The Mechanism of Carbon Black Dispersion in Rubber Compounds Loaded at Practical Level

Asahiro AHAGON; Kazuo MIYASAKA

doi:10.2324/gomu.83.318

Some Initial Trials and Applications of the DFCS Test for Carbon Black Dispersion

Rubber Chemistry and Technology ◽

10.5254/1.3538417 ◽

1997 ◽

Vol 70 (1) ◽

pp. 38-49

Author(s):

G. A. W. Murray ◽

B. H. R. Ng ◽

M. R. Vaseghi Jahromi ◽

D. W. Southwart

Keyword(s):

Standard Deviation ◽

Carbon Black ◽

Normal Distribution ◽

Quantitative Method ◽

Scattered Light ◽

Dark Field ◽

Test Results ◽

Rubber Compounds ◽

Cut Surface ◽

Carbon Black Dispersion

Abstract The Dark Field Cut Surface (DFCS) test is a quantitative method for determining the state of dispersion of carbon black in rubber compounds. The method has been described fully in another paper. Here are reported some of the first applications of the test and some trials that were carried out specifically to investigate and develop the DFCS test. The test is demonstrated to follow accurately the progress of dispersion of carbon black in milled or mixed compounds of NR and SBR. Some tests have been carried out using large batches of test results and these have demonstrated a good fit with a normal distribution. By this means, some recommendations have been derived for suitable sampling rates. The relative merits of the standard deviation and the average for characterizing dispersion have been highlighted. A further way of presenting the results as distribution curves has been demonstrated. A check has been performed to demonstrate that mastication of rubber has little or no influence on the DFCS test results. The DFCS test has been used to give an interesting (provisional) insight to the best ways to operate a rubber mixer. To date, the measured patterns of scattered light show a promising correlation with the anticipated dispersion of carbon black in the specimens tested.

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Carbon Black Dispersion Measurement in Rubber Vulcanizates via Interferometric Microscopy

Rubber Chemistry and Technology ◽

10.5254/1.3547845 ◽

2004 ◽

Vol 77 (4) ◽

pp. 691-710 ◽

Cited By ~ 4

Author(s):

Archie P. Smith ◽

Toni L. Aybar ◽

Ricky W. Magee ◽

Charles R. Herd

Keyword(s):

Carbon Black ◽

Three Dimensional ◽

Dispersion Index ◽

Complete Understanding ◽

Additional Information ◽

Rubber Compounds ◽

Varying Dispersion ◽

Light Beams ◽

Cut Surface ◽

Carbon Black Dispersion

Abstract A new method for characterizing the carbon black dispersion in rubber compounds is introduced. This technique is based on interferometric microscopy (IFM) and utilizes the interference fringes between in-phase light beams reflected from the rubber sample and a smooth reference surface to measure the three-dimensional surface topography. The peaks and valleys present on the fresh-cut surface are representative of the carbon black agglomerates and are used to characterize the dispersion. A series of samples with different base rubbers and varying dispersion levels were created and characterized by both light microscopy and IFM. These results were used to generate a universal dispersion index based on the IFM data that correlates well with the LM dispersion index values. In addition, three-dimensional peak statistics were obtained from the IFM data and used to provide additional information about the carbon black agglomerate distribution. This data can be used for a more complete understanding of the compound behavior as a function of the carbon black dispersion and agglomerate distribution.

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Effect of Processing Additives on Carbon Black Dispersion and Grip Property of High-Performance Tire Tread Compound

Rubber Chemistry and Technology ◽

10.5254/1.3538414 ◽

1997 ◽

Vol 70 (1) ◽

pp. 15-24 ◽

Cited By ~ 11

Author(s):

H. Takino ◽

S. Iwama ◽

Y. Yamada ◽

S. Kohjiya

Keyword(s):

Carbon Black ◽

Viscoelastic Properties ◽

High Performance ◽

Mixing Process ◽

Remarkable Effect ◽

Rubber Compounds ◽

Carbon Black Surface ◽

Black Surface ◽

Power Curves ◽

Carbon Black Dispersion

Abstract Rubber and carbon black compounds show complex behaviors in their mixing process due to their complicated microcomposite structure. Therefore, establishing a clear relationship between the mixing state of the rubber compound and the physical properties of its cured rubber has still remained to be solved in spite of formidable efforts by many rubber technologists. This paper investigated the influence of a processing additive on the carbon black incorporation and its dispersion behavior by inspecting Banbury power curves. From this investigation, we considered that good wettability toward the carbon black surface was necessary for processing additives in order to improve carbon black dispersion. The function of the processing additive was thought to enhance the surface lubrication of carbon black for disagglomeration in the early steps of mixing. The dry grip properties of a tire was estimated from the temperature dependence of dynamic viscoelastic properties of rubber compounds, with improved carbon black dispersion due to the processing additive; and it was confirmed by an actual tire running evaluation. Consequently, we found that tread compounds with improved carbon black dispersion had a remarkable effect on tire dry-grip properties at high temperatures.

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Online Characterization of the Effect of Mixing Parameters on Carbon Black Dispersion in Rubber Compounds Using Electrical Conductivity

Rubber Chemistry and Technology ◽

10.5254/1.3547808 ◽

2004 ◽

Vol 77 (1) ◽

pp. 147-160 ◽

Cited By ~ 15

Author(s):

H. H. Le ◽

S. Ilisch ◽

B. Jakob ◽

H.-J. Radusch

Keyword(s):

Electrical Conductivity ◽

Carbon Black ◽

Mixing Parameters ◽

Rubber Compounds ◽

Mixing Regime ◽

Internal Mixer ◽

Optimal Mixing ◽

Insight Into ◽

Carbon Black Dispersion

Abstract The influences of mixing parameters on the carbon black dispersion can be characterized using the electrical conductivity online measured from internal mixer. As a measure for monitoring the development of carbon black dispersion, a normalized conductivity with regard to the conductivity measured at the BIT (black incorporation time) has been suggested. It is observed that in spite of different mixing parameters, the mixtures possessing the same normalized conductivity factor K/KBIT deliver the same carbon black dispersion and the same mechanical properties. Based on normalized conductivity, a deeper insight into the mixing kinetics can be provided to find an optimal mixing regime.

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