Abstract
The dynamic mechanical properties of “tapered” block polymers consisting of styrene and isoprene were studied in relation to the unique microdomain structure of these polymers. It was found from morphological observations that considerable mixing of the two monomers occurs in the primary structure, giving rise to a class of block polymers consisting approximately of “styrene-rich” and “isoprene-rich” block chains. Microphase-separated domain structures existed in the tapered block polymers prepared by sequential living anionic polymerization. Each domain, however, contained a substantial amount of dissimilar monomeric units, thus having an order-to-disorder transition temperature Tc (the temperature at which the microdomains are dissolved into a homogeneous mixture) lower than that of the ideal block. This lowering in Tc should have a substantial influence on flow behavior. The tapered block polymers gave essentially a single broad primary dispersion. This dispersion is related to the microbrownian motion of segments with a relaxation time between those of the parent homopolymers. The temperature dependence of the shift factor aT obeyed the WLF equation, in spite of the heterophase structure. The mechanical behavior was interpreted using a model in which two incompatible units undergo extensive mixing in each domain, leading to an increase in the interfacial volume fraction.
Similar content being viewed by others
Article PDF
References
Y. Tsukahara, N. Nakamura, T. Hashimoto, H. Kawai, T. Nagaya, Y. Sugimura, and S. Tsuge, Polym. J., 12, 455 (1980). (Part I of this series.)
T. Hashimoto, M. Shibayama, and H. Kawai, Macromolecules, 13, 1237 (1980).
T. Hashimoto, M. Fujimura, and H. Kawai, Macromolecules, 13, 1660 (1980).
T. Hashimoto, M. Shibayama, and H. Kawai, Macromolecules, 16, 1093 (1983).
T. Hashimoto, M. Shibayama, and H. Kawai, Polym. Prepr., Am. Chem. Soc., Div. Polym. Chem., 23(1), 21 (1982).
T. Hashimoto, Proceedings of IUPAC 28th Symposium on Macromolecules, University of Massachusetts, Amherst, MA., 1982, p 705.
T. Hashimoto, Macromolecules, 15, 1548 (1982).
P. J. Flory, “Principles of Polymer Chemistry,” Cornell University Press, Ithaca, New York, N. Y., 1967.
R. J. Roe and W. C. Zin, Macromolecules, 13, 1221 (1980).
R. J. Roe, M. Fishkis, and C. J. Chang, Macromolecules, 14, 1091 (1981).
M. Shibayama, T. Hashimoto, and H. Kawai, Macromolecules, 16, 16 (1983).
L. Leibler, Macromolecules, 13, 1602 (1980).
M. Shibayama, T. Hashimoto, H. Hasegawa, and H. Kawai, Macromolecules, 16, 1427 (1983).
T. G. Fox, Bull. Am. Phys. Soc., 1(3), 123 (1956).
T. Hashimoto, Y. Tsukahara, K. Tachi, and H. Kawai, Macromolecules, 16, 648 (1983). (Part IV of this series.)
Y. Tsukahara, A. Izumi, T. Hashimoto, and H. Kawai, Polym. J., 14, 887 (1982).
S. L. Aggarwal, R. A. Livigni, L. F. Marker, and T. J. Dudek, “Block and Graft Copolymers,” J. J. Burke and V. Weiss, Ed., Syracuse University Press, New York, N. Y., 1973, pp 157—194.
M. Shen and D. H. Kaelble, J. Polym. Sci., B, 8, 149 (1970).
D. G. Fesko and N. W. Tschoegl, Intern. J. Polym. Mater., 3, 51 (1974).
T. Soen, M. Shimomura, T. Uchida, and H. Kawai, Colloid. Polym. Sci., 252, 933 (1974).
G. Kraus and K. W. Rollmann, J. Polym. Sci., Polym. Phys. Ed., 14, 1133 (1976).
J. Bares, Macromolecules, 8, 244 (1975).
J. D. Ferry, “Viscoelastic Properties of Polymers,” Wiley, New York, N. Y., 1980, Chapter 11.
E. Helfand, Macromolecules, 8, 552 (1975).
H. Hashimoto, M. Fujimura, T. Hashimoto, and H. Kawai, Macromolecules, 14, 844 (1981).
A. Todo, H. Uno, K. Miyoshi, T. Hashimoto, and H. Kawai, Polym. Eng. Sci., 17, 587 (1977).
G. Kraus and K. W. Rollmann, Angew. Makromol. Chem., 16/17, 271 (1971).
M. Takayanagi, H. Harima, and Y. Iwata, J. Soc. Mater. Sci. Jpn., 12, 389 (1963).
C. I. Chung and J. C. Gale, J. Polym. Sci., Polym. Phys. Ed., 14, 1149 (1976).
E. V. Gouinlock and R. S. Porter, Polym. Eng. Sci., 17, 534 (1977).
E. R. Pico and M. C. Williams, Polym. Eng. Sci., 17, 573 (1977).
C. I. Chung and M. I. Lin, J. Polym. Sci., Polym. Phys. Ed., 16, 545 (1978).
C. I. Chung, H. L. Griesbach, and L. Young, J. Polym. Sci., Polym. Phys. Ed., 18, 1237 (1980).
J. M. Widmaire and G. C. Meyer, J. Polym. Sci., Polym. Phys. Ed., 18, 2217 (1980).
G. Kraus and T. Hashimoto, J. Appl. Polym. Sci., 27, 1745 (1982).
H. Watanabe, T. Kotaka, T. Hashimoto, M. Shibayama, and H. Kawai, J. Rheol., 26, 153 (1982).
T. Hashimoto, M. Shibayama, H. Kawai, H. Watanabe, and T. Kotaka, Macromolecules, 16, 361 (1983).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hashimoto, T., Tsukahara, Y. & Kawai, H. Structure and Properties of Tapered Block Polymers of Styrene and Isoprene II. Dynamic Mechanical Responses and Their Structural Interpretations. Polym J 15, 699–711 (1983). https://doi.org/10.1295/polymj.15.699
Issue Date:
DOI: https://doi.org/10.1295/polymj.15.699
Keywords
This article is cited by
-
Interface manipulated two-phase nanostructure in a triblock terpolymer with a short middle segment
Polymer Journal (2016)
-
Self-assembled block copolymers: Bulk to thin film
Macromolecular Research (2008)