Rubberlike elasticity, molecular basis

B. Erman and J.E. Mark, The molecular basis of rubberlike elasticity. In J.E. Mark, B. Erman and... 

It can seen from Figure 5.4 that the equilibrium compliance Je decreases uniformly from the 1007/DDS to the 828/DDS and is expected on the basis of the kinetic theory of rubberlike elasticity, since the concentration of network chains increases and the molecular weight per crosslinked unit, Mx, decreases in the same order. The Mx values calculated as /o/JT/g are remarkably close to the molecular weight values of the starting epoxy resins. 

The Molecular Basis of Rubberlike Elasticity TABLE I Some Typical Values for f, /f... 

These deductions from basic facts of observation interpreted according to the rigorous laws of thermodynamics do not alone offer an insight into the structural mechanism of rubber elasticity. Supplemented by cautious exercise of intuition in regard to the molecular nature of rubberlike materials, however, they provide a sound basis from which to proceed toward the elucidation of the elasticity mechanism. The gap between the cold logic of thermodynamics applied to the thermoelastic behavior of rubber and the implications of its... 

Muller investigated the relationship between the molecular orientation and the mechanical and optical anisotropies in fibrous as well as crosslinked rubberlike materials. The mechanical and optical properties of a crosslinked rubber network under deformation were theoretically analyzed with the so-called freely jointed equivalent chain model by Kuhn and Griin" and Treloar." Mechanical anisotropy in preoriented crystalline polymers was discussed by Raumann" " and by Ward et on the basis of the infinitesimal anisotropic elastic theory. Ward also expressed the... 

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