocal seconds, s". Shear Stress is the stress component applied tangentially. It is equal to the force vector (a vector has both magnitude and direction) divided by the area of application and is expressed in units of force per unit area (Pa). The nomenclature committee of the Society of Rheology recommends that the symbol a be used to denote shear stress. However, the symbol r that was used to denote shear stress for a long time can be still encountered in rheology literature. 

Doi M, Edwards SF (1986). The Theory of Polymer Dynamics, Oxford Press, New York. Dratler Dl, Schowalter WR, Hottman RL (1997). Presentation at the 68th Annual Meeting of the Society of Rheology, Galveston, TX. 

The American Society of Rheology, which was founded in 1929, has defined rheology as the science of deformation and flow of matter. Deformation describes the change of matter in terms of shape or volume, or both. If the changes due to deformation are at least partly nonreversible, then matter flows. The full spectrum of possible types of deformation of liquid or solid matter is illustrated in Fig. 1. The gaseous state is usually not part of rheological investigations. 

Beris, A.N. Dimitropoulos, C.D. Sureshkumar, R. Handler, R.D. Direct numerical simulations of polymer-induced drag reduction in viscoelastic turbulent channel flows. Proceedings of the International Congress on Rheology, Cambridge, U.K., Aug 20-25 British Society of Rheology Glasgow, 2000 Vol. 2, 190-192. 

J. Zhou, G. Metcalfe, L. Graham, and R. Hamilton, Proc. Int. Congr. Rheol 13th, 2000,2, 297-299, ed. D. M. Binding, British Society of Rheology, Glasgow, UK. 

Sadowski, T.J., Bird, R.B., 1965. Non-Newtonian flow through porous media. I. theoretical. Transaction of the Society of Rheology (Trans. Soc. Rheol.) 9 (2), 243—250. 

Seright, R.S., Adamski, R.P., Roffall, J.C., Liauh, W.W., 1983. Rheology and mechanical degradation of EOR polymers. Paper presented at die SPE/British Society of Rheology Conference on Rheology in Crude Oil Production, Imperial College, 13—15 April. 

Stroeve, P., Prabodh, P.V., l.lias, T. and Ulbrecht, JJ. (1981). Stability of double emulsion droplets in shear flow. In 53rd Annual Meeting of the Society of Rheology, Louisville, KY, October, 11-15. 

Kotaka, T., Kojima, A., Kubo, H., and Okamoto, M., Society of Rheology Annual Meeting, Texas, 1997. 

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