| Abstract: | The principal polarizabilities of rubber molecules including copolymers were evaluated by the arithmetic sum of the polarizabilities of the components. The mean polarizabilities thus calculated are in good accordance with those from the refractive indices. The anisotropic polarizabilities of polymeric units for several kinds of rubbers were calculated and compared with those estimated from stress-optical coefficients. Length or molecular weight of a statistical link thus estimated is used as a measure of stiffness of rubber molecules. There is a good accordance in statistical links between anisotropic and viscosity measurements in theta solvent. The molecular weight or length of a statistical link thus obtained is found to be compatible with the value calculated from end-to-end distance in theta solvent. The ultimate elongation of rubber is correlated with the stiffness and can be estimated from the measure of stiffness of the chain. |
