Discotic Polymer Liquid Crystals

Boeffel C, Kranig W, Speiss HW (1990) Phase structure of discotic liquid crystal polymers. 13th International Liquid Crystal Conference, July 22-27 Poster no POL-36P... 

The majority of studies using PR-TRMC in recent years have involved complex organic materials such as conjugated polymers or discotic liquid crystals. Inorganic semiconductor materials have however also received attention over the years. The first of these was a study of the radiation-induced conductivity in a powder sample of the high-Tc superconductor DyBajCujOj,. The superconductivity transition at 88 K on cooling was found to be accompanied by a dramatic, sudden increase in the radiation-induced conductivity an effect which... 

Fig. la-d. Molecular structures of rod-like (calamitic) and disc-like (discotic) liquid crystals a) Low molecular weight liquid crystals, b) liquid crystal main chain polymers, c) liquid crystal side chain polymers, d) combined main-chain/side-chain polymers... 

It is worth mentioning that some side-chain liquid crystal polymers and liquid-crystalline networks (M = Cu, Zn, Co, Ni, Pb) have also been prepared, usually preserving the properties of the monomeric discotic units. They may find some interesting applications in the field of onedimensional conductors as well as applications using flexo- and piezo-electricity. 

S. Furumi, M. Kidowaki, M. Ogawa, Y. Nishiura, K. Ichimura, Surface-mediated photoalignment of discotic liquid crystals on azobenzene polymer films. J. Phys. Chem. B 109, 9245-9254 (2005)... 

S. Kumar, Chemistry of Discotic Liquid Crystals From Monomers to Polymers The Liquid Crystals Book Series (CRC Press, Boca Raton, 2011)... 

Kumar S. Chemistry of discotic liquid crystals from monomers to polymers. Liquid crystals book series. Boca Raton, FL CRC Press 2011. ISBN 9781439811436. 

Side chain liquid crystal polymers (SCLCPs) consist of mesogenic structural moieties appended from a polymer backbone (Figure 5.2). The mesogenic units that have been used parallel those previously used for low molar mass liquid crystals, and the stmctural nature of the polymer backbone is widely variable. The mesogenic units (usually calamitic but many discotic types exist) are invariably separated from the polymer backbone by fairly long spacer units which are usually several methylene (-CH -) units,... 

The main-chain and side-chain polymers as well as the classical small-molecule liquid crystals consist essentially of one-dimensional molecules (rods). Low molar mass compounds of two-dimensional discshaped molecules were discovered by Chandrasekhar (1977) to possess liquid crystallinity. They were referred to as discotic liquid crystals. Later research has involved the synthesis and characterization of polymers with discotic moieties connected via flexible spacer groups. 

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