FINITE EXTENSIBILITY EFFECTS IN NEMATIC ELASTOMERS

We present a model calculation of the elasticity of a nematic elastome r of finite-length network strands under affine deformation. The resul t is derived in its full tensorial structure, and its predictions are examined. In particular, we look at the non-Gaussian corrections to th e effects of soft elasticity and elastic anisotropy. We find that the soft modes can at most be hardened at O(N-2) when compared to the conv entional rubber elastic energy, where N is the number of monomer units along a typical strand. The elastic moduli for extensions parallel an d perpendicular to the nematic director are found to differ at O(N-1). (C) 1998 American Institute of Physics. [S0021-9606(98)50820-3].