Mooney-Rivlin constants from

In order to check this prediction, stress-strain measurements were made up to moderate strains at room temperature. The obtained data are plotted in the usual manner as a versus 1/X in Figure 8. Table V gives the Mooney-Rivlin constants 2C and 2C calculated from these plots and also the ratio C./Cj. 

Mooney-Rivlin constants obtained from strain dependent measurements at 298 K... 

The phantom network behaviour corresponding to volumeless chains which can freely interpenetrate one through the other and thus to unrestricted fluctuations of crosslinks should be approached in swollen systems or at high strains (proportionality to the Mooney-Rivlin constant C-j). For suppressed fluctuations of crosslinks, which then are displaced affinely with the strain, A for the small-strain modulus (equal to C1+C2) approaches unity. This situation should be characteristic of bulk systems. The constraints arising from interchain interactions important at low strains should be reflected in an increase of Aabove the phantom value and no extra Gee contribution to the modulus is necessary. The upper limit of the predicted equilibrium modulus corresponds therefore, A = 1. 

In many cases it is reasonable to take the initial value of [f ]ph = 2Ci, where 2Ci is the first Mooney-Rivlin constant. An alternative possibility is to estimate [f ]ph from the stoichiometry of the chemical reaction using Eqs. (29.12)-(29.14) and (29.41). 

Specimen MJIO (glmol) (LALLS) (glmol) (GPC) V from Mooney-Rivlin constant (10 moljg) V from equilibrium swelling (10 moljg)... 

C0 and Ci can be determined with at least two independent measurements. The constant Q is obviously different from WLF or Mooney-Rivlin equations (Chapter 11). 

TABLE 13.7 Constants of the Mooney-Rivlin equation (numerical values derived from Blokland (1968))... 

Solution cross-linked elastomers also exhibit stress-strain isotherms in elongation that are closer in form to those expected from the simplest molecular theories of rubberlike elasticity. Specifically, there are large decreases in the Mooney-Rivlin 2C correction constant described in... 

It is interesting to compare eq. (3.54) with the expressions obtained from the statistical theories (Fig. 3.20). According to both the affine network model and the phantom network model of James and Guth, the reduced stress remains constant and independent of strain, which is not the case for the Mooney-Rivlin equation. 

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