Recrystallization in Deformed and Heat Treated PET Polymer Sheets

Abstract:

This is a study on texture, decrystallization, and recrystallization in rolled and heat treated semi–crystalline polymers. Experiments were conducted using wide angle Debye-Scherrer-type X– ray diffraction. Changes in crystallinity were quantitatively monitored as a function of strain and annealing time. It was observed that crystallinity drastically drops during deformation in PET. We suggest that amorphization (decrystallization) is a deformation mechanism which acts as an alternative to crystallographic slip depending on the orientation of the nanocrystalline lamellae. Heat treatment leads to the recrystallization of amorphous PET material and to an enhancement of the original texture of the deformed crystals observed before the heat treatment. We explain this phenomenon in terms of oriented nucleation where amorphous material crystallizes alongside existing crystalline lamellae.

• Periodical: Materials Science Forum (Volumes 467-470)
• Pages: 551-556
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.467-470.551
• Online since: October 2004
• Authors: Dierk Raabe, N. Chen
• Keywords: Amorphisation, Cellular Automaton (CA), Crystallization, Decrystallization, Deformation, Growth, PET, Polypropylene (PP), Semi-Crystalline, Spherulite, Texture, X-Ray

References

[1] Asano, T., Balta Calleja, F. J., Flores, A., Tanigaki, M., Mina, M. F., Sawatari, C., Itagaki, H., Takahashi, H. & Hatta, I., Polymer 40 (1999) 6475.

DOI: 10.1016/s0032-3861(98)00839-8

[2] Bedia, E., Murakami, S., Kitade, T. & Kohjiya, S. Polymer 42 (2001) 7299.

[3] Bellare, A., Cohen, R. E. & Argon, A. S., Polymer 34 (1993) 1393.

[4] Göschel, U., Deutscher, K. & Abetz V., Polymer 37 (1996) 1.

[5] Encyclopedia of Polymer Science and Engineering. 2nd edition New York: Wiley, (1985).

[6] Helming, K., Schwarzer, R. A., Rauschenbach, B., Geier, S., Leiss, B., Wenk, H. R., Ullemeier, K. & Heinitz, J., Z. Metallkunde 85 (1994) 545.

[7] Haudin JM, in B. Escaig and C. G'Sell (eds. ), Plastic Deformation of Amorphous and SemiCrystalline Materials, Les Editions de Physique, Les Ulis, 1982, page 291.

[8] Lotz B. & Wittmann J. C., Structure of Polymer Single Crystals, in: Structure and Properties of Polymers, 1993, Vol. ed. E.L. Thomas, Vol. 12 of Materials Science and Technology, ed. by R. W. Cahn, P. Haasen, E. J. Kramer, page 79.

[9] Crist, B., Plastic Deformation of Polymers, in: Structure and Properties of Polymers, 1993, Vol. ed. E.L. Thomas, Vol. 12 of Materials Science and Technology, ed. by R. W. Cahn, P. Haasen, E. J. Kramer, Chapter 10, page 427.

[10] Crist, B., Semicrystalline Polymers: Plastic Deformation, in: Encyclopedia of Materials: Science and Technology, Volume 9, K. H. J. Buschow et al., eds., Elsevier, New York, 2001, page 8427.

DOI: 10.1016/b0-08-043152-6/01506-0

[11] Lee, B. J., Argon, A. S., Parks, D. M., Ahzi, S. & Bartczak, Z., Polymer 34 (1993) 3555.

[12] Bellare, A., Cohen, R. E. & Argon, A. S., Polymer 34 (1993) 1393.

[13] Bartczak, Z., Argon, A. S. & Cohen, R. E., Polymer 35 (1994) 3427.