Liquid crystalline side-chain polymers

Abstract

Liquid crystalline side-chain polymers are polymers that have linked conventional low molecular mass liquid crystals (I.e.) as side chains to a polymer backbone. Their properties are experimentally compared with the corresponding low molecular mass I.e. (i) Beginning with a monomeric I.e., with increasing degree of polymerization an increase of the phase transformation temperature of I.e. to isotropic is observed. (ii) The nematic order parameter of the monomers is about 10 % higher than the order parameter of the polymers. Owing to the linkage of the rigid mesogenic molecules to the polymer backbone, their rotation around the long molecular axis differs strongly from that of the monomers, (hi) Owing to the high viscosity of the polymers their response times in the electric field are much larger than the response times of the monomers. If a sufficient length of the flexible spacer that connects the mesogenic molecule to the polymer main chain is assumed, the threshold voltages of the monomers and polymers are of comparable magnitude.