Breakage of Rubber-Filler Linkages and Energy Dissipation in Stressed Rubber

1955 ◽  
Vol 28 (2) ◽  
pp. 540-556
Author(s):  
A. F. Blanchard
Keyword(s):  
Tensile Strength ◽  
Energy Dissipation ◽  
Carbon Black ◽  
Filler Particle ◽  
Particle Diameter ◽  
Interfacial Area ◽  
Synthetic Rubber ◽  
Common Distribution ◽  
Energy Dissipated ◽  
Rubber Filler

Abstract The marked softening of reinforced rubber by applied stress can be interpreted in terms of a range of strengths of secondary linkages formed by rubber-filler attachments, and this can be described by one common distribution parameter K for several grades and types of filler in natural rubber, and also for at least one type of carbon black in Krylene (GR-S) synthetic rubber. Linkages of this type are of little significance in reinforcement, judged by tensile strength or abrasion resistance. The fact that the filler particle diameter had no influence in these experiments on the energy dissipated in breaking secondary linkages, or their number as reflected by their stiffening action, may be considered a serious objection to the presumption that specific surface or interfacial area determines linkage formation in rubber and, hence (supposedly), the reinforcement. There is evidence of primary (strong) linkages introduced by carbon blacks, and these are likely to have a more important role in determin- ing the breaking, tearing, and abrasion of rubber.

Effect of Diameter and Surface Area of Carbon Black Particles on Certain Properties of Rubber Compounds

1944 ◽  
Vol 17 (2) ◽  
pp. 451-474
Author(s):  
D. Parkinson
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Carbon Black ◽  
Abrasion Resistance ◽  
Particle Diameter ◽  
Stiffness Modulus ◽  
Carbon Structures ◽  
Rubber Compounds ◽  
Regular Manner ◽  
Tear Resistance

Abstract Carbon blacks can be grouped into different classes according to the way in which their fineness of division relates to different properties in rubber. Within any one class the principal properties vary in a regular manner with particle size. The normal class consists of the furnace carbons, Kosmos (Dixie)-40, Statex, the rubber-grade impingement carbons, and possibly, the color-grade impingement carbons. The subnormal classes consist of thermal carbons and acetylene and lamp blacks. Irrespective of the above classification, the properties which depend more on fineness of division than on other factors are rebound resilience, abrasion resistance, tensile strength and tear resistance. The lower limit of particle diameter for best tensile strength and tear resistance appears to be higher than that for abrasion resistance. B.S.I, hardness and electrical conductivity are properties which depend at least as much on other factors as on particle size. Stiffness (modulus) depends more on other factors than on particle size. Factors modifying the effects of particle size (or specific surface) include the presence of carbon-carbon structures and a reduction in strength of bond in rubber-carbon structures. Carbon black is thought to exist in rubber in four states: agglomerated, flocculated, dispersed, and bonded to the rubber molecules (the reënforcing fraction). Abrasion resistance is regarded as providing the only reliable measure of reënforcement.

The Mechanism of Reënforcement of Elastomers by Pigments

1948 ◽  
Vol 21 (3) ◽  
pp. 667-681 ◽  
Author(s):  
Leonard H. Cohan
Keyword(s):  
Calcium Carbonate ◽  
Carbon Black ◽  
Volume Concentration ◽  
Particle Diameter ◽  
Cross Linking ◽  
Average Particle ◽  
Average Particle Diameter ◽  
A Value ◽  
Synthetic Rubber ◽  
Similar Equation

Abstract Modulus appears to be independent of average particle diameter. With respect to the dependence of modulus on loading, calcium carbonate pigments which are symmetrical follow the equation derived by Guth and Gold for the relation between modulus and volume concentration of symmetrical inelastic particles. Up to about 80 parts by weight loading, HMF black follows a similar equation derived for rod-shaped particles, assuming a value of six for the ratio of the length to the diameter of the particles. The agreement with these theoretical equations is surprisingly good, and holds out the eventual possibility of calculating modulus over a wide loading range from tests at a single loading. Hardness and plasticity increase with loading in qualitative agreement with the equations. The behavior of modulus as a function of loading and average particle diameter of pigments indicates that vulcanized natural or synthetic rubber is not adsorbed in appreciable quantities or with sufficient force to be rendered inelastic at the surface of either calcium carbonate or carbon black pigments. Qualitative predictions based on the hypothesis that tensile strength is a measure of the force required to separate rubber chains from each other rather than to break rubber chains, and that pigment particles act as cross-linking agents holding the chains together, are in agreement with the behavior of calcium carbonate and carbon black pigments of widely different surface area over a considerable loading range.

Role of Particle Diameter and Linkage Formation in Rubber Reinforcement

1956 ◽  
Vol 29 (4) ◽  
pp. 1284-1299
Author(s):  
A. F. Blanchard
Keyword(s):  
Wear Resistance ◽  
Abrasion Resistance ◽  
Filler Particle ◽  
Particle Diameter ◽  
Interfacial Area ◽  
Filler Concentration ◽  
Stress Strain ◽  
Strain Measurements ◽  
Carbon Blacks ◽  
Molecular Dimensions

Abstract Fillers with little effect on abrasion resistance differ further from carbon blacks in having little or no tendency to introduce some form of strong-type linkage which could sitffen and strengthen the rubber at high extensions. Such linkages are here termed primary to distinguish them from secondary (weak-type) linkages, which have a range of lower strengths as revealed by breakage with applied stress, and contribute little to reinforcement. The abrasion resistance for a given filler concentration is much improved even by remarkably small numbers of primary linkages if the particles are sufficiently small; and it is comparatively insensitive to the number of primary linkages in the quantities normally obtained with carbon blacks. For instance, a considerable degree of reinforcement is obtained with the partially graphitized black known as Graphon, although this black shows drastically reduced capacity to form linkages and little change in particle diameter. The large differences in the wear resistance of vulcanizates containing different grades of carbon black must therefore be attributed mainly to the particle diameter itself rather than to the linkages formed. Moreover, primary linkages as reflected by stress-strain measurements could not explain the effect of particle diameter on reinforcement because they are unrelated to particle diameter. For good wear resistance the particles probably need to have macro-molecular dimensions, though small. To regard the effect of particle diameter in terms of the interfacial area for linkage formation is inconsistent with the above conclusions. For a given dispersion and concentration of filler it is suggested that reinforcement is most likely to find proper expression in terms of the number of linkages per particle and the number of particles. This is expressed mathematically in a tentative, empirical form of equation designed to fit general conceptions, and to correlate roughly the abrasion resistance with filler particle diameter and with primary linkages as reflected by stress-strain measurements. The equation implies that reinforcement increases with diminishing particle diameter until an optimum is reached, and thereafter decreases to become negligible for particles of molecular dimensions.

Tensile Properties of Natural and Synthetic Rubbers at Elevated and Subnormal Temperatures

1950 ◽  
Vol 23 (2) ◽  
pp. 338-346 ◽  
Author(s):  
B. S. T. T. Boonstra
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Carbon Black ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Temperature Strength ◽  
Synthetic Rubber ◽  
Natural And Synthetic

Abstract It is necessary to determine the physical properties of rubbers at relatively high temperatures when products made from them are to be used at such temperatures in actual service. The term heat aging is used when the vulcanizate is tested at room temperature, exposed to elevated temperatures for given periods of time, and then tested again at room temperature. The term high-temperature strength is proposed for values obtained when the vulcanizates are tested at the actual higher service temperatures. Effective comparison of natural and synthetic rubbers is best obtained by determining tensile product values, which are the result of the combining of tensile strength and elongation values. In the evaluating of vulcanizates of tire compounds of various rubbers, another factor must be taken into account. Synthetic-rubber tires develop more heat in service than do natural-rubber tires, and the former therefore generally operate at higher temperatures than do the latter. Synthetic-rubber tires therefore require a greater high temperature strength than do natural rubber tires, but, as has been shown, synthetic rubbers actually have a lower high-temperature strength. The part played by carbon black with respect to the tensile properties of some synthetic rubbers is considered that of a substitute for crystallization in natural and other synthetic rubbers, which substitute does not, however, possess the same favorable features. Carbon black even in noncrystallizing rubbers does not increase strength; it merely shifts the optimum strength value to a higher temperature so that this temperature is in the room temperature range. The temperature coefficient of strength for Butyl and Neoprene rubbers is so large at room temperature that a few degrees' difference in temperature causes large changes in strength. The tensile strength and elongation at break of these two rubbers decrease sharply between 20 and 40° C.

Light Phenomena on Elongating Vulcanized Rubbers

1950 ◽  
Vol 23 (2) ◽  
pp. 332-337
Author(s):  
A. Van Rossem
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Carbon Black ◽  
Barium Sulfate ◽  
High Speed ◽  
Filler Particle ◽  
Light Effect ◽  
Dark Room ◽  
Rubber Filler

Abstract A description is given of a light phenomenon, first observed by W. C. Smith, when carrying out tear tests on some loaded vulcanized rubbers in a dark room. This phenomenon has been studied more systematically by high-speed extension tests. It appears that this light effect has nothing to do with the choice of accelerators, but with the compounding ingredients of loaded vulcanized rubbers. In general, those compounding ingredients which belong to the filler class, such as whiting, talc, and ground barium sulfate, show this light phenomenon very distinctly, while vulcanized rubbers with reinforcing compounding ingredients, such as zinc oxide, titanium dioxide, and carbon black, do not show any light effect when quickly extended. In accordance with this, Kalite and Calcene, which behave as reinforcing compounding ingredients, do not show any light phenomenon. It seems probable, that, on elongating the vulcanized rubbers containing fillers, the adhesion of rubber-filler particle is broken, and electrical charges appear on an extremely large surface, which lead to innumerable discharges into surrounding vacuoles, causing the general light phenomenon observed.

Carbon Blacks in GR-S

1946 ◽  
Vol 19 (1) ◽  
pp. 100-122 ◽  
Author(s):  
D. Parkinson
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Carbon Blacks ◽  
Styrene Copolymer ◽  
Synthetic Rubber ◽  
First Approximation ◽  
Different Types ◽  
Almost All ◽  
Butadiene Styrene

Abstract The importance of different types of colloidal carbon as reinforcing agents for the butadiene-styrene copolymer, GR-S, has been stressed in recent papers. It has been shown that, to a first approximation, the effect of carbon blacks in this type of synthetic rubber is similar to that in natural rubber, but it has been shown also that the extremely low tensile strength and poor tearing properties of uncompounded vulcanized GR-S necessitates the addition of some form of carbon black to almost all types of compounds. The present paper considers the influence of carbon blacks in vulcanized GR-S compounds. Earlier papers have discussed the effect of carbon blacks in natural rubber.

Hyperelastic models for the description and simulation of rubber subjected to large tensile loading

2021 ◽  
Vol 2 (108) ◽  
pp. 75-85
Author(s):  
Q.H. Jebur ◽  
M.J. Jweeg ◽  
M. Al-Waily ◽  
H.Y. Ahmad ◽  
K.K. Resan
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Tensile Test ◽  
Accurate Description ◽  
Percentage Error ◽  
Relative Percentage ◽  
Elastomeric Material ◽  
Tensile Data ◽  
Relative Percentage Error ◽  
Hyperelastic Models

Purpose: Rubber is widely used in tires, mechanical parts, and user goods where elasticity is necessary. Some essential features persist unsolved, primarily if they function in excessive mechanical properties. It is required to study elastomeric Rubber's performance, which is operational in high-level dynamic pressure and high tensile strength. These elastomeric aims to increase stress breaking and preserve highly pressurised tensile strength. Design/methodology/approach: The effects of carbon black polymer matrix on the tensile feature of different Rubber have been numerically investigated in this research. Rubber's material characteristics properties were measured using three different percentages (80%, 90%and 100%) of carbon black filler parts per Hundreds Rubber (pphr). Findings: This study found that the tensile strength and elongation are strengthened as the carbon black filler proportion increases by 30%. Practical implications: This research study experimental tests for Rubber within four hyperelastic models: Ogden's Model, Mooney-Rivlin Model, Neo Hooke Model, Arruda- Boyce Model obtain the parameters for the simulation of the material response using the finite element method (FEM) for comparison purposes. These four models have been extensively used in research within Rubber. The hyperelastic models have been utilised to predict the tensile test curves—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model—the accurate description and prediction of elastomer rubber models. For four models, elastomeric material tensile data were used in the FEA package of Abaqus. The relative percentage error was calculated when predicting fitness in selecting the appropriate model. Numerical Ogden model results have shown that the relative fitness error was the case with large strains are from 1% to 2.04%. Originality/value: In contrast, other models estimate parameters with fitting errors from 2.3% to 49.45%. The four hyperelastic models were tensile test simulations conducted to verify the efficacy of the tensile test. The results show that experimental data for the uniaxial test hyperelastic behaviour can be regenerated effectively as experiments. Ultimately, it was found that Ogden's Model demonstrates better alignment with the test data than other models.

Fluoroelastomer Applications for Pollution Control in the Automotive, Petrochemical, and Electric Power Industries

1982 ◽  
Vol 55 (4) ◽  
pp. 1137-1151 ◽  
Author(s):  
R. R. Campbell ◽  
D. A. Stivers ◽  
R. E. Kolb
Keyword(s):  
Tensile Strength ◽  
Sulfuric Acid ◽  
Carbon Black ◽  
Pollution Control ◽  
Acid Resistance ◽  
Organic Peroxide ◽  
Exposed Surface ◽  
Chemical Attack ◽  
Temperature Ranges ◽  
Concentrated Sulfuric Acid

Abstract The effects of percent fluorine, filler, and cure systems on the thermal and acid resistance of fluoroelastomers were evaluated over temperature ranges that would be typical of actual flue duct installations and accelerated conditions such as 275°C for thermal resistance and 149°C for concentrated sulfuric acid resistance. FKM 2176, which contains 65% fluorine by weight, became hard and brittle after two weeks of accelerated air aging at 275°C. The balance of physical properties of FKM 2176 were good when aged at 200°C. FKM 4894, which contains 67% fluorine by weight, retained useful properties after six weeks of accelerated air aging at 275°C. This indicates this material has improved properties for flue duct applications compared to FKM 2176. FKM 4894 filled with MT carbon black had improved retention of tensile strength after aging at 232°C relative to the FKM 4894 filled with SRF/HAF black, Austin Black and litharge. FKM 2176 was totally degraded after aging three days at 149°C in concentrated sulfuric acid. Aging of FKM 4894 in concentrated sulfuric acid at 149°C resulted in a loss of approximately 75 percent of the original tensile and an increase in the elongation, and the appearance of the exposed surface did not indicate chemical attack. Although FKM 4894 was superior to FKM 2176 when aged in sulfuric acid at 149°C, there was little difference between FKM 4894 and FKM 2176 when aged at 121 °C for up to four weeks or after eight weeks at 100°C in concentrated sulfuric acid. Austin Black showed the best retention of tensile of the four filler systems evaluated after aging at 100°C in concentrated sulfuric acid. FKM 4826, which contains 69% fluorine and is vulcanized using organic peroxide and triallyl isocyanurate, has indicated a compatibility with fiberglass that is superior to all fluorocarbon elastomer gums that were tested.

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