A series of novel liquid crystalline polymers showing a nematic discotic and/or a nematic columnar phase

A series of novel liquid crystalline side chain polyacrylates was prepared, bearing a disk-shaped pentakis(4-methylphenylethynyl)benzene mesogen via a n undecanoxy spacer. By using the concept of the polymer analogous reaction , a variety of copolymers with different alkyl acrylate "co-monomers" and i ncreasing mesogen contents were synthesized. The thermal properties of the polymers were investigated by optical polariz ation microscopy and differential scanning calorimetry. The results indicat ed that the liquid crystalline characteristics of the polymers are not dete rmined by nature of the co-monomers, but mainly by the weight fraction of r igid mesogen present in the material. All polymers exhibit a nematic column ar phase at lower temperatures. Polymers with a high mesogen content (> 61 %-wt) exhibit an additional nematic discotic phase at high temperatures, wh ich is unique for polymeric materials.