BACKBONE CONFORMATION OF A MESOGENIC SIDE-CHAIN POLYACRYLATE

A small-angle neutron scattering study was conducted on a mesogenic polyacrylate. Experimental results show that the liquid-crystal side-chain polymers like polymethacrylates and polyacrylates seem to present, in the nematic and smectic A phases, a similar behavior for homologous mesogenic groups. The more the temperature decreases, the more widely the polymer backbone expands perpendicularly to its mesogenic units and approaches an oblate shape. In contrast to the NMR interpretation, we show that the sense of the global anisotropy is not affected by the steric hindrance of the α-methyl group since the polyacrylate and the polymethacrylate, which bear the same side chains, behave alike.