New synthetic approach for the synthesis of liquid crystalline block and graft copolymers

New synthetic approach for the synthesis of liquid crystalline block and graft copolymers

Liquid crystalline block and graft copolymers were synthesized according to the macroinitiator and macroinimer concept. For this purpose, side chain block copolymers (polytetrahydrofuran-b-polymethylmethacrylate) having liquid crystalline 4,4'- cyanobiphenyl blocks were prepared and characterized. Unlike the liquid-crystalline homopolymer with mesogenic units in the side chain, all block and graft copolymers showed a smectic A mesophase. The transition temperatures are hardly affected by the composition and molecular weight of the blolck copolymers.

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  • 1. V. P. Shibaev and N. A. Plate, Adv. Polym. Sci. 60/61, 173 (1984).
  • 2. A. Fradet and W. Heitz, Macromol. Chem. 188, 1613 (1987).
  • 3. B. C. Auman and V. Percec, Polymer Z9, 938 (1988).
  • 4. G. Galli, E. Chiellini, M. Laus, A. S. Angeloni, M. C. Bignozzi and 0. Francescangeli, Mol. Cryst. Liq. Cryst. 154, 429 (1994).
  • 5. 0. Nuyken and R. Weidner, Adv. Polym. Sei. 73/74, 145 (1985).
  • 6. E. I. Serhatli, G. Galli, Y. Yagci and E. Chiellini, Polym. Bull. (Berlin) 34, 539 (1995).
  • 7. G. Galli, E. Chiellini, M. Laus, M. C. Bignozzi and 0. Francescangeli, Makromol. Chem. Phys. 195, 2247 (1994).
  • 8. E. Chiellini, G. Galli, A. S. Angeloni and M. Laus, Trends Polym. Sci. 2, 244 (1994).
  • 9. G. Galli, E. Chiellini, Y. Ya2ci, E. I. Serhatli, M. Laus, M. C. Bignozzi and A. S. Angeloni, Makromol. Chem., Rapid Commun. 14, 185 (1993).
  • 10. M. Laus, M. C. Bignozzi, A. S. Angeloni, O. Francescangeli, G. Galli and E. Chiellini, Polym.3. 2T, 993 (1995).
  • 11. A. K. Alimoglu, A. Ledwith, P. A. Gemmell, G. W. Gray, F. R. S. and D. Lacy, Polymer, ZS, 1342 (1984).
  • 12. E. Franta, L. Reibel, J. Lehmann, S. Penczek, J. Polym. Sci., Symp. 56, 139 (1976).
  • 13. A. Frosini, G. Levita, D. Lupinacci and P. L. Magagnini, Mol. Cryst. Liq.Cryst. 66, 21 (1981).
  • 14. A. K. Alimoglu, A. Ledwith, P. A. Gemmell, G. W. Gray and D. Lacy, Polymer 28, 1342 (1984).