Strain induced nanocavitation and crystallization in natural rubber probed by real time small and wide angle X‐ray scattering |
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| Authors: | Huan Zhang Arthur K Scholz Yannick Merckel Mathias Brieu Daniel Berghezan Edward J Kramer Costantino Creton |
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| Institution: | 1. Laboratoire de Sciences et Ingénierie de la Matière Molle, , Paris, 75005 France;2. Materials Research Laboratory, University of California Santa Barbara, , California, 93106;3. Department of Materials, University of California Santa Barbara, , California, 93106;4. LML, , France;5. Michelin, , F‐63040 Clermont Ferrand, France;6. Department of Chemical Engineering, University of California Santa Barbara, , California, 83106 |
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| Abstract: | The concomitant appearance of crystallites and nanocavities under uniaxial strain is investigated by X‐ray scattering in a model natural rubber system. The nanocavities appear after crystallization and only when the true stress is above a critical cavitation stress σCav. The presence of crystallites alone does not influence the calculation of the void volume fraction ?void. The nanocavities formed are 20–50 nm in size with a constant aspect ratio. The presence of filler shifts the critical crystallization extension ratio λCry, λCav, and σCav to lower values. The clear correlation between σCav and the crystallinity at the onset of cavitation χC(λCav) implies that the crystallites take most of the mechanical loading thus delaying the cavitation in the amorphous phase. Under cyclic loading, nanocavitation is significant only in the first loading and in the successive loadings if the extension ratio is above its maximum historical value. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1125–1138 |
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| Keywords: | cavitation crystallization elastomers natural rubber nanocomposite SAXS WAXS |
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