A stroboscopic X-ray apparatus for the study of the kinetics of strain-induced crystallization in natural rubber

Polymer ◽  
2012 ◽  
Vol 53 (15) ◽  
pp. 3313-3324 ◽  
Author(s):  
Pierre-Antoine Albouy ◽  
Gilles Guillier ◽  
Denis Petermann ◽  
Arnaud Vieyres ◽  
Olivier Sanseau ◽  
...  
Keyword(s):  
Natural Rubber ◽  
X Ray ◽  
Strain Induced Crystallization ◽  
Kinetics Of ◽  
Induced Crystallization

scholarly journals STRAIN-INDUCED CRYSTALLIZATION OF NATURAL RUBBER: A REVIEW OF X-RAY DIFFRACTION INVESTIGATIONS

2011 ◽  
Vol 84 (3) ◽  
pp. 425-452 ◽  
Author(s):  
Bertrand Huneau
Keyword(s):  
Natural Rubber ◽  
Mechanical Response ◽  
Strain Curve ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strain Induced Crystallization ◽  
Temperature Strain ◽  
Kinetics Of ◽  
Induced Crystallization

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…).

DEPENDENCE OF THE ONSET OF STRAIN-INDUCED CRYSTALLIZATION OF NATURAL RUBBER AND ITS SYNTHETIC ANALOGUE ON CROSSLINK AND ENTANGLEMENT BY USING SYNCHROTRON X-RAY

2017 ◽  
Vol 90 (4) ◽  
pp. 728-742 ◽  
Author(s):  
Watcharin Sainumsai ◽  
Shigeyuki Toki ◽  
Sureerut Amnuaypornsri ◽  
Adun Nimpaiboon ◽  
Jitladda Sakdapipanich ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Inhomogeneous Material ◽  
Synthetic Analogue ◽  
Stress Strain ◽  
X Ray ◽  
Stress Strain Relation ◽  
Strain Induced Crystallization ◽  
Induced Crystallization ◽  
Flow Induced Crystallization

ABSTRACT Strain-induced crystallization (SIC) and stress–strain relations of varied crosslink structures and varied crosslink densities of vulcanized natural rubber (NR), vulcanized synthetic polyisoprene rubber (IR), and un-vulcanized natural rubber are compared using a synchrotron X-ray. The onset strain of SIC does not depend on crosslink density and crosslink structures. Un-vulcanized NR shows a smaller onset strain of SIC than that of vulcanized NR. Therefore, entanglements in NR are pivot points to induce SIC, just as entanglements in semi-crystalline plastics induce flow-induced crystallization (FIC). During deformation, complicated phenomena occur simultaneously such as cavitation, crosslink breakdown, SIC with temperature upturn, and limited extensibility of chains between crosslinks, because rubber is a significantly inhomogeneous material. It is still difficult to evaluate the contribution of SIC to stress-upturn of the stress–strain relation of rubber.

scholarly journals The Orientation of Strain-Induced Crystallites in Uniaxially-Strained, Thin and Wide Bands Made from Natural Rubber

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 294 ◽  
Author(s):  
Konrad Schneider ◽  
Matthias Schwartzkopf
Keyword(s):  
Natural Rubber ◽  
Pure Shear ◽  
Orientation Distribution ◽  
Thin Strip ◽  
X Ray Diffraction ◽  
Reinforcing Effect ◽  
X Ray ◽  
Crack Tips ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

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.

Kinetics of strain-induced crystallization in natural rubber: A diffusion-controlled rate law

Polymer ◽  
2015 ◽  
Vol 72 ◽  
pp. 52-58 ◽  
Author(s):  
Karsten Brüning ◽  
Konrad Schneider ◽  
Stephan V. Roth ◽  
Gert Heinrich
Keyword(s):  
Natural Rubber ◽  
Rate Law ◽  
Diffusion Controlled ◽  
Strain Induced Crystallization ◽  
Kinetics Of ◽  
Induced Crystallization

INFLUENCE OF STRAIN-INDUCED CRYSTALLIZATION ON STRESS SOFTENING OF SULFUR CROSS-LINKED UNFILLED GUAYULE AND DANDELION NATURAL RUBBERS

2019 ◽  
Vol 92 (2) ◽  
pp. 388-398
Author(s):  
P. Junkong ◽  
Y. Matsushima ◽  
T. Phakkeeree ◽  
K. Cornish ◽  
Y. Ikeda
Keyword(s):  
Natural Rubber ◽  
Cyclic Deformation ◽  
X Ray Diffraction ◽  
Key Factors ◽  
Average Volume ◽  
X Ray ◽  
Stress Softening ◽  
Strain Induced Crystallization ◽  
Stretching Ratio ◽  
Induced Crystallization

ABSTRACT The stress softening behaviors of sulfur cross-linked unfilled guayule natural rubber (S-GR) and sulfur cross-linked unfilled dandelion natural rubber (S-DR) under cyclic deformation were characterized by simultaneous wide angle X-ray diffraction and tensile measurements under cyclic deformation. The behaviors were found to be affected by their strain-induced crystallization (SIC) phenomena and aggregated nonrubber components. The stress softening degree at stretching ratio = 8.0 of S-DR was almost two times larger than that of S-GR. Additionally, the hysteresis loss and residual strain of S-DR were much higher than those of S-GR in the same cycle. The key factors that caused the increase in their degree of stress softening were the increase in average volume and the decrease in average number of strain-induced crystallites upon cyclic deformation, not the insignificant decrease in crystallinity. The breakage of the aggregated nonrubber components is a main origin of stress softening behaviors for S-GR and S-DR because their SIC behaviors also were significantly influenced by the aggregates of nonrubber components in the rubber matrixes. Both the effects of nonrubber components and SIC on stress softening were more dominant in S-DR than in S-GR, probably owing to the larger amount of aggregated nonrubber components in the former than in the latter. The results will be useful in effectively using guayule and dandelion natural rubbers as alternatives to Hevea natural rubber in the rubber industry.

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