Influence of Chemical Structure on the Dynamic Properties of Sulfur-Vulcanized, Carbon Black-Reinforced Natural Rubber

1972 ◽  
Vol 45 (4) ◽  
pp. 1051-1063 ◽  
Author(s):  
G. M. Doyle ◽  
R. E. Humphreys ◽  
R. M. Russell
Keyword(s):  
Service Life ◽  
Carbon Black ◽  
Natural Rubber ◽  
High Temperatures ◽  
Network Structure ◽  
Thermal Aging ◽  
Chemical Structure ◽  
Dynamic Properties ◽  
Rubber Vulcanizate ◽  
Operating Temperatures

Abstract A comparison is made of the composition and properties of the different rubber vulcanizate networks obtained by varying the ratio of sulfur to sulfenamide accelerator and by the thermal aging of vulcanizates containing predominantly polysulfide crosslinks. It is concluded that the changes in network structure which can take place, for example, during the service life of natural rubber tires are not the direct cause of failures of the type associated with rubber fatigue at high temperatures. However, a reduction in the total number of crosslinks can accelerate failure by increasing the amount of heat generated during flexing. More stable networks giving improved resistance to fatigue at high operating temperatures are obtained by the use of higher ratios of accelerator to sulfur than are conventionally employed.

Thermal destruction of carbon black network structure in natural rubber vulcanizate

2011 ◽  
Vol 122 (2) ◽  
pp. 1300-1315 ◽  
Author(s):  
Atsushi Kato ◽  
Toshiya Suda ◽  
Yuko Ikeda ◽  
Shinzo Kohjiya
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Network Structure ◽  
Thermal Destruction ◽  
Rubber Vulcanizate

Longitudinal Cracking in a Carbon Black Filled Natural Rubber Vulcanizate during Chemical Stress Relaxation

1998 ◽  
Vol 71 (2) ◽  
pp. 157-167 ◽  
Author(s):  
G. R. Hamed ◽  
J. Zhao
Keyword(s):  
Stress Relaxation ◽  
Carbon Black ◽  
Natural Rubber ◽  
Longitudinal Crack ◽  
Chemical Stress ◽  
Loading Direction ◽  
Rubber Vulcanizate ◽  
Edge Cracks ◽  
Forced Air ◽  
Oxidative Attack

Abstract Thin specimens of a black-filled, natural rubber vulcanizate have been held in uniaxial tension at 72°C and 200% elongation in a forced air oven. After substantial oxidative attack (inferred from stress relaxation), small edge cracks formed. Initially, these cracks grew perpendicular to the loading direction, but, upon reaching about 0.1 mm in depth, longitudinal crack growth commenced and fracture progressed by a kind of 0°-peel process with “splitting-off” of successive strands of rubber. This phenomenon is attributed to anisotropy in strength caused both by straining and by oxidative attack.

scholarly journals Silica-Reinforced Natural Rubber: Synergistic Effects by Addition of Small Amounts of Secondary Fillers to Silica-Reinforced Natural Rubber Tire Tread Compounds

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Sattayanurak ◽  
J. W. M. Noordermeer ◽  
K. Sahakaro ◽  
W. Kaewsakul ◽  
W. K. Dierkes ◽  
...  
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Dynamic Properties ◽  
Synergistic Effects ◽  
Coupling Reaction ◽  
Rolling Resistance ◽  
High Specific Surface Area ◽  
Pure Silica ◽  
Rubber Compounds ◽  
Wet Grip

Modern fuel-saving tire treads are commonly reinforced by silica due to the fact that this leads to lower rolling resistance and higher wet grip compared to carbon black-filled alternatives. The introduction of secondary fillers into the silica-reinforced tread compounds, often named hybrid fillers, may have the potential to improve tire performance further. In the present work, two secondary fillers organoclay nanofiller and N134 carbon black were added to silica-based natural rubber compounds at a proportion of silica/secondary filler of 45/10 phr. The compounds were prepared with variable mixing temperatures based on the mixing procedure commonly in use for silica-filled NR systems. The results of Mooney viscosity, Payne effect, cure behavior, and mechanical properties imply that the silica hydrophobation and coupling reaction of the silane coupling agent with silica and elastomer are significantly influenced by organoclay due to an effect of its modifier: an organic ammonium derivative. This has an effect on scorch safety and cure rate. The compounds where carbon black was added as a secondary filler do not show this behavior. They give inferior filler dispersion compared to the pure silica-filled compound, attributed to an inappropriate high mixing temperature and the high specific surface area of the carbon black used. The dynamic properties indicate that there is a potential to improve wet traction and rolling resistance of a tire tread when using organoclay as secondary filler, while the combination of carbon black in silica-filled NR does not change these properties.

scholarly journals Carbon Black Network Structure in Natural Rubber Vulcanizates

Seikei-Kakou ◽  
2016 ◽  
Vol 28 (6) ◽  
pp. 210-213
Author(s):  
Atsushi Kato ◽  
Yuko Ikeda ◽  
Shinzo Kohjiya
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Network Structure ◽  
Natural Rubber Vulcanizates
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