Synthesis and properties of two new liquid crystals: an analytical and thermodynamic study

Synthesis, analytical performances, thermodynamic and surface properties of two new liquid crystals substituted with poly(ethylene oxide) chains are d escribed. The first of them is N,N'-diphenyl-[4-{2,3,4-tri[2-(2-metoxyethox y)ethoxyl]-benzylidene}imine]piperidine (LC1) and the second is 2-hydroxy-3 -methyl-4-{4-[2-(2-butoxyethoxy)ethoxy]} 4'-{4-[2-(2-butoxyethoxy)ethoxy]st yryl}azobenzene (LC2). The nematic ranges of the two liquid crystals, deter mined by differential scanning calorimetry do not interfere. The analytical and thermodynamic studies of LC(1)and LC2 in the solid, nematic and liquid state were done using a series of appropriate solutes. Comparison of the a nalytical performances shows a better efficiency in the nematic state. (C) 1999 Elsevier Science B.V. All rights reserved.