Lyotropic liquid crystalline polyesters: synthesis of polyesters and copolyesters based on poly(sulfo-p-phenylene nitroterephthalate)

Abstract

The syntheses of the polyesters poly(sulfo-p-phenylene methoxyterephthalate) (4), poly(sulfo-p-phenylene 2-methoxy-5-nitroterephthalate) (5) and poly(sulfo-p-phenylene 2-bromo-5-nitroterephthalate) (6), and the random copolyesters poly([sulfo-p-phenylene nitroterephthalate]_x-co-[sulfo-p-phenylene terephthalate]) (7a–c), poly([sulfo-p-phenylene nitroterephthalate]_y-co-[sulfo-p-phenylene bromoterephthalate]) (8a–c) and poly([sulfo-p-phenylene nitroterephthalate]_z-co-[sulfo-p-phenylene nitro-isophthalate]) (9a–f) are reported. It was found that, of the three new homopolyesters prepared, 5 showed lyotropic behaviour in 1:1 DMSO–H₂O, DMSO and DMF (DMSO=dimethyl sulfoxide; DMF=dimethylformamide). The copolymers were prepared in various monomer compositions in an effort to establish the effect of either (a) diluting the mesogenic character of a known liquid crystalline polyester by reducing the nitro ratio of the substituents, or (b) disrupting the main-chain linearity of the ester back-bone by the introduction of meta-arranged isophthalate units. It was found that the original polyester could incorporate up to 50% bromo- or un-substituted terephthalate units and retain the ability to form lyotropic solutions. In the case of the accommodation of nitroisophthalate units, only 9% could be tolerated. Poly(sulfo-p-phenylene nitroterephthalamide) (10) has also been synthesised and shown to form a lyotropic liquid crystalline phase in DMSO and aqueous DMSO.

References

1. (a) Liquid Crystallinity in Polymers, ed. A. Ciuferri, VCH, Weinheim, Germany, 1997; (b) A. M. Donald and A. H. Windle, Liquid Crystalline Polymers, Cambridge University Press, Cambridge, 1992; (c) C. B. McArdle, Side-Chain Liquid Crystal chloro-Polymers, Blackie, Glasgow, 1987.
2. (a) J. Lin and D. C. Sherrington, Adv. Polym. Sci., 1994, 111, 177; (b) M. Takayamgi and T. Katayose, J. Appl. Polym. Sci., 1984, 29, 141; (c) M. B. Gielselman and J. R. Reynolds, Macromolecules, 1990, 23, 3118; (d) J. Y. Yadhav, W. R. Krigbaum and J. Preston, Macromolecules, 1988, 21, 538; (e) E. J. Vandenberg, W. R. Dively, L. J. Filar, S. R. Patel and H. G. Barth, Polym. Mater. Sci. Eng., 1987, 57, 139; (f) E. J. Vandenberg, W. R. Dively, L. J. Filar, S. R. Patel and H. G. Barth, J. Polym. Sci. Polym. Chem., 1989, 27, 1387.
3. J. Lin, D. C. Sherrington, R. W. Richards, E. Nield and W. A. MacDonald, Macromolecules, 1992, 26, 7107.
4. This work is derived from the PhD Thesis of D. T. B. Hannah, University of Strathclyde, 1996.
5. K. A. Burdett, Synthesis, 1991, 441.
6. Q.-F. Zhou, R. W. Lenz and J.-I. Jin, in Polymeric Liquid Crystals, ed. A. Blumstein, Polym. Sci. Tech., Plenum Press, New York, 1985, p. 257.
7. F. R. Cai and E. T. Samulski, Macromolecules, 1994, 27, 35.
8. H. Takahashi, K. Horie, T. Yamashita, S. Machida, D. T. B. Hannah and D. C. Sherrington, Macromol. Chem. Phys., 1996, 197, 2703.
9. E. J. Vandenberg, W. R. Dively, L. J. Filar, S. R. Patel and H. G. Barth, J. Polym. Sci. Polym. Chem., 1989, 27, 3745.
10. J.-I. Jin, Y.-H. Lee and H.-K. Shim, Macromolecules, 1993, 26, 1805.
11. C. A. Panetta, Z. Fang and N. E. Heimer, J. Org. Chem., 1993, 58, 6146.
12. F. Wessely and M. Grossa, Monatsch. Chem., 1966, 97, 570.
13. N. K. Kochetkov, L. I. Kudryashov and A. N. Nesmeyanov, Bull. Acad. Sci. USSR, 1955, 729.
14. I. Goodman, J. E. McIntyre and D. H. Aldred, ICI Patent 993,272 1965; Chem. Abstr., 1965, 63, 8521e.
15. E.-S. M. E. Mensour, S. H. Kandid, M. E. M. Soliman and M. Ibrahim, Polym. Int., 1992, 29, 61.