Abstract
The orientational order parameters of MBBA from two sources (clearing temperatures 317.5° and 318.9°K) as functions of temperature were obtained from optical anisotropy (birefringence) measurements of orientated thin films by a variable wave-length method. The formula proposed by Vuks for the polarization field associated with strongly anisotropic organic molecules was used as the basis for the development of new expressions used in our evaluation of the order parameter. The order parameters versus temperature reported in this paper are in very good agreement with recent NMR and Raman scattering measurements reported in the literature.