The Effect of Polyamic Acid Binder Concentration on the Processability and Properties of LaRC TPI Composites Made by Suspension Prepregging

Abstract

Unidirectional carbon fiber/LaRC TPI composites were prepared by aqueous suspension prepregging. The matrix material was fully imidized LaRC TPI powder, and the binder was LaRC TPI polyamic acid. The effect of the concentration of the polyamic acid binder on composite processability and properties was studied. An optimum concentration range of 2.9-9.4% weight/weight binder/matrix was found that resulted in good prepreg handling characteristics and good consolidation. A binder concentration 2 13.1% led to poorer consolidation of the composites due to an increase in the melt viscosity of the matrix. This increase was probably due to a combination of crosslinking and chain extension of the polyamic acid during the imidization step. Formation of the crosslinked structure was supported by transverse flexure, meso-indentation, and solubility tests.

Keywords

LaRC TPI polyimide polyamic acid suspension prepregging aqueous slurry transverse flexure meso-indentation thermoplastic composites

References

1. Seferis, J. C. and K. J. Ahn . 1989. 34th International SAMPE Symposium, 34:63-63.

2. Penn, L. S. and J. D. Muzzy . 1989. "Thermoplastic Composites," Chapter 3 in Reference Book for Composites Technology. Lancaster, PA: Technomic Publishing Co., Inc., 1:49-60.

3. Clemans, S. and T. Hartness . 1989. SAMPE Quarterly, 20(4):38-38.

4. Goodman, K. E. 1990. "Thermoplastic Prepreg Manufactured by Solution Impregnation," M. S. Thesis, Engineering Science and Mechanics Department, Virginia Tech.

5. Leeser, D. and B. Banister . 1989. 21st International SAMPE Technical Conference, 21:507-507.

6. Muzzy, J. D. , J. B. Varughese and P. H. Yang . 1991. 36th International SAMPE Symposium, 36:1523-1523.

7. Edie, D. D. , B. W. Gantt , G. C. Lichfield , M. J. Drews and M. S. Ellison . 1989. Advances in Thermoplastic Matrix Composite Materials, ASTM STP 1044. Philadelphia, PA.

8. Edie, D. D. , G. C. Lichfield , M. J. Drews , M. S. Ellison , L. E. Allen , J. R. McCollum and H. L. Thomas . 1988. "NASA Project NAG 1-680" in NASA Annual Report 1987-88, Clemson, SC: Clemson University.

9. Ogden, A. L. , M. W. Hyer , J. T. Muellerleile , G. L. Wilkes and A. C. Loos . 1990. American Society for Composites, 5th Technical Conference, E. Lansing, MI, pp. 249-258.

10.

10. Baucom, R. M. and J. M. Marchello . 1990. 35th International SAMPE Symposium, 35:175-175.

11.

11. Marchello, J. M. 1991. 36th International SAMPE Symposium, 36:68-68.

12.

12. Towell, T. W. , D. E. Hirt and N. J. Johnston . 1990. 22nd International SAMPE Technical Conference, 22:1156-1156.

13.

13. Texier, A. and R. M. Davis . 1991. Proceedings of the Society of Plastics Engineers ANTEC'91 Conference, 37:2018-2018.

14.

14. Lyon, K. R. , A. Texier , A. Gungor , R. M. Davis and J. E. McGrath . 1992. 37th International SAMPE Symposium, 37:1301-1301.

15.

15. Texier, A. , R. M. Davis , K. R. Lyon , A. Gungor , J. E. McGrath , H. Marand and J. S. Riffle . 1993. Polymer, 34(4):896-896.

16.

16. Texier, A. 1990. "The Fabrication of Carbon-Fiber Composites by Aqueous Suspension Prepregging with LaRC TPI and PEEK," M. S. Thesis, Chemical Engineering Department, Virginia Tech.

17.

17. Yu, T. H. and R. M. Davis . 1993. Journal of Thermoplastic Composite Materials, 6(1):62-62.

18.

18. Gonzalez-Ibarra, A. 1993. "The Effects of Polymeric Binders on the Processability and Properties of Composites Made by Suspension Prepregging," M. S. Thesis, Chemical Engineering Department, Virginia Tech.

19.

19. Hou, T. H. and J. M Bay . 1990. 35th International SAMPE Symposium, p. 1594-1594.

20.

20. Johnston, N. J. and T. L. St. Clair . 1986. 18th International SAMPE Technical Conference, p. 53-53.

21.

21. Weaton, J. W. , D. M. Peters and K. L. Thomas , eds. 1987. ASTM Engineering s Guide to Composite Materials, Metals Park, Ohio.

22.

22. Lesko, J. J. 1991. "Indentation Testing of Composite Materials: A Novel Approach to Measuring Interfacial Characteristics and Engineering Properties," M. S. Thesis, Engineering Science and Mechanics Department, Virginia Tech.

23.

23. Lesko, J. J. and R. W. Armstrong. 1992. U.S. Patent 5, 133, 210.

24.

24. Carman, G. P. , J. J. Lesko , K. L. Reifsnider and D. A. Dillard . 1993. Journal of Composite Materials, 27(3):303-303.

25.

25. Lesko, J. J. , G. P. Carman , D. Dillard and K. L. Reifsnider . 1993. Composite Materials: Fracture and Fatigue (4th Symposium ASTM), ASTM SP 1156, 4:401-401.

26.

26. Ho, H. , J. J. Lesko , H. T. Budiman , M. W. Tsai , J. Morton , K. L. Reifsnider , S. Wilkinson , and T. C. Ward . 1993. Journal of Adhesion, 42:39-39.

27.

27. Buscall, R. and R. H. Ottewill . 1985. "The Stability of Polymer Latices," in Polymer Colloids, R. Buscall , T. Comer and J. F. Stageman , eds., New York: Elsevier Science Publishing Co.

28.

28. Ferry, J. D. 1961. Viscoelastic Properties of Polymers, New York: John Wiley & Sons, Inc., pp. 1-5.

29.

29. Farinato, R. S. , S. S. Kaminski and J. L. Courter . 1990. Journal of Adhesion Science Technology, 4(8):633-633.

30.

30. Adams, D. F. , T. R. King and D. M. Blacketter . 1990. Composite Science and Technology, 39:341-341.

31.

31. Madhukar, M. S. and L. T. Drzal . 1991. Journal of Composite Materials, 25:958-958.