Carbon Black Loading Research Articles

Effect of carbon black loading on mechanical, conductivity and ageing properties of Natural Rubber composites

Abstract Rubber is one of the important materials generally used to produce electrical rubber matting, insulators, gasket and pipe sealing rings due to good mechanical strength, conductivity and reasonable service life with addition of other compounding ingredients including fillers. Carbon black is the reinforcing fillers which added in NR composites to improve the mechanical properties and conductivity. The main objective of this study is to investigate the effect of different types of carbon black (N220, N330, N550, N660 and N774) and filler loading (0, 10, 20, 30, 40 and 50 phr) on mechanical, conductivity and ageing properties of natural rubber composites. The compounding was carried out using laboratory-sized two-roll mills. Tensile test were performed according to ASTM D 412 and tear test were performed according to ASTM D 624 by using Instron machine 3366. Electrical resistivity was studied by using Advantest R8340. Accelerated aging test was performed according to ASTM D 572 at 100°C for 3 and 6 days followed by tensile and resistivity test. It was found that N220 gives better mechanical and conductivity properties compared to other types of carbon black. Results also indicated that the optimum tensile strength was attained at 20 phr of carbon black filler loading. For tear resistance, the values were increased with increasing filler loading and for resistivity properties; the threshold was observed at 20 phr. The ageing behaviour for 3 days and 6 days at 100°C showed the optimum tensile strength obtained at 30 phr of carbon black loading. On the other hand, the resistivity properties were similar before and after ageing. Overall, the types of carbon black has significantly influenced in the mechanical properties and the resistivity threshold of NR composites.

Effect of carbonized wood fiber and carbon black loading on density, tensile properties, electrical conductivity and swelling of ethylene vinyl acetate copolymer composites

Abstract Challenges faced to develop conducting polymer composites (CPCs) comprised of poor electro-active stability, control of the mobility, mechanical properties, presentation and concentration of bioactive molecules. Carbonized wood fiber (CWF) with diameter size of 110 µm was successfully produced from waste wood fiber grade B by using conventional furnace machine at 700°C in air atmosphere for 3 hours. In this study, the effect of CWF and carbon black (CB) on the properties of ethylene vinyl acetate (EVA) composites was studied. The samples were prepared by using brabender plasticoder at temperature 160°C with rotor speed of 50 rpm. The result indicated that EVA/CB composites showed higher density, void content, tensile strength, and electrical conductivity but lower elongation at break and swelling compared to EVA/CWF composites. Both composites showed increment in density, void content, and electrical conductivity, and reduced tensile strength, elongation at break, and swelling with increasing of filler loading in EVA composites.

Thermoplastic polyurethane-carbon black nanocomposite coating: Fabrication and solid particle erosion resistance

Carbon black (CB)/thermoplastic polyurethane (TPU) nanocomposites with a range of nanoparticle loadings were prepared successfully by using a joint co-coagulation technique and hot pressing. The presence of hydrogen bonding interactions between the CB particles and TPU chains was identified from the results of Fourier transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC). Uniform dispersion of CB particles throughout the TPU matrix improved the overall mechanical properties of the TPU nanocomposites, as compared with the neat TPU. The thermal conductivity and thermal stability of the CB/TPU nanocomposites were also found to be enhanced with increasing the CB loading. All samples exhibited a rapid increase of erosion rate with the impact velocity between 20 and 30 m/s. The largest and smallest erosion rates (ER) were observed at 30° and 90° impact angle, respectively, for all CB/TPU nanocomposites. This shows a typical ductile erosion behavior in this material. In addition, the ER (TPU-2CB > TPU-12CB > TPU > TPU-6CB) under all test conditions showed an opposite trend to the tensile strength. These results indicate that the CB/TPU nanocomposites are suitable for protective coatings.

Comparison of Electrospun Carbon−Carbon Composite and Commercial Felt for Their Activity and Electrolyte Utilization in Vanadium Redox Flow Batteries

AbstractA low cost highly active carbon−carbon composite fiber felt was produced by electrospinning a mixture of polyacrylonitrile and carbon black powder using poly acrylic acid as a binder for high carbon black loading. The newly designed high‐surface area electrode material showed promising results for use as electrode material for both the negative and positive half‐cell of vanadium redox flow batteries. Battery test results demonstrated promising performance for the electrospun carbon fibers at current densities below 60 mA cm−2, but were less active at higher values. The microstructure of the felt was characterized by X‐ray computed tomography to obtain the porous pathways, which facilitate electrolyte transport. The obtained results will help us to understand the role of porosity in the performance of the battery and to consequently improve the design of the carbon‐filled electrospun material.

High porous carbon black based flexible nanocomposite as efficient absorber for X-band applications

The light weight and flexible nanocomposites comprising of high porous carbon black (CB) nanoparticles dispersed in the matrix of low density polyethylene (LDPE) are reported in this work as an efficient microwave absorbing materials for the X-band applications. The synthesized nanocomposites are characterized in terms of the x-ray diffraction and scanning electron microscopy analyses in order to understand the electromagnetic absorption process at micro level. The microwave scattering coefficients of the synthesized dielectric nanocomposites with various activated CB loadings are measured using the vector network analyzer, which are then used to extract the complex permittivity (ε) of these samples. The enhancement in the loss tangent factor with an increase in the activated CB loadings may be attributed to the elevated interfacial polarization at the activated CB - LDPE interface. The transmission line theory with metal backed condition is used to estimate the reflection losses in the synthesized nanocomposites. The minimum reflection loss of −17.54 dB at 10.05 GHz (maximum absorption of 98.24%) is achieved for 50 wt% activated CB/LDPE sample, while 10 wt% activated CB/LDPE sample offers the reflection loss of –9.24 dB at 10.22 GHz (maximum absorption of 88.08%) for common thicknesses of 2.4 mm. The synthesized nanocomposites (specific density ∼1.28 g/cc) with 50 wt% activated CB loading offers an outstanding absorption level in the X-band of microwave frequency and therefore can be used as light weight and flexible microwave absorber for X-band applications.

Thermoplastic vulcanizates based on waste truck tire rubber and copolyester blends reinforced with carbon black

Devulcanized rubber (DR) was prepared from waste truck tire rubber via thermo-chemical devulcanization process. Thermoplastic vulcanizates (TPVs) based on blending of DR and copolyester (DR/COPE) were prepared. Effects of carbon black loading on microstructure, mechanical properties and elastomeric behaviors of dynamically cured DR/COPE blends were investigated. It was found that increasing of the carbon black loadings leads to transformation from co-continuous phase structure to dispersion of smaller vulcanized rubber domains in the COPE matrix. Furthermore, the carbon black was well dispersed in the DR/COPE matrix up to 10 wt% and then the aggregates slightly occurred with increasing of carbon black loadings. In addition, dynamic experiments proved that a progressive non-linear behavior was more pronounced with increasing of carbon black loadings. Also, tan δmax of the DR phase decreases with increasing carbon black concentration indicating mainly localization of filler in rubber phase. Moreover, it was found that increases of CB loadings resulted in increase of tensile strength and hardness while the elongation at break was slightly decreased. Additionally, the rate of stress relaxations was found to be increased with increasing CB loadings.

Optical and dielectric dispersion parameters of general purpose furnace (GPF) carbon black reinforced butyl rubber

Optical and dielectric dispersion parameters for butyl rubber–general purpose furnace carbon black (IIR-GPF CB) composites with various carbon black (CB) concentrations were determined using ultraviolet transmittance spectra. X-ray diffraction (XRD) for the composite samples was measured in the 2θ range from 5° to 50°. There was a slight increase in the XRD peak intensity by increasing CB content indicating some significant changes in the composite structure. Some structural parameters were calculated for the XRD fundamental peak. The crystallite size increased significantly with the increase in carbon black concentration. This suggested a tendency of the polymer toward a more crystal state. Analysis of refractive index dispersion was carried out using Wemple–DiDomenico single effective oscillator model. The energy of effective single oscillator ( $$E_{\text{o}}$$ ) and the dispersion energy ( $$E_{\text{d}}$$ ) were estimated for the composites of different CB loadings. Accordingly, the moments of optical spectra, static and high-frequency dielectric constants were calculated. The variation of the real part $$\varepsilon_{1}$$ and imaginary part $$\varepsilon_{2}$$ of the complex dielectric function with the incident photon wavelength was investigated. The recorded values of $$\varepsilon_{1}$$ were greater than the values of $$\varepsilon_{2}$$ . The dielectric energy loss was specified by means of three important parameters: volume energy loss function, surface energy loss function and dielectric loss factor ( $$\tan \delta$$ ). The dielectric relaxation time $$\tau$$ and plasma frequency were studied as a function of incident photon wavelength for different composite samples. There was a great dependence of $$\tau$$ on the wavelength and amount of the carbon black in the composite.

Electrical and Tensile Properties of Carbon Black Reinforced Polyvinyl Chloride Conductive Composites

Conductive polymer composites are becoming more important and useful in many electrical applications. This paper reports on the carbon black (CB) reinforced polyvinyl chloride (PVC) conductive composites. Conductive filler CB was reinforced with thermoplastic PVC by compression molding technique to make conductive composites. The particle size of CB was measured, as it affects the electrical conductivity of the composites. Different types of CB-PVC compression-molded composites were prepared, using CB contents from 5 to 30 wt %. The electrical and tensile properties of these composites were studied and compared. Improved electrical properties were obtained for all CB-PVC conductive polymer composites compared to virgin PVC composite. However, the tensile properties of the CB-PVC composites increased up to 15 wt % CB loading, and then decreased, and elongation at break decreased with increasing CB loading. The structure of the CB, PVC and CB-PVC composites were studied by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic analysis. ATR-FTIR spectra provide evidence of the formation of CB-PVC composites. The microstructural analyses showed a good dispersion of CB in PVC matrix.

The effect of carbon black (CB) loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber (Nbrv)/recycled acrylonitrile butadiene rubber (Nbrr) blends

Recently, the interest of polymer industry researchers have grown rapidly on the use of specific techniques which can reduce cost and utilize rubber waste into the processing form. The increasing of cognizance in environmental matters and the desire to sustain the resources had fortified the practice of recycling waste materials. In this work, the effect of carbon black loading on curing characteristics and mechanical properties of virgin acrylonitrile butadiene rubber/recycled acrylonitrile butadiene rubber (NBRv/NBRr) blends were studied. Cure time (t90), scorch time (tS2) and swelling percentage decreased but minimum torque (ML) and maximum torque (MH) increased with increasing carbon black (CB) loading in the blends. Increasing CB loading also increased tensile strength, tensile modulus (M100), hardness and compression set but decreased elongation at break (Eb) of NBRv/NBRr blends.

Determination of vulcanization rate constant, crosslink density, and free sulfur content on carbon black flled EPDM

Different ethylene propylene diene monomer (EPDM) composite with the carbon black (CB) variation of 50, 60, and 70 phr (per hundred rubbers) is compounded by using an efcient (EV), semi-efcient (SEV), and conventional (CV) sulfur vulcanization systems. This research aims to investigate the effect of vulcanization systems and carbon black content on the vulcanization rate constant, the crosslink density, and the free sulfur content. This research shows the EV system resulting in the fastest vulcanization rate constant (0.0191/second), the lowest overall crosslink density (0.0022 mol.cm -3 ), and the highest percentage of free sulfur content in the EPDM vulcanization (0.40 %). The CV system provides the slowest vulcanization rate constant (0.0061/second) and the highest overall crosslink density (0.0034 mol/cm -3 ). The percentage of free sulfur content in the EPDM vulcanization of CV system is between EV and SEV systems. The SEV system provides the vulcanization with the characteristic of vulcanization rate constant and overall crosslink density between EV and CV systems as well as provides the lowest percentage of free sulfur content (0.29 %). The higher carbon black loading in each vulcanization systems means the lower rate constant of vulcanization and the higher overall crosslink density.

Effect of polyamide 6 on the morphology and electrical conductivity of carbon black-filled polypropylene composites.

Carbon black (CB)-filled polypropylene (PP) with surface resistivity between 106 and 109 Ω sq−1 is the ideal antistatic plastic material in the electronics and electric industry. However, a large amount of CB may have an adverse effect on the mechanical properties and processing performance of the material, thus an improved ternary system is developed. Blends of CB-filled PP and polyamide 6 (PA6) have been prepared by melt blending in order to obtain electrically conductive polymer composites with a low electrical percolation threshold based on the concept of double percolation. The morphological developments of these composites were studied by scanning electron microscopy. The results showed that CB particles were selectively dispersed in PA6 phases due to the good interaction and interfacial adhesion between CB and PA6. At the same CB loadings, the surface resistivity of PP/PA6/CB composite was smaller than that of PP/CB composite system, which indicated the better conductivity in the former composite. The increasing amount of PA6 in the composites changed the morphology from a typical sea–island morphology to a co-continuous morphology. What is more, with 8 wt% of CB and PP/PA6 phase ratio of 70/30 in which the PP and PA6 phases formed a co-continuous structure, the electrical conductivity of the composite peaked at 2.01 × 105 Ω sq−1.

Non―Gaussian-Type Tube-Based Entropy Model for Elastomeric Networks with Polymer Phase Influenced by Filler Loading: Data Analysis for Lightly to Highly Carbon-Black Filled Styrene-Butadiene Rubber Networks

ABSTRACTRecently the author proposed a new, non-Gaussian, tube-based entropy model for filled elastic networks, characterized by a filler-environmental parameter that was proposed to represent the extent of filler-agglomeration; it was specifically introduced for the polymer phase entropically affected by the presence of very irregularly structured fillers. In this report, the stress-strain relations derived from the above model were used together with the traditional and latest mechanisms of amplification of the strain due to the presence of a filler: namely, literature tensile data for styrene-butadiene rubber networks with a series of carbon-black loadings were systematically analyzed to understand the filler-loading dependence of the above parameter. As a consequence, it is proposed that this parameter is linked, from the static-mechanical standpoint, to a critical filler-loading coupled to the filler-networking. In addition, prior to commencing the examinations of the high-loading networks' tensile data, the data-fitting performance of the underlying elastic molecular model for non-filled networks was also examined using the unfilled and low-loading networks' tensile curves.

Reinforcement Mechanism of Carbon Black (CB) in Natural Rubber Vulcanizates: Relationship Between CB Aggregate and Network Structure and Viscoelastic Properties

ABSTRACTCarbon black (CB) aggregates in CB-filled natural rubber (NR) vulcanizate were joined together and formed CB aggregates in the CB region less than 20 phr. It was found that the viscoelastic behavior was related to the hydrodynamic interaction between CB aggregate and NR matrix. In the CB loading region more than 40 phr, CB aggregates formed CB network structure in it. Using the parallel mechanical model of the two phases of a rubber matrix and an immobilized CB/NR interfacial layer excluding a CB phase, it was possible to quantitatively explain the relationship between the viscoelastic behavior of CB network structure.

Improving the Efficiency of Carbon Cloth for the Electrogeneration of H2O2: Role of Polytetrafluoroethylene and Carbon Black Loading

In this work, H2O2 is electrogenerated in the cathodic compartment of a divided filter-press cell with a carbon cloth in the configuration of a gas diffusion electrode using air as the oxygen source. The effect of Teflon content was studied, and it was found that the appropriate content is within the range 10–20%. The production was greatly enhanced after the air-brushing deposition (and subsequent annealing) of simply 0.5 mg cm–2 of carbon black. Higher additions clogged the pores and as a result were counterproductive in terms of H2O2 generation. At a current density of 25 mA cm–2, the production rate was 15 mg of H2O2 h–1 cm–2 with a current efficiency close to 100%. Production rate increased with current density up to more than 40 mg of H2O2 h–1 cm–2 at 87.5 mA cm–2. The good performance and ease of preparation of this electrode make it an interesting alternative to generate hydrogen peroxide for electro-Fenton processes.

Enhanced tortuosity for electrolytes in microwave irradiated self-organized carbon-doped Ni/Co hydroxide nanocomposite electrodes with higher Ni/Co atomic ratio and rate capability for an asymmetric supercapacitor

We demonstrate a green, facile and rapid microwave-mediated process for fabricating carbon black (CB) incorporated Ni/Co hydroxide porous nanocomposites and study the effect of various mass loading of CB on supercapacitor performance. The structure and interactions between CB and Ni/Co hydroxide are characterized by using x-ray diffraction, Fourier-transform infrared spectroscopy and x-ray photoelectron spectroscopy, which suggest the miniaturization of the single-phase Ni/Co hydroxide formation time. A morphology study reveals that the addition of CB into Ni/Co hydroxide develops a loose network structure with well-defined architectural pores. In addition, the nanocomposites demonstrate noticeable improvements in porosity and atomic ratio of Ni/Co with an increasing percentage of carbon, which results in a higher diffusion of electrolytes, and hence electrical conduction. The developed electrode materials exhibit a maximum specific capacitance value of 1526 Fg−1 at current density 1 Ag−1 with excellent cyclic stability (92% retention at 5000 cycles), energy density (76 Wh Kg−1), power density (250 W Kg−1) and rate capability. A solid state asymmetric supercapacitor device is fabricated and utilized to brighten a commercial LED effectively for validating real usage.

Fabrication of shape memory natural rubber using palmitic acid

This paper investigates the practicability of fabricating a shape memory natural rubber with the use of palmitic acid as the swelling agent. Strips of natural rubber samples were swollen in molten palmitic acid at 75°C. Equilibrium swelling of natural rubber with palmitic acid was found to occur at approximately 50min of swelling time. Under cooling effect, the palmitic acid crystallized to form a percolated crystalline platelet network. These networks allow fabricated shape memory natural rubber (SMNR) to deform and recover its shape at a temperature above the melting point of palmitic acid. Under controlled uniaxial stress, the natural rubber sample with 0 parts per hundred rubber (phr) carbon black loading exhibits fixity and recovery of 80±10%. Motivation of this research is primarily on practicability of palmitic acid to be used as a swelling agent for shape memory properties. Results show that palmitic acid is a relatively good swelling agent to induce shape memory properties into natural rubber.

Effect of thermal-air ageing treatment on mechanical properties and electromagnetic interference shielding effectiveness of low-cost nano-structured carbon filled chlorinated polyethylene

Easy fabrication of flexible and high-performance polymeric composites for radiation shielding has been prioritized since the last few decades. But most of the materials have been suffering from lack of durability in environmental exposures. Herein, to develop a new flexible composite with significant mechanical robustness and longtime durability, a low percolating nano carbon clusters reinforced polymer composite has been proposed. The chlorinated polyethylene (CPE) composite showed low percolation threshold (13.7wt%), and superior electromagnetic interference (EMI) shielding value (42.4dB) at 40wt% conductive Vulcan XC-72 (VXC) carbon black loading. It was assessed that CPE composites have excellent serviceability on desired mechanical and EMI shielding properties after thermal-air ageing treatment. Altogether, this work provides an economical way to fabricate flexible CPE composites as serviceable EMI shield material with desired attributes.

Carbon Black Loaded Composite Poly(Dimethyl Siloxane) Membrane Preparation and Application for Hazardous Chemical Removal from Water

Carbon Black Loaded Composite Poly(Dimethyl Siloxane) Membrane Preparation and Application for Hazardous Chemical Removal from Water

Compression stress relaxation in carbon black reinforced HNBR at low temperatures

Findings of a study of stress relaxation behaviour of hydrogenated nitrile butadiene rubber (HNBR) at nominal compressive strains up to 0.4 and temperatures above and below the glass transition temperature Tg are reported. Two formulations of a model HNBR with 36% acrylonitrile content and carbon black (CB) loading of 0 and 50 phr were investigated. The relaxation function of HNBR is found to be independent of strain at temperatures right above the Tg or at times longer than 10−3 s for the deformations employed. CB imparts higher long-term stiffness and also larger relaxation strength at times longer than 10−4 s to the HNBR, but it does not affect the relaxation behaviour of the rubber in the time span from 10−3 – 104 s. In addition, the relationship between the strain energy function of HNBR and temperature is demonstrated to have a complex concave-downward shape which is affected by two competing contributions of entropy elasticity and the stress relaxation.

Effect of carbon black composition with sludge palm oil on the curing characteristic and mechanical properties of natural rubber/styrene butadiene rubber compound

This study was conducted to investigate the possibility of utilizing sludge palm oil (SPO) as processing oil, with various amount of carbon black as its reinforcing filler, and its effects on the curing characteristics and mechanical properties of natural rubber/styrene butadiene rubber (NR/SBR) compound. Rubber compound with fixed 15 pphr of SPO loading, and different carbon black loading from 20 to 50 pphr, was prepared using two roll mills. The cure characteristics and mechanical tests that have been conducted are the scorch and cure time analysis, tensile strength and tear strength. Scorch time (ts5) and cure time (t90) of the compound increases with the increasing carbon black loading. The mechanical properties of NR/SBR compound viz. the tensile strength, modulus at 300% strain and tear strength were also improved by the increasing carbon black loading.