Carbon black is widely used as an active filler in the rubber industry to improve the physical properties of rubber. The surface
energy of carbon black is high compared to that of various elastomers like styrene–butadiene rubber (SBR), butadiene rubber
(BR) and ethylene–propylene–diene rubber (EPDM). The work aims at reducing the surface energy of carbon black by modifying
its surface for application especially in rubber blends. The present paper looks into the possibility of using plasma polymerisation
of acetylene as a surface modification technique for carbon black in comparison with silica. Thermogravimetric analysis, wetting
behaviour with various liquids of known surface tension and time of flight secondary ion mass spectrometry (ToF-SIMS) were
used to characterise the carbon black before and after surface modification. The study shows that surface modification of
carbon black by plasma polymerisation is difficult in comparison with silica, unless treated for long duration. The mechanistic
aspects of the surface modification and the importance of active sites on the carbon black surface for effective modification
are discussed in the paper. 相似文献
Ball-milling of N660 carbon black and graphite causes a deep activation of its surface activity which can be measured by a significant increase in the bound rubber level and in the amount of grafted rubber in comparison to the pristine untreated samples. The bound rubber measurement has been done also on a natural rubber masterbatch filled with extracted fullerene carbon black (EFCB). Also in this case extremely high levels of rubber grafting have been achieved in comparison to pure untreated graphite. It is discussed and demonstrated that the fullerene-like nanostructures in carbon blacks play a key role in the formation of bound rubber phenomenon and in grafting natural rubber on carbon black surface. 相似文献
Positron lifetime spectra and Doppler broadening of the annihilation line were measured for samples of carbon black/polyethylene and polypropylene composites with varying amount of the filler. Tensile strength, resistivity, EPR resonance were studied in addition to have the samples better characterized. The decrease in resistivity of samples, accompanied by the worsening of mechanical properties, the drop both in the intensities of Ps lifetime components in the lifetime spectra and in the line-shape parameter values, were observed with increase in the carbon black content. The presence of radicals associated with aromatic structure of the carbon sheets and others associated with the surface oxygen functional groups was established by EPR measurements for the carbon blacks being used as fillers. The carbon black of the highest specific surface area influenced the measured characteristics the most. 相似文献
Rubber compounds are reinforced with fillers such as carbon black and silica. In general, filled rubber compounds shows smooth rheological behavior and mechanical properties. Variation in rheological behavior and mechanical properties was studied in terms of the filler composition using natural rubber compounds filled with both carbon black and silica CB/Si = 0/60, 20/40, 30/30, 40/20 and 60/0 phr (parts per hundred rubber is parts of any non-rubbery material per hundred parts of raw gum elastomer (rubbery material)). The rheological behaviour can be showed in measurement of Mooney viscosity and cure time. The Mooney viscosity of rubber compounds increase with the increasing the carbon black in the compounds. The compound filled with CB/Si of 30/30 and 60/0 showed abnormal rheological behaviour in which the cure time decreased suddenly and the increased at certain ratio during the measurement. The mechanical properties such as hardness, abrasion resistance and tensile stress at 300% elongation were studied. In the hardness and abrasion resistance measurement, the higher ratio CB/Si decrease contribution of silica, which resulting smaller of hardness value. Ratio CB/Si 40/20 gives an optimum filler blended. It is also clearly understood that higher abrasion resistance mainly due to the lower hardness value under the same condition. The tensile stress at 300% elongation of rubber compound increased with the increasing carbon black filler. 相似文献
Effects of carbon filler on the sorption and diffusion of carbon dioxide in natural rubber and in styrene-butadiene rubber have been studied. Sorption isotherms conform to Henry's law in unfilled rubber and to Langmuir's law in carbon black. The isotherms in filled rubber exhibit a combination of the two sorption modes. The Henry's law solubility parameter kD increases with carbon filler content; the Langmuir saturation constant C′A initially is constant with filler level, but then decreases abruptly when carbon particles begin to aggregate. The diffusion coefficient decreases with increasing filler content, presumably owing to geometric effects and to polymer chain immobilization in the interfacial regions. 相似文献
The effect of Alkanolamide (ALK) loading on properties on three different types of carbon black (CB)-filled rubbers (SMR-L, ENR-25, and SBR) was investigated. The ALK loadings were 1.0, 3.0, 5.0 and 7.0 phr. It was found that ALK gave cure enhancement, better filler dispersion and greater rubber–filler interaction. ALK also enhanced modulus, hardness, resilience and tensile strength, especially up to 5.0 phr of loading in SMR-L and SBR compounds, and at 1.0 phr in ENR-25 compound. Scanning electron microscopy (SEM) proved that each optimum ALK loading exhibited the greatest matrix tearing line and surface roughness due to better rubber - filler interaction. 相似文献
Recently, carbon nanofibers have become an innovative reinforcing filler that has drawn increased attention from researchers. In this work, the reinforcement of acrylonitrile butadiene rubber (NBR) with carbon nanofibers (CNFs) was studied to determine the potential of carbon nanofibers as reinforcing filler in rubber technology. Furthermore, the performance of NBR compounds filled with carbon nanofibers was compared with the composites containing carbon black characterized by spherical particle type. Filler dispersion in elastomer matrix plays an essential role in polymer reinforcement, so we also analyzed the influence of dispersing agents on the performance of NBR composites. We applied several types of dispersing agents: anionic, cationic, nonionic, and ionic liquids. The fillers were characterized by dibutylphtalate absorption analysis, aggregate size, and rheological properties of filler suspensions. The vulcanization kinetics of rubber compounds, crosslink density, mechanical properties, hysteresis, and conductive properties of vulcanizates were also investigated. Moreover, scanning electron microscopy images were used to determine the filler dispersion in the elastomer matrix. The incorporation of the carbon nanofibers has a superior influence on the tensile strength of NBR compared with the samples containing carbon black. It was observed that addition of studied dispersing agents affected the performance of NBR/CNF and NBR/carbon black materials. Especially, the application of nonylphenyl poly(ethylene glycol) ether and 1‐butyl‐3‐methylimidazolium tetrafluoroborate contributed to enhanced mechanical properties and electrical conductivity of NBR/CNF composites. 相似文献
Specific features of the structure of a rigid framework composed of aggregated carbon black particles in rubber were considered. The volume fractions of the main components of the material—the filler, the binder, the layer enveloping carbon black particles, and the polymer entrapped by aggregates—were calculated. It was found that the volume fraction of the polymer in the layer around filler particles can be very high. The average number of contacts between neighboring aggregates in rubber with a high filler content is six. During deformation, the structure undergoes strong changes, so that neighboring aggregates can move from each other or, conversely, the remote aggregates can approach each other. 相似文献
This paper is concerned with the development of a hydrodynamic model for the reinforcement of rubber by colloidal fillers such as silica and carbon black. Each fractal aggregate is replaced by an equivalent effective sphere, and the reinforcing ability of the latter is estimated using the Christensen‐Lo solution of the “three‐phase composite sphere model”. With a single adjustable parameter, the model allows a quantitative interpretation of the small‐strain modulus of rubber loaded with up to 50 PHR of N234 carbon black, which falls just below the filler overlap concentration. No additional contributions to the small‐strain modulus by filler–filler “interactions” are needed to interpret the data.
A branched filler aggregate made up of spherical primary particles (black) and the effective sphere replacing it (gray). 相似文献
Rubber articles derive most of their mechanical properties from the admixture of reinforcing fillers. Most commonly, carbon black is used as reinforcing filler. If silica is used instead, tyres made with such rubber compounds may exhibit a rolling resistance reduction by ca. 30%, which translates in substantial fuel savings of a car. Such silicas are far more difficult to mix with rubber than carbon black. Coupling agents are used as a surface modification of the filler to enhance compatibility with the polymer. Additionally they improve the ease of mixing with the rubber. The development of proper coupling agents combined with improved mixing techniques has contributed to the final break-through of the silicareinforced “Green Tyre”. 相似文献
Penetration and permeation of water into polyethylene based polymers filled with carbon blacks was studied as a function of composition using radiochemical and gravimetric methods. The water absorption capacity of the filled polymers depends mainly on the oxygen content of the carbon black particles and the rate of penetration is inversely proportional to the filler loading. A mechanism of water diffusion consistent with permeation experiments is proposed. 相似文献
The performance of reinforced rubber compounds depends on the filler composition while the reinforcement and dissipation mechanisms still remain unclear.Herein linear and nonlinear dynamic rheological responses of carbon black/silica hybrid filler filling nature rubber compounds are investigated.The rheological contributions of dynamically retarded bulk phase and filler network are revealed to be crucial at high and low frequencies,respectively,and the bulk phase is shown to be of vital importance for the occurrence of nonlinear Payne effect at mediate frequencies.A framework for simultaneously solving reinforcement and dissipation varying with filler composition and content is suggested,providing a new perspective in understanding the filling effect for manufacturing high-performance rubber materials. 相似文献
The aim of this paper is to demonstrate that the stress–strain behavior of natural rubber reinforced with short pineapple leaf fiber (PALF) can easily be manipulated by changing the cross-link density and the amount of carbon black (CB) primary filler. This gives more manageable control of mechanical properties than is possible with conventional particulate fillers alone. This type of hybrid rubber composite displays a very sharp rise in stress at very low strains, and then the stress levels off at medium strains before turning up again at the highest strains. The composites studied here contain a fixed amount of PALF at 10 part (by weight) per hundred rubber (phr) and varying carbon black contents from 0 to 30 phr. To change the cross-link density, the amount of sulfur was varied from 2 to 4 phr. Swelling ratio results indicate that composites prepared with greater amounts of sulfur and carbon black have greater cross-link densities. Consequently, this affects the stress–strain behavior of the composites. The greater the cross-link density, the less is the strain at which the stress upturn occurs. Variations in the rate of stress increase (although not the stress itself) in the very low strain region, while dependent on fillers, are not dependent on the crosslink density. The effect of changes in crosslinking is most obvious in the high strain region. Here, the rate of stress increase becomes larger with increasing cross-link density. Hence, we demonstrate that the use of PALF filler, along with the usual carbon primary filler, provides a convenient method for the manipulation of the stress–strain relationships of the reinforced rubber. Such composites can be prepared with a controllable, wide range of mechanical behavior for specific high performance engineering applications. 相似文献
Natural rubber obtained from a milky colloid (latex) extras mainly from the tree Hevea Brasiliensis is approximately 95% cis-polyisopren has important physical properties. Among its shortcomings are resistance to aging and thermal stability that limits its applications. The use of fillers in rubber is almost as old as the use of rubber itself. ZnO originally used for whiteness was the first “active” filler. In 1904 carbon black was discovered and since then became the most important powder used in rubber technology. Recently various mineral and organic nanoparticles are studied as reinforcements for elastomers in view -with minimum amounts – to achieve required properties. Natural rubber nanocomposites bring together mechanical and thermal properties from the rubber matrix and special characteristics of the nanoparticles. 相似文献