Liquid crystal polymers: Studies of labelled parts by Neutron scattering

The studies of the conformation of comb-like liquid crystal polymers have been made by Small Angle Neutron Scattering (SANS) with samples containing mixtures of totally protonated polymers and homologous polymers with deuterated backbones. For a polymethacrylate the conformation of a chain is determined in the isotropic nematic and smectic phases. Theoretical predictions of Renz and Warner (similar to the hairpin model of de Gennes) are verified from the temperature dependence of the radius, parallel to the director, of one chain in the smectic phase. When the terminal groups of the pendant part of the monomer are deuterated a segregation seems to occur. The problem of the generalization of results is raised.