Dynamic Properties of Pbna-Natural Rubber Vulcanizates

1968 ◽  
Vol 41 (5) ◽  
pp. 1203-1206 ◽  
Author(s):  
A. R. Payne

Abstract Some crystalline organic compounds containing a β-naphthyl group stiffen rubbers considerably. This paper discusses the dynamic behavior of these systems when subjected to oscillatory strain of increasing amplitude. Modulus strain amplitude plots similar to that in carbon black-natural rubber systems are obtained. The implication of these results to reinforcement theory is discussed.

1999 ◽  
Vol 72 (4) ◽  
pp. 673-683 ◽  
Author(s):  
V. A. Coveney ◽  
D. E. Johnson

Abstract Mathematical modeling of the dynamic behavior of vulcanizates is reviewed with the emphasis on carbon black filled natural rubber (NR). The 3 constant standard triboelastic solid (STS) model and its behavior are described, in general terms and with specific reference to low frequency shear data for a wide range of filled NR vulcanizates. Good general agreement is found between model and experiment for the data obtained at strain amplitudes down to 0.01; there is also acceptably good correlation between carbon black loading and values of STS constants. For previously published data down to very low strain amplitudes (1×10−4), agreement is much less satisfactory.


1963 ◽  
Vol 36 (2) ◽  
pp. 432-443 ◽  
Author(s):  
A. R. Payne

Abstract The dynamic properties of a natural vulcanized rubber containing carbon black were studied for dynamic tensions of amplitude varying greatly. It was shown that both the elastic responses and viscosity change with amplitude of oscillation and with concentration and type of carbon black. The effects of thermal treatment on the dynamic modulus were also studied. Beginning with conditions of equilibrium between the hard and soft regions of the vulcanizate for very weak stresses, the values for the formation of hard regions from soft regions were determined by means of the Van't Hoff isochore.


1973 ◽  
Vol 46 (4) ◽  
pp. 897-926 ◽  
Author(s):  
J. D. Ulmer ◽  
V. E. Chirico ◽  
C. E. Scott

Abstract The influence of carbon black type on the dynamic properties of natural rubber is examined for nine carbon blacks, encompassing a wide range of structure and surface area. The dynamic properties are measured at 23° C and 100° C, over a 2 decade range of log frequency, and over a range of 1 to 25 per cent dynamic strain. The effect of carbon black structure and surface area on dynamic properties of a natural rubber compound are dependent on the combination of strain amplitude and frequency test conditions. The effect of carbon black surface area and structure at different temperatures varies on an absolute basis but not necessarily on a relative basis. Correlations of forced non resonant measurements of dynamic properties with dynamic measurements using other instruments confirms the strain amplitude and frequency interaction with carbon black type. Also, the Goodyear-Healy Rebound machine, the Goodrich Flexometer, and the Pirelli Hysteresimeter can be used to estimate basic dynamic properties over limited strain amplitude and frequency conditions. In addition, mixing procedure was found to have a significant effect on the dynamic properties of a natural rubber compound filled with N-327.


1972 ◽  
Vol 45 (4) ◽  
pp. 1051-1063 ◽  
Author(s):  
G. M. Doyle ◽  
R. E. Humphreys ◽  
R. M. Russell

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
S. Sattayanurak ◽  
J. W. M. Noordermeer ◽  
K. Sahakaro ◽  
W. Kaewsakul ◽  
W. K. Dierkes ◽  
...  

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.


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