Optical effects in ordered surface layers of polymer films

The spontaneous ordering of fragments of macromolecules and the effect of birefringence in casted polymer films is described in terms of approximation of strong planar-orientation order in the multi-chain model, which takes into account both intraand interchain orientational interactions of chain kinetic units, as well as for transversal fluctuation of their orientation in the layers. Packing of chains in the plane-ordered state is impossible unless the interchain interaction parameter has a critical value. This value decreases with chain bending rigidity. The calculated dependences of the limiting values of the quadrupole orientation order parameter on the length of the Kuhn statistical segment describe reasonably well the experimental data obtained earlier for various polymer-homologues. The monolayer thickness in the films of some polymers has been calculated from the fitting of the theoretical results to the experimental data obtained from the study of the surface birefringence in the polymer films.