Conformation of LC Side Chain Polymers in the Smectic Phase

Four models for the conformation of the backbone of a LC side chain polymer in the smectic phase are proposed. The models differ with respect to the assumed conformational behaviour of the backbone in the planes between the smectic lamellae. Thermally activated crossing of the backbone through the lamellae (equilibrium effect) as well as entanglement induced crossing (non-equilibrium effect) is considered. The ratio of the radii of gyration normal and perpendicular to the director of the side chains is derived and it is shown how this ratio depends on temperature in the equilibrium model.