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Chain-End Defects in Extended-Chain Polymer Solids

Published online by Cambridge University Press:  29 November 2013

David C. Martin ,
Patricia M. Wilson ,
Jun Liao  and
Marie-Christine G. Jones
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Extract

Understanding the influence of local variations in symmetry (“defects”) on the macroscopic properties of polymers in the condensed state is an ongoing experimental and theoretical challenge. Studies of defects in solids require the most information-intensive description of microstructure since it is not possible to describe a “defect” without understanding the morphology of the majority phase as well.

The nature of defects in polymers has been discussed elsewhere, including other articles in this issue of the MRS Bulletin. The structure, properties, and mobility of defects in polymers are all profoundly influenced by the covalently bonded chain backbone. In polymers, there are unique defects such as chain folds and twists that have no obvious analogue in materials of small molar mass. Here, we examine a particular type of defect that is present in all polymer systems with finite molecular weight: chain ends. Our interest will focus on chain ends in polymers that are essentially fully extended parallel to a certain preferred orientation axis.

The extended-chain microstructure was originally envisioned by Staudinger as a “continuous crystal” in which high-molecular-weight polymers would be perfectly oriented and close-packed together laterally. Extended-chain polymer fibers such as poly(paraphenylene terephthalamide) (PPTA or Kevlar®), gelspun polyethylene (Spectra®), and the rigid-rod polymers poly(paraphenylene benzobisthiazole) (PBZT) and poly(paraphenylene benzobisoxazole (PBZO or PBO) (Structure 1) closely approach this conceptual limit. The outstanding tensile moduli (100–400 GPa) and tensile strengths (2–4 GPa or higher) of these fibers have generated considerable interest for lightweight structural applications. Extendedchain polymers can also be prepared by solid-state polymerizations of appropriate monomer precursors. Perhaps the most familiar of this latter class of materials are the polydi-acetylenes, first developed by Wegner.

Type
Defects in Polymers
Information
MRS Bulletin , Volume 20 , Issue 9 , September 1995 , pp. 47 - 51
Copyright
Copyright © Materials Research Society 1995

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References

1.Predecki, P. and Statton, W.O., J. Appl. Phys. 37 (1966) p. 4,053.CrossRefGoogle Scholar
2.Wunderlich, B., Macromolecular Physics: Volume 1: Crystal Structure, Morphology, Defects (Academic Press, New York, 1973).Google Scholar
3.Reneker, D.H. and Mazur, J., Polym. 24 (1983) p. 1,387.CrossRefGoogle Scholar
4.Zerbi, G., in Encyclopedia of Polymer Science and Engineering, edited by Mark, H.F., Bikales, N., Overber, C., and Menges, G. (John Wiley & Sons, New York, 1985).Google Scholar
5.Martin, D.C. and Thomas, E.L., MRS Bulletin XII (8) (1987) p. 27.CrossRefGoogle Scholar
6.Martin, D.C., Trends in Polym. Sci. 1 (6) (1993) p. 178.Google Scholar
7.Staudinger, H., Die Hochmolekularen Organischen Verbindungen (Springer-Verlag, Berlin, 1932).CrossRefGoogle Scholar
8.Adams, W. and Eby, R., MRS Bulletin XII (8) (1987) p. 22.CrossRefGoogle Scholar
9.Wegner, G., Z. Naturforsch. 24b (1969) p. 824.CrossRefGoogle Scholar
10.Martin, D.C. and Thomas, E.L., Polym. 36 (9) (1995) p. 1,743.CrossRefGoogle Scholar
11.Bates, F.S., Science 251 (1991) p. 898.CrossRefGoogle Scholar
12.Young, R.J. and Lovell, P.A., Introduction to Polymers, 2nd ed. (Chapman & Hall, London, 1991).CrossRefGoogle Scholar
13.Martin, D.C. and Thomas, E.L., Macromolecules 24 (1991) p. 2,450.CrossRefGoogle Scholar
14.Jiang, T., Rigney, J., Jones, M-C.G., Markoski, L.J., Spilman, G.E., Mielewski, D.F., and Martin, D.C., Macromolecules 28 (1995) p. 3,301.CrossRefGoogle Scholar
15.de Gennes, P.G. and Prost, J., The Physics of Liquid Crystals (Clarendon Press, Oxford, 1993).CrossRefGoogle Scholar
16.Prost, J., Liq. Cryst. 8 (1) (1990) p. 123.CrossRefGoogle Scholar
17.Galiotis, C., Read, R.T., Yeung, P.H.J., Young, R.J., Chalmers, I.F., and Bloor, D., J. Polym. Sci., Poly. Phys. Ed. 22 (1984) p. 1,589.CrossRefGoogle Scholar
18.Day, D. and Lando, J.B., Macromolecules 13 (1980) p, 1,483.CrossRefGoogle Scholar
19.Read, R.T. and Young, R.J., J. Mater. Sci. 19 (1984) p. 327.CrossRefGoogle Scholar
20.Wilson, P.M. and Martin, D.C., J. Mater. Res. 7 (11) (1992) p. 3,150.CrossRefGoogle Scholar
21.Wilson, P.M., PhD dissertation, The University of Michigan, 1994.Google Scholar
22.Bartenev, G.M. and Valishin, A.A., Mekhanika Polimerov 3 (1970) p. 458.Google Scholar
23.Yoon, H.N., Colloid Polym. Sci. 268 (1990) p. 230.CrossRefGoogle Scholar
24.Termonia, Y., Meakin, P., and Smith, P., Macromolecules 18 (1985) p. 2,246.CrossRefGoogle Scholar
25.Termonia, Y. and Smith, P., Polym. 27 (1986) p. 1,845.CrossRefGoogle Scholar
26.Termonia, Y. and Smith, P., Polym. Commun. 30 (1989) p. 66.Google Scholar
27.Termonia, Y., J. Poly. Sci. B, Polym. Phys. Ed. 33 (1995) p. 147.CrossRefGoogle Scholar
28.Jones, M-C.G. and Martin, D.C., Macromolecules in press.Google Scholar
29.Amornsakchai, T., Cansfield, D.L.M., Jawad, S.A., Pollard, G., and Ward, I.M., J. Mater. Sci. 28 (1993) p. 1,689.CrossRefGoogle Scholar
30.Martin, D.C., Macromolecules 25 (1992) p. 5,171.CrossRefGoogle Scholar
31.Mayo, S.L., Olafson, B.D., and Goddard, W.A., J. Phys. Chem. 94 (1990) p. 8,897.CrossRefGoogle Scholar
32.Cox, H.L., J. Appl. Phys. 3 (1952) p. 72.Google Scholar
33.Liao, J., PhD dissertation, The University of Michigan, 1995.Google Scholar
34.Sixl, H., in Proc. NATO Advanced Research Workshop (Dordrecht, Nijdorf, 1984).Google Scholar
35.Mataré, H.F., Defect Electronics in Semiconductors (Wiley Interscience, New York, 1971).Google Scholar
36.Chandhari, P., Chi, C.J., Dimos, D.B., Mannhart, J.D., and Tsuel, C.C., U.S. Patent No. 5,162,298 (1992).Google Scholar
37.Cho, F.Y., Penunuri, D., and Falkner, R.F., U.S. Patent No. 5,125,136 (1992).Google Scholar
38.Horowitz, G., Fichou, D., Feng, X.Z., Xu, Z.G., and Gamier, F., Solid State Commun. 72 (1989) p. 381.CrossRefGoogle Scholar
39.Gamier, F., Hajlaoui, R., Yassar, A., and Srivastava, P., Science 265 (1994) p. 1,664.Google Scholar
40.Assadi, A., Spetz, A., Willander, M., Svensson, C., Lundstrom, I., and Inganas, O., Sensors and Actuators B 20 (1994) p. 71.CrossRefGoogle Scholar
41.Salaneck, W.R. and Bredas, J.L., Solid State Commun. 92 (1–2) (1994) p. 31.CrossRefGoogle Scholar
42.Braun, D., Gustafsson, G., McBranch, D., and Heeger, A.J., J. Appl. Phys. 72 (2) (1992) p. 564.CrossRefGoogle Scholar