The Heat Conductivity of Rubber

1940 ◽  
Vol 13 (2) ◽  
pp. 361-374 ◽  
Author(s):  
L. S. Frumkin ◽  
Yu B. Dubinker
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Temperature Change ◽  
Heat Conductivity ◽  
Carbon Blacks ◽  
Increase With Increase ◽  
Vulcanization Process

Abstract 1. In rubber technology, the important factor is the heat conductivity of rubber mixtures, which is characterized by the rate of temperature change of the inner layers. 2. The method proposed makes it possible to compare the heat conductivities of rubber mixtures. 3. The heat conductivities of all types of rubber mixtures increase with increase in temperature. 4. Addition of zinc oxide in the usual proportions decreases the heat conductivity of mixtures containing no carbon black; in mixtures containing carbon blacks the addition of zinc oxide increases slightly their heat conductivty. It follows that the addition of zinc oxide for the acceleration of the vulcanization process has an insignificant influence on thermal conductivity. 5. With increasing additions of carbon black up to 25 per cent by weight of the rubber mixtures result the heat conductivity increases; but with further increases in the percentage of carbon blacks the heat conductivity decreases. 6. Rubber mixtures of the same composition but containing different kinds of carbon black show different heat conductivities. The lowest heat conductivity was found in rubber mixtures containing P-33 carbon black, followed in increasing order of heat conductivity by mixtures with Mai˘kop, Gastex, Thermax, Kudinov and Yaroslav carbon blacks. Thus lampblacks have a greater effect on the heat conductivity of rubber mixtures than do gas blacks.

Investigation of the Thermal Conductivity of Rubber

1938 ◽  
Vol 11 (2) ◽  
pp. 359-371 ◽  
Author(s):  
L. Frumkin ◽  
Yu Dubinker
Keyword(s):  
Thermal Conductivity ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Natural Rubber ◽  
Considerable Increase ◽  
Large Percentage ◽  
K Value ◽  
Synthetic Rubber ◽  
Coefficient Of Thermal Conductivity

Abstract 1. The apparatus for the determination of the coefficients of thermal conductivity which is described is satisfactory for the investigation of rubber mixtures. 2. A review of the results of the determinations of K values of various mixtures leads to the following conclusions: (a) The thermal conductivity of rubber mixtures containing synthetic rubber is greater than that of mixtures containing natural rubber. (b) The addition of zinc oxide even in considerable quantities to rubber mixtures containing a large percentage (55 per cent) of carbon black does not substantially increase thermal conductivity. (c) In the case of carcass mixtures a considerable increase in the coefficient of thermal conductivity is observed when the content of zinc oxide is increased from 7.5 to 15 per cent by weight; on further increase in the zinc oxide K increases but little. (d) The K value of carcass mixtures before vulcanization is smaller than that of the same mixtures after vulcanization by an average of 23 per cent. (e) The thermal conductivity of uncured tread mixtures is the same as that of vulcanized mixtures. (f) The coefficient of vulcanization has no effect on the K value of unloaded mixtures and mixtures containing fillers. (g) The K value of rubber mixtures increases sharply with addition up to 60 per cent by volume of fillers with good thermal conductivity (zinc oxide and graphite), but only slowly with the addition of fillers of medium thermal conductivity (carbon black). In other words, the curve of the relation between the coefficient of thermal conductivity and the percentage by volume of graphite and of zinc oxide is convex to the filler axis and is concave in the case of carbon black.

Some Observations on Carbon Black

1930 ◽  
Vol 3 (1) ◽  
pp. 111-121
Author(s):  
C. M. Carson ◽  
L. B. Sebrell
Keyword(s):  
Zinc Oxide ◽  
Carbon Black ◽  
Adsorptive Capacity ◽  
Carbon Blacks ◽  
Vulcanized Rubber ◽  
Rubber Cement

Abstract Different carbon blacks have certain definite effects upon the vulcanized rubber stocks with which they are mixed. The experiments described herein may be grouped under four main heads: (1) adsorption, (2) effect of heat, (3) reaction with sulfur and zinc oxide, and (4) dispersion or rate of settling. The adsorptive capacity of the black is a measure of the rate of cure of the rubber mix, low-adsorptive blacks giving a faster curing stock than high-adsorptive blacks. An indication of the stiffening action of a carbon black may be secured by measuring the amount of carbon dispersed in a thin rubber cement which cannot be centrifuged out in a given time. The effect of temperatures from 500° to 1200° C. on carbon blacks is to render them highly adsorptive and also to give a rubber mix which cures faster and has a higher modulus. The reaction of carbon blacks with sulfur and zinc oxide in boiling xylene liberates a substance having accelerating properties in a pure gum mix.

Measurement of Average Particle Size of Fine Pigments

1932 ◽  
Vol 5 (2) ◽  
pp. 202-215 ◽  
Author(s):  
S. D. Gehman ◽  
T. C. Morris
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Wave Length ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Carbon Blacks ◽  
Count Method

Abstract A method of obtaining excellently dispersed suspensions of rubber pigments of accurate concentration is described in which the pigment is milled into rubber and the stock then dissolved in a solvent. The average particle sizes of carbon blacks measured by the Zsigmondy count method were found to range from 0.061μ for rubber gas black to 2.22μ for the coarsest one measured. The zinc oxide pigments had average particle sizes from 0.076μ to 0.57μ.. Measurements on several other pigments of interest are included. Because of the high visibility in the ultra-microscope, this method gives smaller values for average particle size than the photomicrographic methods. The results have been used to calibrate a microturbidimeter of the extinction type for use in measuring average particle size. Curves are included showing how the turbidities of suspensions of zinc oxide and carbon black vary with the average particle size, concentration, and wave length of light used.

Carbon Blacks and Their Use in Rubber. III—Aging Effects

1928 ◽  
Vol 1 (3) ◽  
pp. 475-484
Author(s):  
L. B. Cox ◽  
C. R. Park
Keyword(s):  
Zinc Oxide ◽  
Carbon Black ◽  
Stearic Acid ◽  
Weight Increase ◽  
Aging Effects ◽  
Carbon Blacks ◽  
Aging Properties ◽  
Good Agreement

Abstract The aging properties of compounded rubber stocks are affected by the carbon black which is used. The order of increasing superiority for the blacks tried is Super Spectra, Micronex, Charlton, Goodwin, and Thermatomic. The order of increasing superiority of accelerators is diphenylguanidine, hexamethylenetetramine, ethylidene-aniline, mercaptobenzothiazole. The last two are put in this order mainly because of the inferior original properties of ethylidene-aniline. Results of tensile, abrasion, and weight increase tests are in reasonably good agreement. The effect of acidity in any compounding material is neutralized in a stock containing zinc oxide. Stearic acid is without effect upon aging properties of cured rubber.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

DISCUSSION ABOUT THERMAL CONDUCTIVITY OF CARBON BLACK FILLED RUBBER

2015 ◽  
Vol 6 (2) ◽  
pp. 159-172 ◽  
Author(s):  
Junping Song ◽  
Lianxiang Ma ◽  
Yan He ◽  
Wei Li ◽  
Shi-Chune Yao
Keyword(s):  
Thermal Conductivity ◽  
Carbon Black ◽  
Filled Rubber

Ionic Crosslinking of Carboxylated SBR

1983 ◽  
Vol 56 (5) ◽  
pp. 942-958 ◽  
Author(s):  
Kyosaku Sato
Keyword(s):  
Zinc Oxide ◽  
Carbon Black ◽  
Elevated Temperatures ◽  
Ion Clusters ◽  
Ionic Crosslinking ◽  
Reinforcing Fillers ◽  
Ionic Bonds ◽  
Tan Δ ◽  
And Shifts ◽  
Ionic Crosslinks

Abstract 1. Ionic bonding of carboxylated SBR with zinc oxide is detectable by means of measurements of the temperature dependence of tan δ. There is an α peak in the region of 60°C at 3.5 Hz. The position and shape of the α peak are strongly dependent on the state of cure of the vulcanizates. Without permanent crosslinking, the α peak is a plateau; as the crosslink density increases, the α peak becomes sharper and shifts to lower temperatures. The presence of carbon black causes the α peak to shift to higher temperatures, regardless of the presence of permanent crosslinks. 2. Ionic bonds in carboxylated SBR reacted with zinc oxide are in the form of ion clusters which function as crosslinks at room temperature. The ionic crosslinks provide carboxylated SBR with high tensile strength in the absence of reinforcing fillers. The presence of carbon black causes the 300% modulus to increase. The ionic crosslinks are labile, and the strength is lost at moderately elevated temperatures. A mixed cure system consisting of both sulfur and zinc oxide provides higher heat resistance than either of the single cure systems.

Stochastic Analysis of Temperature Distribution in a Solid With Random Heat Conductivity

1988 ◽  
Vol 110 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Da Yu Tzou
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Heat Conductivity ◽  
Stochastic Analysis ◽  
Solid Medium ◽  
Mean Value ◽  
Random Response ◽  
Thermal Failure ◽  
Numerical Examples ◽  
The Mean

Stochastic temperature distribution in a solid medium with random heat conductivity is investigated by the method of perturbation. The intrinsic randomness of the thermal conductivity k(x) is considered to be a distribution function with random amplitude in the solid, and several typical stochastic processes are considered in the numerical examples. The formulation used in the present analysis describes a situation that the statistical orders of the random response of the system are the same as those of the intrinsic random excitations, which is characteristic for the problem with extrinsic randomness. The maximum standard deviation of the temperature distribution from the mean value in the solid medium reveals the amount of unexpected energy experienced by the solid continuum, which should be carefully inspected in the thermal-failure design of structures with intrinsic randomness.

Orthogonal Experiment Analysis of Mechanical Thermal Conductivity on Multi-Component Fillers

2013 ◽  
Vol 753-755 ◽  
pp. 2379-2382
Author(s):  
Shi Meng Xu ◽  
Run Bo Ma ◽  
Jian Hua Du ◽  
Jun Hong Liu ◽  
Qi Jin
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Carbon Black ◽  
Orthogonal Experiment ◽  
Experiment Design ◽  
Rubber Composites ◽  
Orthogonal Experiment Design ◽  
Rubber Composite ◽  
Al Powder ◽  
Experiment Analysis

Filled the N330 carbon black, silica T80 carbon black and Al powder and Fe2O3 magnetic nanoparticles, the rubber composites on multi-component electromagnetic fillers were prepared according to orthogonal experiment analysis, and the preliminary experiment conclusions of the filler prescription designs were given; Based on the experiment design, the mechanical properties and thermal conductivity of the rubber composite were tested, and the testing results were analyzed by using variance analysis. Thus, the paper shows that the effects of N330 on rubber mechanical properties are significant, and the effects of Al powder on the rubber thermal conductivity are significant. Moreover, it is highly emphasized in this paper that the orthogonal experiment design must be carefully explored before the tests are executed.

A Carbon Black Structure-Concentration Equivalence Principle. Application to Stress-Strain Relationships of Filled Rubbers

1971 ◽  
Vol 44 (1) ◽  
pp. 199-213 ◽  
Author(s):  
Gerard Kraus
Keyword(s):  
Carbon Black ◽  
Primary Structure ◽  
Equivalence Principle ◽  
Chemical Activity ◽  
Cross Linking ◽  
Surface Chemical ◽  
Deformation Structure ◽  
Carbon Blacks ◽  
Filled Rubbers ◽  
Dependent Factor

Abstract It is shown that various modulus values of carbon black reinforced rubber are functions of the product of the actual black loading and a structure dependent factor. The structure factor appears to be a linear function of the so-called 24M4 value of the dibutylphthalate absorption and is independent of elongation, temperature, and degree of cross-linking over the ranges covered by the data reported. An interpretation of the results is offered based on the idea of polymer occluded in the interstices of primary structure aggregates and thereby shielded from deformation. Structure-concentration equivalence can only be demonstrated with carbon blacks differing in (primary) structure alone. Deviations are observed whenever the carbon blacks compared vary significantly in specific surface area and surface chemical activity.

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