Effect of the composition on the structure and ferroelectric properties of side chain liquid crystalline copolyacrylates

The structure and physical properties of two side chain liquid crystalline polyacrylates are discussed, one bearing biphenyl core and chiral carbon atom in the flexible spacer, and the other a phenyl benzoate core. The biphenyl version displays two smectic phases of S* F and S* F types and no ferroelectric switching. The phenyl benzoate variant displays a single S C phase. The copolymerisation of the two monomers led to polymeric materials exhibiting a S* c polymorphism and composition dependent structural features. Only the copolymer of equimolar composition displayed a strong piezoelectric response in the S* F phase and ferroelectric behaviour in the lower temperature S* c modification.