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

2011 ◽  
pp. 353-358 ◽  
Author(s):  
S Beurrot ◽  
B Huneau ◽  
E Verron ◽  
P Rublon ◽  
D Thiaudière ◽  
...  
2014 ◽  
Vol 87 (1) ◽  
pp. 184-196 ◽  
Author(s):  
S. Beurrot-Borgarino ◽  
B. Huneau ◽  
E. Verron ◽  
D. Thiaudière ◽  
C. Mocuta ◽  
...  

ABSTRACT Strain-induced crystallization of carbon black-filled natural rubber is investigated by wide-angle X-ray diffraction (WAXD) during in situ fatigue tests using synchrotron radiation. Thanks to an original experimental method, we measure the evolution with the number of cycles of: (i) the index of crystallinity, both (ii) size and (iii) orientation of the crystallites, and finally (iv) the lattice parameters. It is shown that when the minimum stretch ratio of the fatigue test is lower than the onset of melting of the crystallites, then the index of crystallinity and the size of the crystallites decrease, whereas they increase when the minimum stretch ratio is higher than the onset of melting. For all the fatigue tests, the misorientation of the crystallites slightly decreases and the lattice parameters remain constant with the number of cycles.


Soft Matter ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 734-743 ◽  
Author(s):  
Pinzhang Chen ◽  
Jingyun Zhao ◽  
Yuanfei Lin ◽  
Jiarui Chang ◽  
Lingpu Meng ◽  
...  

The structural evolution of NR during stretching at −40 °C and in the strain–temperature space.


Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 294 ◽  
Author(s):  
Konrad Schneider ◽  
Matthias Schwartzkopf

Vulcanized natural rubber (unfilled and filled with 20 phr carbon black) is strained. We suppress the macroscopic formation of fiber symmetry by choosing strip-shaped samples ("pure-shear geometry") and investigate the orientation of the resulting crystallites by two-dimensional wide-angle X-ray diffraction (WAXD), additionally rotating the sample tape about the straining direction. Indications of a directed reinforcing effect of the strain-induced crystallization (SIC) in the thin strip are found. In the filled material fewer crystallites are oriented and the orientation distribution of the oriented crystallites is less perfect. The results confirm, that it is important for the evaluation of crystallinity under deformation to check, whether fiber symmetry can be assumed. This has consequences in particular on the quantitative interpretation of space-resolved scanning experiments in the vicinity of crack tips. Furthermore it raises the question, whether there is an asymmetric reinforcing effect of the SIC in the vicinity of crack tips inside natural rubber.


2012 ◽  
Vol 41 (7) ◽  
pp. 290-295 ◽  
Author(s):  
S. Beurrot-Borgarino ◽  
B. Huneau ◽  
E. Verron ◽  
P. Rublon ◽  
D. Thiaudière ◽  
...  

2005 ◽  
Vol 38 (16) ◽  
pp. 7064-7073 ◽  
Author(s):  
Shigeyuki Toki ◽  
Igors Sics ◽  
Benjamin S. Hsiao ◽  
Masatoshi Tosaka ◽  
Sirilux Poompradub ◽  
...  

2011 ◽  
Vol 84 (3) ◽  
pp. 425-452 ◽  
Author(s):  
Bertrand Huneau

Abstract Strain-induced crystallization of natural rubber was discovered in 1925 by the means of x-ray diffraction and has been widely investigated by this technique until today. The studies devoted to the structure of the crystalline phase of natural rubber are first reviewed. This structure is strongly anisotropic and can be related to the exceptionally good strength and fatigue properties of this material. The relationships between strain-induced crystallization of natural rubber and its mechanical response, during static or tension-retraction tests, are also reviewed and discussed; in particular, the hysteresis of the stress-strain curve is mainly explained by strain-induced crystallization. The kinetics of crystallization under both static and cyclic deformation is also discussed, as well as the influence of different factors, depending either on material composition (crosslink density, carbon black fillers) or on external parameters (temperature, strain rate…).


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