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Shear Induced Morphology Of Semicrystalline BlockCopolymers

Published online by Cambridge University Press:  15 February 2011

Peter Kofinast  and
Robert E. Cohen
Peter Kofinast
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
Robert E. Cohen
Affiliation:
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
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Abstract

A series of semicrystalline diblock copolymers of poly (ethylene) / poly(ethylene-propylene) (E/EP) were subjected to high levels of plane straincompression using a channel die. Deformations were imposed both below andabove the melting point of the E block. The crystallographic andmorphological textures were examined using wide-angle x-ray diffraction polefigure analysis and two dimensional small-angle x-ray scattering. Thelattice unit cell orientation of the crystallized E chains with respect tothe lamellar superstructure was determined, as well as the lamellarorientation relative to the specimen boundaries. When the diblocks aretextured above the E block melting point at various compression ratios, thelamellae orient perpendicular to the plane of shear, while texturing below Tm causes the lamellae to orient parallel to the plane ofshear. The orientation of the crystallized E chains was perpendicular to thelamellar normal, irrespective of the texturing temperature. The variousshear-induced lamellar morphologies have potential applications in gastransport control to develop membranes for use in gas separations or asbarrier Materials.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 321: Symposium E – Crystallization and Related Phenomena in Amorphous Materials—Ceramics, Metals, Polymers, and Semiconductors , 1993 , 523
Copyright
Copyright © Materials Research Society 1994

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References

[1] Douzinas, K. C., Cohen, R. E., Macromolecules, 25, 5030 (1992).Google Scholar
[2] Cohen, R. E., Bellare, A., Drzewinski, M. A., Macromolecules, submitted.Google Scholar
[3] Almdal, K., Koppi, K. A., Bates, F. S., Macromolecules, 25, 1743 (1992).Google Scholar
[4] Koppi, K. A., Tirrell, M., Bates, F. S., Phys. Rev. Lett, 70 (10), 1449 (1993).Google Scholar
[5] Koppi, K. A., Tirrell, M., Bates, F. S., Almdal, K., Colby, R. H., Journal De Physique II, 2 (11), 1941 (1943).Google Scholar
[6] Mohajer, Y.. Wilkes, G. L., McGrath, J. E., Polymer, 23, 1523 (1982).Google Scholar
[7] Seguela, R., Prud'homme, J., Polymer, 30 1446 (1989).Google Scholar
[8] Rangarajan, P., Register, R. A., Fetters, L. J., Blends of Amorphous and Crystalline Polymers Symposium, ACS National Meeting, August 1992, Washington, DC,Google Scholar
Division of Polymer Chemistry, Polymer Preprints, 33 (2) (1992), Macromolecuîes, in press.Google Scholar
[9] Kofinas, P., Cohen, R. E., Halasa, A. F., Polymer, in press.Google Scholar
[10] Halasa, A. F., U.S. Patent 3 872 072.Google Scholar
[11] Cohen, R. E., Cheng, P. -L., Douzinas, K., Kofinas, P., Berney, C. V., Macromolecules, 23, 324 (1990).Google Scholar
[12] Lin, L., Argon, A. S., Macromolecules, 25, 4011 (1992).Google Scholar
[13] Song, H. H., Argon, A. S., Cohen, R. E., Macromolecules, 23, 870 (1990).Google Scholar
[14] Galeski, A., Argon, A. S., Cohen, R. E., Macromolecules, 25, 5705 (1992).Google Scholar
[15] Gray, R. W., Young, R. J., J. Mater. Sci, 9, 521 (1974).Google Scholar