Abstract.
Inhomogeneous deformations are observed in stretched natural rubber of different crosslink density; the conditions of observation, nucleation and propagation are given in the first part of the paper. In samples of low crosslink density these inhomogeneities recall necking observed in others materials and in glassy polymers when the materials are drawn above a critical draw ratio. The difference is that in natural rubbers, NR, they nucleate and propagate at constant stress during unloading. This phenomenon, called inverse yielding appears during recovery only if the samples have been drawn previously in the hardening domain. During necking propagation the stress is constant. The mechanical and crystallinity properties of samples with and without inverse yielding are studied as a function of draw ratio, crosslink density and temperature. In the second part of the paper this transition zone (neck) of thickness 2 mm is studied by WAXS at the synchrotron source. From the orientation of NR crystallites and from the orientation of the stearic acid (2%, present in this type of rubber) we conclude that the deformation in the neck follows the flow lines. From the local crystallinity of the NR crystallites one deduces the local draw ratio across this transition zone. We suggest that in all these rubbers, which present a plateau of the recovery stress strain curve, micronecking exists. This effect is discussed in the framework of the Flory theory.-1
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
P.J. Flory, Principle of Polymer Chemistry (Cornell University Press, 1953).
L.R.G. Treloar, The Physics of Rubber Elasticity (Oxford University Press, Oxford, 1975).
J.E. Mark, B. Erman, F.R. Eirich, Science and Technology of Rubber, second edition (Academic Press, San Diego, 1994).
A.N. Gent, S. Kawahara, J. Zhao, Rubber Chem. Technol. 71, 668 (1998).
S. Toki, I. Sics, S. Ran, L. Liu, B.S. Hsiao, S. Murakami, K. Senoo, S. Kohjiya, Macromolecules 35, 6573 (2002).
S. Trabelsi, P.A. Albouy, J. Rault, Macromolecules 36, 7624 (2003),
Y. Miyamoto, H. Yamao, K. Sekimoto, Macromolecules 36, 6462 (2003).
S. Trabelsi, P.A. Albouy, J. Rault, Macromolecules 35, 10054 (2002).
S. Trabelsi, Thesis, Orsay (2002).
H.P. Klug, L.E. Alexander, in X-ray Diffraction Procedures (Wiley, New York, 1954).
H. Lavebratt, B. Stenberg, P.E. Werner, Polymer 34, 1109 (1993).
G.R. Mitchell, Polymer 25, 1562 (1984).
S. Trabelsi, P.A. Albouy, J. Rault, Rubber Chem. Technol. 77, 303 (2004).
A.N. Gent, Trans. Faraday Soc. 50, 521 (1954)
H.G. Kim, L. Mandelkern, J. Polym. Sci. A2 6, 181 (1968).
A.N. Gent, L.Q. Zhang, J. Polym. Sci., Polym. Phys. Ed. 39, 811 (2001).
W.R. Krigbaum, R.J. Roe, J. Polym. Sci. A2 439, 1 (1964),
R. Kitamaru, H. Dong, W. Tsuji, Macromol. Chem. 8, 98 (1966).
R.J. Gaylord, J. Polym. Sci., Polym. Lett. Ed. 13, 337 (1975)
R.J. Gaylord, D. Lohse, J. Polym. Eng. Sci. 16, 163 (1976).
P.J. Flory, J. Chem. Phys. 15, 397 (1947).
K. Smith, J. Polym. Eng. Sci. 16, 168 (1976).
A. Postuma de Boer, A.J. Pennings, Faraday Discuss. Chem. Soc. 68, 345 (1979).
J. Brandrup, E.T. Immergut (Editors), Polymer Handbook (Inter Science Publ., New York, 1965).
J. Rault, E. Souffache, J. Polym. Sci. Polym. Phys. Ed. 27, 1349 (1989).
E. Souffache, J. Rault, Macromolecules 22, 3581 (1989).
D. Goritz, Angew. Makromol. Chem. 202/203, 309 (1992).
D. Luch, G.S.Y. Yeh, J. Macromol. Sci., Part B Phys. 7, 121 (1973).
I.R. Hardin, G.S.Y. Yeh, J. Macromol. Sci., Part B Phys. 7, 393 (1973).
Faraday Discuss. Chem. Soc., Vol. 68 (1979).
J.D. Ferry, Viscoelastic Properties of Polymers (Wiley, New York, 1961).
P. Thirion, R. Chassenet, Rev. Gen. Caoutch. 41, 271 (1964).
D.J. Plazek, J. Polym. Sci., Polym. Phys. Ed. 74, 5 (1966).
L.C. Struik, Physical Aging in Amorphous Polymers and Others Materials (Elsevier, Amsterdam, 1978).
J.M. Drake, J. Klafter, R. Kopelman (Editors), Dynamics in Small Confining Systems (Materials Research Society, Pittsburg, 1990).
J.L. Keddie, R.A.L. Jones, R.A. Cory, Europhys. Lett. 27, 59 (1994).
J.A. Forrest, K. Dalnoki-Veress, J.R. Dutcher, Phys. Rev. E 56, 5705 (1997).
J. Rault, J. Macromol. Sci., Part B Phys. 42, 1235 (2003).
M. Botev, P. Judeinstein, J. Rault, Polymer 40, 5227 (1999).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Albouy, P.A., Marchal, J. & Rault, J. Chain orientation in natural rubber, Part I: The inverse yielding effect. Eur. Phys. J. E 17, 247–259 (2005). https://doi.org/10.1140/epje/i2004-10145-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1140/epje/i2004-10145-6