Intrinsic Defects and the Failure Properties of cis-1,4-Polyisoprenes

1996 ◽  
Vol 69 (4) ◽  
pp. 591-599 ◽  
Author(s):  
I. S. Choi ◽  
C. M. Roland
Keyword(s):  
Natural Rubber ◽  
Strain Energy ◽  
Crosslink Density ◽  
Crystallization Behavior ◽  
Inverse Correlation ◽  
Flaw Size ◽  
Dominant Effect ◽  
Strain Induced Crystallization ◽  
Failure Properties ◽  
Induced Crystallization

Abstract Inherent flaw sizes were determined from fatigue lifetimes, and from the crack length dependence of the strain energy to break, for four cis-1,4-polyisoprenes compounded to have the same crosslink density and low strain hysteresis. Both techniques indicated that the flaws intrinsic to guayule rubber (GR), and to a lesser extent conventional natural rubber, are larger than those found in deproteinized NR. This result may not be surprising; however, the failure properties of the elastomers, expected to depend on flaw size, were surprising. The guayule rubber and a natural rubber of relatively low purity (SMR-10) had the highest tensile strengths, tear strengths, breaking energies, and fatigue lifetimes, while DPNR exhibited the worst failure properties. Such an inverse correlation between flaw size and failure performance is due to the dominant effect of strain-induced crystallization. GR and SMR-10 have the highest propensity for strain-induced crystallization, while DPNR is the least strain-crystallizable. Interestingly, all rubbers exhibited the same isotropic crystallization behavior.

scholarly journals Effect of Stretching Rate on Tensile Response and Crystallization Behavior of Crosslinked Natural Rubber

2021 ◽  
Vol 17 (3) ◽  
pp. 217-225
Author(s):  
Abdulhakim Masa ◽  
Nabil Hayeemasae ◽  
Siriwat Soontaranon ◽  
Mohd Hanif Mohd Pisal ◽  
Mohamad Syahmie Mohamad Rasidi
Keyword(s):  
Stress Response ◽  
Natural Rubber ◽  
Deformation Rate ◽  
Crystallization Behavior ◽  
Tensile Deformation ◽  
Chain Orientation ◽  
Tensile Response ◽  
Lower Strain ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

The performance of natural rubber (NR) relies heavily on the microstructural changes during deformation. This has brought to significant change in the stress response of NR. Besides, the stretching rate may also affect the stress response of NR. In this study, effects of stretching rate on tensile deformation and strain-induced crystallization of crosslinked NR were investigated. Results indicated that increasing the strain rate has increased the stress at given strain where the onset of strain-induced crystallization was shifted to a lower strain. The crystallinity of the crosslinked NR was shown to be higher at a high stretching rate and it corresponded well with the tensile response. The results clearly confirm that chain orientation and crystallization became stronger with increasing deformation rate. The study also suggests that the deformation could improve distribution of crosslinked network structures.

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.

Strain-induced crystallization behavior of phenolic resin crosslinked natural rubber/clay nanocomposites

2015 ◽  
Vol 132 (39) ◽  
pp. n/a-n/a ◽  
Author(s):  
Abdulhakim Masa ◽  
Sougo Iimori ◽  
Ryota Saito ◽  
Hiromu Saito ◽  
Tadamoto Sakai ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Crystallization Behavior ◽  
Phenolic Resin ◽  
Clay Nanocomposites ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Comparative Study on Strain-Induced Crystallization Behavior of Peroxide Cross-Linked and Sulfur Cross-Linked Natural Rubber

2008 ◽  
Vol 41 (15) ◽  
pp. 5876-5884 ◽  
Author(s):  
Yuko Ikeda ◽  
Yoritaka Yasuda ◽  
Kensuke Hijikata ◽  
Masatoshi Tosaka ◽  
Shinzo Kohjiya
Keyword(s):  
Comparative Study ◽  
Natural Rubber ◽  
Crystallization Behavior ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Strain-induced crystallization behavior of natural rubber and trans-1,4-polyisoprene crosslinked blends

2010 ◽  
Vol 120 (3) ◽  
pp. 1346-1354 ◽  
Author(s):  
Liangliang Qu ◽  
Guangsu Huang ◽  
Yijing Nie ◽  
Jinrong Wu ◽  
Gengsheng Weng ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Crystallization Behavior ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Strain-induced crystallization behaviour of natural rubbers from guayule and rubber dandelion revealed by simultaneous time-resolved WAXD/tensile measurements: indispensable function for sustainable resources

RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 95601-95610 ◽  
Author(s):  
Yuko Ikeda ◽  
Preeyanuch Junkong ◽  
Takumi Ohashi ◽  
Treethip Phakkeeree ◽  
Yuta Sakaki ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Crystallization Behaviour ◽  
Time Resolved ◽  
Sustainable Resources ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Guayule and rubber dandelion natural rubbers are useful alternatives forHeveanatural rubber in terms of their strain-induced crystallization behaviours.

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