Synthesis and properties of mesogen‐jacketed liquid crystalline polymers containing bistolane mesogen

On the basis of the concept of mesogen-jacketed liquid crystalline polymers, a series of new methacrylate monomers, (2,5-bis[2-(4′-alkoxyphenyl) ethynyl] benzyl methacrylate (MACn, n = 4, 6, 8, 10, and 12) and 2,5-bis[2-(6′-decanoxynaphthyl) ethynyl] benzyl methacrylate (MANC10), and their polymers, PMACn (n = 4, 6, 8, 10, and 12) and PMANC10 were synthesized. The bistolane mesogen with large π-electron conjugation were side-attached to the polymer backbone via short linkages. Various characterization techniques such as differential scanning calorimetry, wide-angle X-ray diffraction, and polarized light microscopy were used to study their mesomorphic phase behavior. The polymer PMACn with shorter flexible substituents (n = 4) forms the columnar nematic (ϕN) phase, but other polymers with longer flexible tails (n = 6, 8, 10, and 12) can develop into a smetic A (SA) phase instead of a ϕN phase. The PMANC10 containing naphthyl can also form a well-defined SA phase. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010