In situ synchrotron X-ray diffraction study of strain induced crystallisation of natural rubber during fatigue tests

Stéphanie Beurrot (1) , Bertrand Huneau (1) , Erwan Verron (1) , Pierre Rublon (1) , Dominique Thiaudière (2) , Cristian Mocuta (2) , A. Zozulya (2)

1 Matériaux, Procédés et Technologie des Composites
2 SSOLEIL - Synchrotron SOLEIL

A homemade stretching machine has been developed to perform fatigue tests on natural rubber in the synchrotron facility Soleil. Strain induced crystallisation is investigated by wide angle X-ray diffraction during in situ fatigue tests of different minimum and maximum strain levels. The index of crystallinity chi decreases with the number of cycles when the minimum strain level reached during the fatigue test is lower than the critical stretch ratio for melting lambda(M). On the contrary, when the stretch ratio is maintained higher than the critical stretch ratios for melting lambda(M) and crystallisation lambda(C), chi increases with the number of cycles. The size of the crystallites has the same evolution during fatigue testing as chi. On the contrary, the misorientation of the crystallites does not depend on the minimum strain level reached and decreases with the number of cycles for all the fatigue tests.

Mots clés: Natural rubber; Strain induced crystallisation; WAXD; Fatigue

Domaines: Mécanique des matériaux [physics.class-ph]

Stéphanie Beurrot, Bertrand Huneau, Erwan Verron, Pierre Rublon, Dominique Thiaudière, et al.. In situ synchrotron X-ray diffraction study of strain induced crystallisation of natural rubber during fatigue tests. Plastics, Rubber and Composites, 2012, 41 (7), pp.290-295. ⟨10.1179/1743289812Y.0000000028⟩. ⟨hal-01006959⟩