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Rigid-Rod Polymer Synthesis: Development of Mesophase Polymerization in Strong Acid Solutions

Published online by Cambridge University Press:  26 February 2011

James F. Wolfe*
Affiliation:
SRI International, Menlo Park CA 94025
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Abstract

The development of a method for polycondensation of rigid-rod poly(benzazoles) in poly(phosphoric acid) (PPA) in the lyotropic mesophase has led to an understanding of the synthesis variables that determine the important liquid crystalline product characteristics. These product variables, in turn, control processibility and final fiber or film properties. This paper provides a review of the effects of polymer concentration, solvent composition, polymerization temperature, and monomer purity on two liquid crystalline product characteristics: molecular weight achieved during polymerization, and concentrated solution properties, such as rheological and phase behavior. Central to the understanding of these effects are the factors affecting the polymerization rate. The methods for controlling these synthesis variables are also reviewed. Investigation of alternatives to PPA as the polymerization solvent resulted in a method to obtain high molecular weight poly(2,5-benzoxazole) by adding 40-45 wt % of P2O5 to methanesulfonic acid.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

1. Arnold, F. E. and Deusen, R. L. van, J. Appl. Polym. Sci., 15, 2035 (1971).Google Scholar
2. Kwolek, S. L., U.S. Patent No. 3671 542 (20 June 1972).Google Scholar
3. Kurihara, M. and Yoda, N., J. Macromol. Sci. A–1, 6, 1069 (1967).Google Scholar
4. Wolfe, J. F. and Arnold, F. E., Macromolecules 4, 909 (1981).Google Scholar
5. Choe, E. W. and Kim, S. N., Macromolecules 4, 920 (1981).Google Scholar
6. Wolfe, J. F., Loo, B. H., and Arnold, F. E., Macromolecules 4, 915 (1981).Google Scholar
7. Allen, S. R., Filippov, A. G., Farris, R. J., Thomas, E. L., Wong, C.-P, Berry, G. C., and Chenevey, E. C., Macromolecules 4,1135 (1981).Google Scholar
8. Wolfe, J. F., Sybert, P. D., Sybert, J. R., and Wilson, B., U.S. Patent No. 4 533 724 (6 August 1985).Google Scholar
9. Wolfe, J. F., Sybert, P. D., and Sybert, J. R., U.S. Patent No. 4 533 693 (6 August 1985).Google Scholar
10. Eaton, P. E., Carison, G. R., and Lee, J. T., J. Org. Chem. 38, 4071 (1973).Google Scholar
11. Ueda, M., Sugita, H., and Sato, M., J. Polym. Sci., Part A: Polym. Chem. Ed. 24, 1019 (1986).Google Scholar
12. Ueda, M., Sato, M., and Mochizuki, A., Macromolecules 18, 2723 (1985).Google Scholar
13. Ueda, M. and Sugita, H., J. Polym. Sci.: Part A: Polym. Chem. 26, 159 (1988).Google Scholar