Networks with semi-flexible chains

Classical theories of rubber elasticity are based on the statistical behavior of flexible Gaussian chains with a characteristic ratio of the order of unity. The elasticity of the network is primarily of intramolecular origin arising from the entropy of the individual chains. Intermolecular contributions are of secondary importance. The present communication is based on an alternate description of networks with semi-flexible chains in which the competition for space among neighboring chains are represented according to a lattice model. The model which constitutes the basis of the following work, indicates that intermolecular effects on the chain segments. Accordingly, an with increasing asymmetry of the chain segments. Accordingly, an abrupt change in the orientation function indicating a first order transition from a relatively disordered to a highly ordered phase occurs upon stretching of network chains, provided that the length-to-width ratio of the Kuhn segments exceeds a critical value. Also, calculations indicate that the critical conditions are more readily attained in the presence of thermotropic interactions.