Stress-optical rule relaxation

Here, 0 is the nematic coupling constant between the monomeric segments of the components. From Equation (3.57), we note that of the short-chain component does not fully relax even in the range of co where its modulus Gi (co) has fully relaxed but the modulus G2 ((o) of the long-chain component remains unrelaxed. This theoretical prediction is consistent with experiments. We can also confirm that Equations (3.56) and (3.57) give K (co) = Ki (co) + K2 (o) = C G/((o) + G2 (co) and are consistent with the stress-optical rule. Equation (3.53). 

The stress optical law is maintained during relaxation of a deformed rubber (Figure 6.17) (Balasubramanian et al., 2005) moreover, the same proportionality to An is maintained for the normal components of the stress. And since orientation of rubber also affects heat conduction (Hands, 1980), there is a corresponding proportionality, known as the stress-thermal rule, between sttess and the anisotropy of the thermal conductivity (Venerus et al., 1999) ... 

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