Rheological models Ellis

There are numerous other GNF models, such as the Casson model (used in food rheology), the Ellis, the Powell-Eyring model, and the Reiner-Pillippoff model. These are reviewed in the literature. In Appendix A we list the parameters of the Power Law, the Carreau, and the Cross constitutive equations for common polymers evaluated using oscillatory and capillary flow viscometry. 

For the investigated emulsions, i oo tio Under this condition, the Peeck-Mak-Lean-Williamson equation transforms into the Ferry equation and, therefore, is not suitable for description of the viscosity of extracting emulsions. In the Meter equation, the term (P/Pav) ( oo/T o) approaches 1 at Tjoo i1o- Thus, Equation 8 is transformed into the Ellis equation. Values of P1/2 and the exponential coefficient A for the Ellis model are presented in Figure 8. It should be noted that the value for A is constant and equal to 6 in the equation which describes the rheological curves of the extracting emulsions for the indicated range of dispersed phase content. 

Table 6.6 Rheological Parameters of the Modified Ellis Model [Eq. (6.2)] for Different Generic-Type Thermoplastics...

Tables 6.S-6.8 list the model constants and the range of applicability based on the modified Carreau model, the modified Ellis model, the modified Ostwald-de Waele power-law model, and the General Rheological [11] model, respectively, for the master rheograms of most of the polymers discussed in Chapter 4.

Table 2 also shows rheological parameters obtained by fitting the experimental data of dynamic viscosity vs. frequency to an Ellis model [9]. The viscosity extrapolated to zero frequency values can be considered proportional to the weight average molecular weight of the polymers. Indeed, the values are inversely proportional to the MFI values reported in Table 1. cot is the frequency onset at which pseudoplastic effects start... 

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