Carbon Black Content Research Articles

Effect of carbon black content and particle size on the phase evolution of aluminum oxy nitride (AlON)

In this work aluminum Oxy-nitride (γ-AlON) crystals were synthesized by Co-precipitation processing from Al(NO3)3 solution, magnesium acetate and nanosized carbon particles as the source of Al3+, Mg2+ and reducing agent, respectively. The effects of the nanosized carbon and Mg2+ content and particle size on the formation of AlON phase were investigated by means of XRD, SEM and EDS analysis. Our results indicated that AlON powder could be synthesized when the resultant precursors were calcined at 1700°C for 2h under flowing N2. Under optimal additional content of C (7.1wt%), the resultant AlON powders exhibited the primary particle size of about 2–4µm with a specific surface area of 3m2/g.

Piezoelectric and dielectric behavior of 0-3 asphalt-based composites with carbon black

Asphalt-based piezoelectric composites have great potential to serve as sensors to monitor the health of asphalt pavements due to their compatibility with asphalt pavements and appropriate response behaviors. This paper reports the preparation of asphalt-based piezoelectric composites doped with carbon black to investigate the influence of lead zirconate titanate (PZT) and carbon black contents on the dielectric, piezoelectric, and electromechanical properties of the composites. The addition of carbon black as a conductive phase facilitates the poling process, which improves the poling efficiency. The results indicate that with increasing PZT content, the dielectric constant (εr), piezoelectric strain factor (d33) and planar electromechanical coupling coefficient (Kp) of the composites increase. εr, d33, and Kp of the composites increase with the increase of carbon black content, and the composites with 0.3vol% carbon black present the maximum values of 154.89, 75.74 pC/N and 37.73%, respectively, then decrease with greater carbon black content. However, tanδ shows an opposite trend with the variation of PZT and carbon black contents. With 80vol% PZT and 0.3vol% carbon black, tanδ decreases to the minimum value of 20.80, then increases with further increases in carbon black content. The variation of the mechanical quality factor (Qm) shows little association with the contents of PZT or carbon black.

Manipulation of mechanical properties of short pineapple leaf fiber reinforced natural rubber composites through variations in cross-link density and carbon black loading

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.

Preparation of UCO Microspheres by Internal Gelation Process

UCO kernels were used for High Temperature Reactor (HTR) fuel, which can restrain kernels migration and avoid corrosion of cladding layer under the high burnup compared with UO2 or UC kernels. In this paper, UCO kernels were prepared by internal gelation process containing dissolving, broth preparation, dispersing, AWD (aging, washing and drying) and sintering procedures. The broth composition was studied based on the fabrication of UO2 kernels before. Effects of the carbon black content and sintering atmosphere on the microstructure and performance of microspheres were mainly studied. Surface morphology of dried microsphere was observed by integrated microscope. Grain size and the degree of densification of UCO microspheres were observed by SEM.

Electromagnetic wave absorption properties of honeycomb structured plasterboards in S and C bands

This paper provides a feasible way to design honeycomb structured plasterboard for electromagnetic (EM) wave absorption in S and C bands by filling gypsum slurry into carbon black (CB) coated paper honeycomb. The EM wave reflectivity of the prepared plasterboard was investigated by arched testing method, and the influences of CB contents and geometrical parameters of honeycomb structure on the wave absorption were analyzed. The obtained results show that the wave absorption performance of the honeycomb structured plasterboard can be enhanced by increasing the CB content and the honeycomb height, due to the enhancement of dielectric loss capacity and multiple reflections between the honeycomb walls. Moreover, the smaller honeycomb edge length is more conductive to EM wave absorption, because of the increase of the effective permittivity of the honeycomb structured plasterboard. When the edge length and height of honeycomb are 6 mm and 9 mm, respectively, and the CB content is 0.6% in mass, the reflectivity can be less than −10dB (90% EM wave is absorbed) in the frequency range of 2.5–8GHz.

Low percolation threshold and balanced electrical and mechanical performances in polypropylene/carbon black composites with a continuous segregated structure

Abstract A novel continuous segregated structure was constructed in polypropylene (PP)/carbon black (CB) composites, to improve the electrical conductive performance and achieve a balance of the electrical conductivity and mechanical properties. Compared with traditional segregated structures reported in literature, PP matrix maintained a continuous structure instead of being separated completely by the electrical conductive fillers and CB particles formed a thorough conductive network in the continuous segregated PP/CB composites. A percolation threshold as low as 0.37 vol%, which is significantly lower than the percolation threshold of melt compounded PP/CB composites (2.75 vol%) and PP/polystyrene (PS)/CB composites (3.23 vol%) with a double percolation structure, was obtained because of the formation of the two-dimensional conductive network of CB particles. The mechanical performance tests showed that the tensile modulus, strength and elongation of break could be maintained well at CB contents around the percolation threshold. That is, with this novel continuous segregated structure, a balance of strength, toughness and electrical conductivity property can be achieved in conductive polymer composites.

Conductive carbon nanotube-reinforced polymer composites and their characterization

New electrically conductive composites reinforced by single-walled carbon nanotubes were studied in this work. The main properties of conductive composites, which were developed, such as electrical (dielectric spectroscopy and volume resistivity), mechanical (elongation at break, Young's modulus, yield strength), and rheological (melt flow index (MFI)) were evaluated. Loading single-walled carbon nanotubes into carbon black/polymer composites lowers the volume resistivity of such composites. The application of a small quantity of single-walled carbon nanotubes in carbon black/polymer composites allows reducing the carbon black content and improving the rheological and processing properties. The conductive polymer composites developed as part of this study can be processed by conventional processing methods such as injection molding or extrusion. Ternary conductive composites can be applied as materials with improved processing properties in electrical engineering.

Preparation and characterization of hybrid nanocomposites based on NBR/Nanoclay/Carbon black

Acrylonitrile butadiene rubber (NBR)/carbon black (CB)/nanoclay (NC) nanocomposites containing 5 phr NC and 12, 24, and 48 phr CB with resorcinol/hexamethylenetetramine as compatibilizer were prepared in an internal mixer. The possible interacting behavior between NC and CB was studied by transmission electron microscopy, X‐ray diffraction, cure rheometry, dynamic mechanical thermal analysis, and tensile test. The results show an increased cure rate upon incorporation of 5 phr NC to NBR especially in presence of CB. It is also observed that increasing CB content in nanocomposites leads to an extra enhancement in mechanical properties and crosslink density which can be attributed to the synergistic effect between NC and CB due to formation of physical and chemical network. POLYM. COMPOS., 38:E181–E188, 2017. © 2016 Society of Plastics Engineers

EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF MAGNETORHEOLOGICAL ELASTOMER

Magnetorheological elastomers (MREs) have much interest in engineering applications. However, the mechanical properties of MREs are still under ongoing researches. This paper presents the results from tensile test, hardness and rebound test that were carried out in order to understand the mechanical properties of MRE with the influence of carbon black content. The addition of carbon black was varied with the amount of 20 pphr, 40 pphr and 60 pphr of carbon black. The development of the MRE composites was manufactured by following the conventional rubber compounding process. The optimum cure of each MRE composite was determined by using a Rheometer 100. The mechanical properties through tensile test were obtained by using an Instron Tensile Machine, meanwhile hardness and resilience were carried out by using Wallace Dead Load Hardness and Dunlop Tripsometer, respectively. The results of tensile strength were not consistent with the addition of carbon black. In meantime, hardness value increases as the carbon black increases. The decreasing pattern of MRE resilience could be observed when the carbon black content increases.

SEM study of worn surface morphology of an indigenous ‘EPDM’ rubber

Ethylene Propylene Diene Monomer (EPDM) rubber emerges as a dominant elastomer for major engineering applications like automobiles, constructions, electric and electronic industries and many more. The major engineering properties of EPDM are its outstanding heat, ozone and weather resistance ability. The resistance to polar substances and steam is also good. EPDM rubber has a common use as seals in automobiles.In the present work friction and sliding wear behaviors of ethylene propylene diene monomer rubbers (EPDM) of different hardness have been studied against steel counterpart under dry working condition. Different hardness of EPDM have been achieved by adding different proportion (parts per hundred) of carbon black (CB) content with the main ingredients of EPDM. Tribo-testing has been carried out in a multi tribo-tester (Ducom, India). EPDM rubber of different hardness like 55 Å, 70 Å and 85 Å has been slid against EN-8 stainless steel roller of the tester. Experiments have been conducted with different rotational speeds of the wheel at a constant load of 25N for a constant duration of 900 s. The coefficient of friction (COF), mass loss and wear of EPDM rubbers have been determined from the test data. The worn surface morphology has also been studied using scanning electron microscope (SEM) and concluded accordingly.Present experimental work attempts to highlight some important tribo-characteristics of an indigenous EPDM rubber as well as to shed light on various possible areas of further research works.

Suspension plasma spraying of La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes: Influence of carbon black pore former on performance and degradation

Suspension plasma spray deposition is utilized to fabricate solid oxide fuel cell cathodes with minimal material decomposition. Adding carbon black as a pore former to the feedstock suspension results in smoother and more porous coatings, but over the range of carbon black concentrations studied, has little impact on the overall symmetrical cell performance. The cathode made with a suspension containing 25 wt% carbon has the highest deposition efficiency and a polarization resistance of 0.062 Ωcm2 at 744 °C. This cathode is tested for 500 h, and it is observed that adding an SDC interlayer between the YSZ electrolyte and the cathode(s) and/or coating the metal substrate with lanthanum chromite decrease the rate of performance degradation.

Effect of carbon black content on the microwave absorbing properties of CB/epoxy composites

To prevent serious electromagnetic interference, a single-layer and double layer wave-absorbing coating employing complex absorbents composed of carbon black with epoxy resin as matrix was prepared. The morphologies of carbon black /epoxy composites were characterized by scanning electron microscope and atomic force microscope, respectively. The carbon black particles exhibit obvious polyaromatic were characterized by X-ray diffraction. The electromagnetic parameters of carbon black were measured in the frequency range of 8–12 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss using arch method. The effects of carbon black mass ratio, thickness and double-layer on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, higher ratio and double-layer of carbon black /epoxy content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of carbon black in composites.

Rheological and electrical behavior of poly(methyl methacrylate)/carbon black composites as investigated by creep recovery in shear

The rheological and electrical behavior of poly(methyl methacrylate) (PMMA)/carbon black (CB) composites has been studied as a function of CB concentration by simultaneous electrical and rheological measurements during creep and creep-recovery experiments in the linear and nonlinear regimes. The creep compliance and recoverable compliance were strongly influenced by the CB concentration in the linear regime, especially above the percolation threshold. The creep compliance remained almost unchanged in the linear and nonlinear regimes, but the recoverable compliance was strongly influenced by the creep stress. The electrical conductivity increased under low creep deformation, but under high creep deformation, the electrical conductivity decreased rapidly at the beginning of the creep experiment. After a sufficiently long creep time under shear, the electrical conductivity again increased. The results provide a deeper insight into structural changes in conductive polymer composites induced by shear deformation.

Heterocoagulation behavior of carbon black with surface encapsulation through emulsion polymerization

ABSTRACTNanocomposite microspheres containing styrene–acrylate resin, wax, and carbon black (CB) with desired CB dispersion were prepared through heterocoagulation. The CB surface was modified using conventional anionic emulsifier and anionic dispersants with different lengths of nonionic chains and reactivities or through polymer encapsulation via emulsion polymerization to regulate the dispersion and concentration of CB in the microspheres. Experimental results showed that anionic dispersants with long nonionic chains effectively dispersed and stabilized CB particles. Polystyrene (PS) was then encapsulated on the CB surface by using a reactive dispersant and a water‐soluble initiator of polymerization. The CB particles exhibited comparable pH stability with other heterocoagulation components. Overall, encapsulation through emulsion polymerization can be used to obtain not only high CB content but also improved CB distribution in the resulting microspheres. High coagulation efficiency can also be achieved using polystyrene‐encapsulated dispersed CB because of its high affinity to emulsifiers and reactive dispersants during dispersion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43516.

Fabrication and Characterization of Closed-Cell Rubber Foams Based on Natural Rubber/Carbon Black by One-Step Foam Processing

A novel one-step compression molding was proposed and successfully employed for preparation of closed-cell foams based on natural rubber (NR)/carbon black (CB) composite. The uniqueness of this new method was that both the foam density and expansion ratio became independent of the CB content. The rheometrical findings indicated that the increase in the CB content from 0 to 20 phr yielded a 0.91 and 3.51 N m increase in the initial and the final torque, respectively. The SEM results demonstrated that the prepared foam had three different layers including the skin, transition, and core layers. Almost 14-fold enhancement of the cell density (from 8 to 117 cells/cm3) was obtained by increasing the CB content in a constant foam density. Although, curing properties, cell morphology, and mechanical properties of the foam improved by increasing the CB content, the gradual deterioration was observed for sound absorption properties.

Fabrication and characterization of Magneli phase Ti4O7 submicron rods

Ti4O7 submicron rods were successfully fabricated by heat-treating H2Ti3O7 nanowires doped with nano-sized carbon black. This novel method combines the technical superiority of hydrothermal method and carbothermal reduction. In order to investigate reaction process and the influence of the addition of carbon black and reaction temperature on the reduction process, we synthesized substoichiometric titanium oxides in different conditions. The results showed that Ti4O7 submicron rods could be prepared with carbon black content of 3.7 % wt% by heating at 1075 °C for 3 h. The Ti4O7 samples with higher specific surface area showed outstanding conductivity and optical properties. The UV–Vis spectra of Ti4O7 submicron rods showed that the absorption band covered the visible region and part of the near-infrared region. The light absorption property of Ti4O7 submicron rods is quite different with that of TiO2.

Electroactive shape memory cyanate/polybutadiene epoxy composites filled with carbon black

Electroactive shape memory composites were synthesized using polybutadiene epoxy (PBEP) and bisphenol A type cyanate ester (BACE) filled with different contents of carbon black (CB). Dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), electrical performance and electroactive shape memory behavior were systematically investigated. It is found that the volume resistivity decreased due to excellent electrical conductivity of CB, in turn resulting in good electroactive shape memory properties. The content of CB and applied voltage had significant influence on electroactive shape memory effect of developed BACE/PBEP/CB composites. Shape recovery can be observed within a few seconds with the CB content of 5 wt% and voltage of 60 V. Shape recovery time decreased with increasing content of CB and voltage. The infrared thermometer revealed that the temperature rises above the glass transition temperature faster with the increase of voltage and the decrease of resistance.

Synergistic effect of boron/nitrogen co-doping into graphene and intercalation of carbon black for Pt-BCN-Gr/CB hybrid catalyst on cell performance of polymer electrolyte membrane fuel cell

Boron and nitrogen were successfully co-doped into graphene (Gr) nanosheets to which Pt nanoparticles with ∼3.7 nm are uniformly deposited on BCN-Gr. Pt content on BCN-Gr is estimated to be 50 wt.% by TG/DTA analysis. Pt-BCN-Gr is intercalated by different amount of CB (carbon black), and it is designated as Pt-BCN-Gr/CBx (x = 0.0, 0.3, 0.4, 0.5 and 0.6). The membrane electrode assembly is fabricated with commercial Pt-C and Pt-BCN-Gr/CBx as anode and cathode catalysts, respectively. The cell performance is highly consistent with electrochemical active surface area and the best cell performance of 0.54 W/cm2 in power density is achieved for Pt-BCN-Gr/CB0.5. The results show that positive effect of B and N co-doping on cell performance becomes more significant for lower intercalated CB content. Direct comparison between Pt-BCN-Gr/CB and Pt-Gr/CB clearly exhibits that Pt-BCN-Gr/CB shows better cell performance for Pt-BCN-Gr/CB than Pt-Gr/CB at lower CB content. About 28%–157% in cell performance at 0.6 V has been enhanced by B and N co-doping compared with that of Pt-Gr/CB. The enhancement in cell performance and durability is probably attributed to the synergistic effect by B and N co-doping and intercalation by CB.

Model-free non-isothermal crystallization kinetics of poly(3-hydoxybutyrate) filled with carbon black

Non-isothermal crystallization kinetics of poly(3-hydoxybutyrate) (PHB) filled with different amounts of carbon black (CB) was investigated by differential scanning calorimetry for both, the cold and melt crystallization process. The Friedman method was applied to describe the crystallization kinetics and to determine the conversion dependent apparent activation energies. It was found that carbon black acts as a nucleating agent, reducing the apparent activation energy for the crystallization onset significantly, and thus greatly facilitating the phase transformation. Considering PHB-CB compounds with CB content ≥5%, the kinetic data can only be interpreted assuming a complex multi-step crystallization mechanism, where the exact role of CB is unclear.

Effect of carbon black nanoparticles concentration on the mechanical properties of a structural epoxy adhesive

The present work describes the influence of different carbon black nanoparticles with different concentrations on the mechanical properties of a structural epoxy adhesive cured by dielectric and thermal heating. This work was undertaken to improve the understanding of the effect of carbon black nanoparticles concentration on the stiffness (Young’s modulus), strength (yield strength) and deformation of the adhesive. Two kinds of spherical carbon black nanoparticles with different dielectric properties and sizes were used. Specimens with different amounts of carbon black were manufactured for each nanoparticle. The mechanical properties of the adhesive were measured in bulk specimens. The mechanical properties were found to vary as a function of the carbon black amount. For the dielectric cure, the strength and stiffness of the adhesive decrease as the amount of carbon black nanoparticles increases. On the other hand, the adhesive showed an increase of the deformation with an increase of the carbon black concentration. The thermal cure showed a mechanical behaviour similar as the dielectric cure, but the curing time increases substantially. A scanning electron microscopy analysis was performed to analyse the surface fracture of the adhesive. The fracture surfaces of specimens cured by dielectric and thermal heating and without nanoparticles are similar, typical of brittle adhesive. For high carbon black amount, the fracture surfaces are typical of ductile adhesive.