Neutron scattering study and discussion of the backbone conformation in the nematic phase of a side chain polymer

A small angle neutron scattering study of a mesomorphic side chain polyacrylate in the nematic phase shows that the backbone adopts a prolate conformation. This observation is discussed in relation to the previous determinations of backbone anisotropy in the nematic phase of other side chain polymers. On the basis of the comparison with these previous determinations and also with the results obtained on other related systems, the assumption is made that, provided that the spacers are long enough, the natural tendency of the backbones is to adopt a prolate shape in any nematic phase devoid of smectic fluctuations.