Changes of Electrical Resistance of Rubbers Loaded with Carbon Black

1957 ◽  
Vol 30 (2) ◽  
pp. 572-583
Author(s):  
D. G. Marshall
Keyword(s):  
Experimental Investigation ◽  
Carbon Black ◽  
Natural Rubber ◽  
Electrical Resistance ◽  
Current Flow ◽  
Electrical Contact ◽  
Butyl Rubber ◽  
Initial Increase ◽  
Electrically Conducting ◽  
Conducting Rubber

Abstract Many workers have studied the changes in resistivity that occur on deforming rubbers loaded with carbon black. This paper describes three types of experimental investigation that do not seem to have received detailed study previously, and also a theory that explains the results qualitatively in terms of variations of contact resistances between carbon black particles. Firstly, the changes of resistance of vulcanized natural rubber, Butyl rubber, Neoprene, and Thiokol FA loaded with carbon black have been studied during cyclic deformations. Secondly, the initial increase of resistance during stretching testpieces of vulcanized natural rubber containing several loadings of different carbon blacks has been investigated. Finally, the changes of resistance with time that occur after stretching and releasing samples of electrically conducting rubber have been studied. The ingredients and preparation of the compounds used in experiments discussed in this paper are listed in the Appendix. The testpieces used in the following experiments were approximately 0.7 cm. wide, 0.1 cm. thick, and 7.0 cm. long. Electrical contact was established by means of brass strips bonded by molding into the ends of the samples, so that the direction of current flow was along the length of the pieces, and in the same direction as the extensions.

Heats of Vulcanization of Synthetic Rubbers

1944 ◽  
Vol 17 (2) ◽  
pp. 404-411 ◽  
Author(s):  
P. L. Bruce ◽  
R. Lyle ◽  
J. T. Blake
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Chemical Reactions ◽  
Side Reaction ◽  
Heat Evolution ◽  
Butyl Rubber ◽  
Vulcanized Rubber ◽  
Principal Reaction ◽  
Low Sulfur ◽  
Quantity Of Heat

Abstract 1. The heats of vulcanization for natural rubber and Buna-S are nearly equal. The data for both materials indicate two different chemical reactions during vulcanization. At low sulfur percentages, the principal reaction forms soft vulcanized rubber and is accompanied by little or no heat evolution. Above the 2 per cent sulfur region, a second reaction predominates, forming hard rubber and producing a relatively large quantity of heat. 2. The presence of an accelerator (Santocure) in Buna-S has little, if any, effect on heat of vulcanization. 3. The addition of carbon black to Buna-S lowers the heat of vulcanization in the region above 4 per cent sulfur. The calories evolved in a 10 per cent sulfur compound decrease linearly with percentage of carbon black. 4. The heats of vulcanization of Buna-N (Hycar OR-15) indicate the presence of two chemical reactions. Unlike natural rubber and Buna-S, the ebonite reaction does not predominate until the sulfur concentration is raised above 10 per cent. 5. The heat of vulcanization of Butyl rubber with sulfur is equal to the heat evolved with natural rubber containing 0.6 per cent sulfur. If one sulfur atom reacts per double bond, the maximum amount combining would be 0.72 per cent sulfur. During the vulcanization of Butyl rubber with p-quinone dioxime and lead peroxide, a large amount of heat is evolved by a side reaction between the vulcanizing agents. The reaction involving the Butyl rubber produces about 6 calories per gram, a considerably higher value than the 1 calorie produced by sulfur vulcanization. 6. The heat of vulcanization of Neoprene-GN without added agents corresponds to a value for smoked sheet rubber containing 4.5 per cent sulfur. The addition of zinc oxide and magnesia decreases the heat of vulcanization.

scholarly journals Study the impact of A nanomixture of carbon black and clay on the mechanical properties of A series of irradiated natural rubber/ butyl rubber blend

2021 ◽  
Author(s):  
Dalal Alshangiti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Theoretical Models ◽  
Butyl Rubber ◽  
Nano Particles ◽  
Vinyl Silane ◽  
Link Density ◽  
The Impact

Abstract A series of natural rubber/ butyl rubber NR/IIR blend loaded with N660 carbon black CB and triethoxy vinyl silane treated clay nano particles (TCNP) were prepared using gamma irradiation in the presence of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). The effect of incorporating different content of N660 carbon black and 5 part per hundred of rubber (phr) of treated clay on the mechanical properties of the prepared nano composites have been investigated. The additions of TCNP into CB/ rubber composites markedly increase their tensile strength due to the increase of the cross-link density. These results indicated that the TCNP may be enclosed or trapped in the occluded structure of CB. The effect of CB and TCNP content on the tensile strength (σ), elongation at break (εb %) and modulus of elasticity (E, MPa) of natural rubber/ butyl rubber NR/IIR blend have been investigated. The incorporation of 5 phr of TCNP into 30 phr carbon black loaded NR/ IIR composites results in the increased tensile strength value by about 60%. Finally, theoretical models were used to interpret the experimental results.

Experimental investigation and modelling of compressibility induced by damage in carbon black-reinforced natural rubber

2014 ◽  
Vol 342 (5) ◽  
pp. 299-310 ◽  
Author(s):  
Sabine Cantournet ◽  
Khaled Layouni ◽  
Lucien Laiarinandrasana ◽  
Roland Piques
Keyword(s):  
Experimental Investigation ◽  
Carbon Black ◽  
Natural Rubber

Improvement of the Functionalities of Natural Rubber/Cellulose Composites Using Epoxidized Natural Rubber

2015 ◽  
Vol 1110 ◽  
pp. 51-55
Author(s):  
Kunihiro Araki ◽  
Syonosuke Kaneko ◽  
Koki Matsumoto ◽  
Asahiro Nagatani ◽  
Tatsuya Tanaka ◽  
...  
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Barrier Properties ◽  
Vibration Damping ◽  
Butyl Rubber ◽  
Epoxidized Natural Rubber ◽  
Green Composite ◽  
Gas Barrier ◽  
Barrier Materials ◽  
Cellulose Composites

We investigated the efficient use of cellulose to resolve the problem of the depletion of fossil resources. In this study, as the biomass material, the green composite based on natural rubber (NR) and the flake-shaped cellulose particles (FSCP) was produced. Moreover, in order to improve vibration-damping and O2barrier properties, NR and epoxidized natural rubber (ENR) blends were also used. In addition, butyl rubber (IIR) was used as a target of damping or gas-barrier materials. Vibration-damping and O2barrier properties of the composite including FSCP was increased with increasing ENR content. In particular, we found that ENR-50 composite containing 50 phr FSCP has higher vibration-damping property than IIR composite containing 50 phr carbon black.

Electrical conduction hysteresis in carbon black–filled butyl rubber compounds

2018 ◽  
Vol 32 (09) ◽  
pp. 1850100 ◽  
Author(s):  
M. A. Alzamil ◽  
K. Alfaramawi ◽  
S. Abboudy ◽  
L. Abulnasr
Keyword(s):  
Carbon Black ◽  
Electrical Conduction ◽  
Electrical Resistance ◽  
Conduction Mechanism ◽  
Electron Tunneling ◽  
Nonlinear Behavior ◽  
Butyl Rubber ◽  
Heating And Cooling ◽  
Rubber Compounds ◽  
Heating Effects

Temperature and concentration dependence of electrical resistance of butyl rubber filled with GPF carbon black was carried out. Current–voltage (I–V) characteristics at room-temperature were also investigated. The I–V characteristics show that the behavior is linear at small voltages up to approximately 0.15 V and currents up to 0.05 mA indicating that the conduction mechanism was probably due to electron tunneling from the end of conductive path to the other one under the action of the applied electric field. At higher voltages, a nonlinear behavior was noticed. The nonlinearity was attributed to the joule heating effects. Electrical resistance of the butyl/GPF composites was measured as a function of temperature during heating and cooling cycles from 300 K and upward to a specific temperature. When the specimens were heated up, the resistance was observed to increase continuously with the rise of temperature. However, when the samples were cooled down, the resistance was observed to decrease following a different path. The presence of conduction hysteresis behavior in the resistance–temperature curves during the heating and cooling cycles was then verified. The electrical conduction of the composite system is supposed to follow an activation conduction mechanism. Activation energy was calculated at different filler concentrations for both the heating and cooling processes.

scholarly journals Impact of a nanomixture of carbon black and clay on the mechanical properties of a series of irradiated natural rubber/butyl rubber blend

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 662-670
Author(s):  
Dalal M. Alshangiti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Theoretical Models ◽  
Butyl Rubber ◽  
Clay Nanoparticles ◽  
Vinyl Silane ◽  
Link Density ◽  
Cross Link Density

Abstract A series of natural rubber/butyl rubber NR/IIR blend loaded with N660 carbon black (CB) and triethoxy vinyl silane treated clay nanoparticles (TCNPs) were prepared using gamma irradiation in the presence of a polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). The effect of incorporating different contents of N660 CB and five parts per hundred of rubber (phr) of treated clay on the mechanical properties of the prepared nanocomposites has been investigated. The addition of TCNP to CB/rubber composites markedly increase their tensile strength due to the increase of the cross-link density. These results indicated that the TCNP may be enclosed or trapped in the occluded structure of CB. The effect of CB and the TCNP content on the tensile strength (σ), elongation at break (ε b, %), and modulus of elasticity (E, MPa) of natural rubber/butyl rubber NR/IIR blend have been investigated. The incorporation of 5 phr of TCNP into 30 phr CB-loaded NR/IIR composites results in the increased tensile strength value by about 60%. Finally, theoretical models were used to interpret the experimental results.

Electrically Conducting Rubber

1949 ◽  
Vol 22 (2) ◽  
pp. 535-554
Author(s):  
K. A. Lane ◽  
E. R. Gardner
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Carbon Black ◽  
Advanced Degree ◽  
Static Electricity ◽  
Electrically Conducting ◽  
Rubber Compounds ◽  
Electrical Resistivities ◽  
Conveyor Belts ◽  
Conducting Rubber

Abstract In recent years the dangers and inconveniences arising from the presence of static electrical charges on rubber conveyor belts, rubber flooring, rubber-tired vehicles and the like, have aroused interest in the use of electrically conducting rubber as a means of minimizing the accumulation of static electricity. Conventional rubber compounds, which have electrical resistivities normally above 107 ohm-cm, and as high as 1014–1016 ohm-cm. for nonblack compositions, favor the accumulation of static charges. By using high loadings of channel black, the resistivity can be reduced considerably. If special types of carbon black are employed the resistivity can be reduced to a very low value ; in fact, the development of a compound with a resistivity of 1 ohm-cm. has been reported. A compound with a resistivity of about 10 ohm-cm., processible on ordinary factory-size rubber machinery, is described later in this paper. Rubber compounds with resistivities less than 107 ohm-cm. are generally grouped under the generic title of “electrically conducting rubbers”. The conduction of electricity through rubber-carbon black compositions is attributed to the ability of the carbon black to form chains of particles through the rubber. The formation of these chains depends on the particle size, crystal structure, and degree of dispersion of the black. The special types of black referred to above, termed conducting blacks, possess this ability for chain formation to an advanced degree. The work described below deals with the compounding of conducting rubbers, their application, and the methods used for testing. It appears under three main headings: measurement of resistivity; development of highly conducting rubber ; and development and testing of antistatic tires.

Dynamic-Mechanical Characteristics of Rubber Compounds

1956 ◽  
Vol 29 (4) ◽  
pp. 1215-1232 ◽  
Author(s):  
S. de Mey ◽  
G. J. van Amerongen
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Loss Factor ◽  
Mechanical Characteristics ◽  
Strain Curve ◽  
Shear Loading ◽  
Butyl Rubber ◽  
Amplitude Dependence ◽  
Dynamic Mechanical ◽  
Rubber Compounds

Abstract Since rubber articles are often exposed in service to small periodic deformations, great interest attaches to the dynamic-mechanical characteristics of rubber. It has been established that the conditions under which these characteristics are determined have a pronounced influence on the results obtained, so that the measurements must be undertaken under precisely specified conditions. A new test apparatus is described for measuring the dynamic-mechanical characteristics, with which measurements can be performed at any desired stress setting, frequency, temperature, and amplitude on the same samples, both for compression and for shear loading. The incompressibility of filler-free natural-rubber compounds has been demonstrated by measurements made on samples with different shape factors and with varied static initial stress, under compression and with shear loading. The temperature, frequency, and amplitude dependence of the dynamic-mechanical characteristics of different rubber compounds is discussed on the basis of a number of measurements. The maximum value of the loss factor, which occurs in the vicinity of the second-order transition point, appears at a higher temperature in GR-S (cold rubber), Vulkollan, and Butyl rubber than in natural rubber. There is a connection between this fact and the much greater frequency and temperature dependence of Butyl rubber compared to natural rubber in the vicinity of room temperature. A compound based on natural rubber and a styrene-butadiene (85/15) co-polymer shows two maxima in the loss factor. One of these is characteristic of natural rubber, the other of the polymer. The dynamic characteristics of filler-free rubber compounds are not very sensitive to amplitude. It is found that the marked amplitude dependence of reinforced rubber compounds cannot be accounted for by increased temperature or by any nonlinearity of the stress-strain curve. The influence of composition on the dynamic-mechanical characteristics of natural rubber has been tested for a number of compounds. It is established that the carbon black types can have a significant effect on the E′ modulus. At small amplitudes the magnitude is greater for a compound containing SAF or EPC carbon black than for one containing HAF carbon black. Natural rubber reinforced with Aerosil or aniline resin shows a small loss factor, while compounds vulcanized with Thiuram show a large one. The present study is part of a fundamental investigation on rubber carried out by the Research Division of the Rubber-Stichting in Delft under the direction of H. C. J. de Decker.

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.

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