• Elastomers and Composites
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• v.33 no.5
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• pp.355-362
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• 1998

The purpose of this paper is to develop a rational engineering conductive carbon filled composite through understanding of the effect of conductive carbon black. Polycabonate(PC), Acrylonitrile Butadiene Styrene copolymer(ABS) and PC/ABS resin were used as matrix of the conductive polymer composites. From the experimental results, PC filled with the fiber shaped carbon black showed a possibility to be a rational engineering conductive composite.

• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.101-108
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• 2003

Polymeric positive temperature coefficient(PTC) composites have been prepared by incorporating carbon black(CB) into high density polyethylene(HDPE), polyphenylene sulfide(PPS) and polybutylene terephthalate(PBT) matrices. A PTC effect was observed in the composite, caused by the large thermal expansion due to He consecutive melting of HDPE, PPS and PBT crystallites. This theory is based upon the premise that the PTC phenomenon is due to a critical separation distance between carbon particles in the polymer matrix at the higher temperature. The influence of PTC characteristics of the PPS/CB composite can be explained by DSC result. HDPE, one of prepared composition, exhibit the higher performance PTC behavior that decreaseing of negative temperature coefficient(NTC) effect and improved reproducibility by chemically crosslinking. Also, PBT/CB and PPS/CB composites exhibit the higher PTC peack temperature than HDPE/CB PTC composite, individually $200^{\circ}C$ and $230^{\circ}C$. These PTC composite put to good use in a number of safety application, such as self$.$controlled heater, over-current protectors, auto resettable switch, high temperature proctection sensor, etc.

• Polymer(Korea)
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• v.33 no.5
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• pp.477-484
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• 2009

Suspension polymerization with hydrophobic silica as a stabilizer and AIBN as an initiator was conducted to synthesize PBMA particles and PBMA composite particles containing carbon black. Surface modification of silica particles by controlling pH revealed that 90% of them functioned as stabilizer and 10% were incorporated into PBMA particles. While stabilizer concentration had no impact on reaction kinetics and particle diameter, an increase in stabilizer concentration displayed an increase in molecular weights when it exceeded 1.67 wt%. An increase in initiator concentration and reaction temperature decreased molecular weights in close agreement with the theoretical equation. An increase in carbon black concentration from 1 to 7 wt%, relative to the monomer, showed a progressive decrease in reaction conversion. As carbon black was increased from 3 to 5 wt%, glass transition showed a $4^{\circ}C$ increase. The presence of carbon black was confirmed by TEM while its concentration was measured by TGA.

• Polymer(Korea)
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• v.30 no.6
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• pp.505-511
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• 2006

We tried to prepare polystyrene composite particles containing carbon black by suspension polymerization with water as a reaction medium. Hydrophobic silica was selected as a stabilizer and oil-soluble azobisisobutyronitrile (AIBN), as an initiator. All polymerization reactions were carried out at a fixed temperature of $75^{\circ}C$. Stabilizer concentration was varied from $0.17{\sim}3.33wt%$ compared to water, where particles with $7.96{\mu}m$ in average diameter were obtained at 1.57 wt% of stabilizer. Increase in divinylbenzene concentration, as a crosslinking agent, from $0.1{\sim}1.0 wt%$ compared to monomer exhibited a large increase in average particle diameter Incorporation of 1wt% of carbon black compared to monomer produced an increase in average diameter It is speculated that viscosity lower than that necessary to induce even dispersion of carbon black particles led to poor dispersion, and as a result, large particles. For a styrene mixture containing 3 wt% carton black compared to monomer, enhanced dispersion due to an increase in carbon black concentration reduced average particle diameters. For styrene mixtures containing 1 and 3 wt% carbon black compared to monomer, preparticles before polymerization and polymer composite particles after polymerization showed a similar tendency towards particle formation. When carbon black concentration compared to monomer was increased to 5 and 7 wt%, styrene mixtures exhibited a large increase in viscosity and thus better dispersion of carbon black particles, which led to a decrease in preparticle diameters. However, these particles experienced agglomeration in the polymerization process, and polystyrene composite particles increased in average diameter.

• Elastomers and Composites
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• v.43 no.3
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• pp.157-165
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• 2008

Suspension polymerization was carried out to synthesize poly(butyl methacrylate) (PBMA) composite particles containing carbon black. Water was selected as a reaction medium, hydrophobic silica as a stabilizer and azobisisobutyronitrile as an initiator. Concentration of stabilizer was varied from 0.67 to 2.55 weight% with respect to the water, and that of initiator was varied from 0.25 to 3.00 weight% with respect to the butyl methacrylate (BMA) monomer. All polymerization reactions were conducted at 75$^{\circ}C$. It is found that stabilizer concentration has no impact on reaction kinetics, while an increase in initiator concentration enhances polymerization reaction rate. Increase of carbon black concentration from 1 to 3 to 5 wt% into PBMA displayed progressive decrease in reaction conversion. The particle diameter of PBMA composite particles containing carbon black was found to be between 5 and 30 ${\mu}m$. Glass transition was determined to range from 23.8 to 24.7$^{\circ}C$, irrespective of variation in the concentration of stabilizer, initiator or carbon black.

• Korean Journal of Materials Research
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• v.30 no.10
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• pp.522-532
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• 2020

Conductive polymer composites with high electrical and mechanical properties are in demand for bipolar plates of phosphoric acid fuel cells (PAFC). In this study, composites based on natural graphite/fluorinated ethylene propylene (FEP) and different ratios of carbon black are mixed and hot formed into bars. The overall content of natural graphite is replaced by carbon black (0.2 wt% to 3.0 wt%). It is found that the addition of carbon black reduces electrical resistivity and density. The density of composite materials added with carbon black 3.0 wt% is 2.168 g/㎤, which is 0.017 g/㎤ less than that of non-additive composites. In-plane electrical resistivity is 7.68 μΩm and through-plane electrical resistivity is 27.66 μΩm. Compared with non-additive composites, in-plane electrical resistivity decreases by 95.7 % and through-plane decreases by 95.9 %. Also, the bending strength is about 30 % improved when carbon black is added at 2.0 wt% compared to non-additive cases. The decrease of electrical resistivity of composites is estimated to stem from the carbon black, which is a conductive material located between melted FEP and acts a path for electrons; the increasing mechanical properties are estimated to result from carbon black filling up pores in the composites.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.180-187
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• 2005

This paper is focused on the development of the flexible electrode for disc-type polymer actuators using Segmented Polyurethane(SPU). This paper consists of two parts. The one is about the mechanical property such as elastic modulus. these parameters mainly affect behaviors of polymer actuators and the other is about the electro-chemical property such as the surface resistance of the composite electrode affects the strength of electrostatic force, results in the deformation of polymer actuators. The Young's modulus was measured by UTM. As result, by increasing the modulus of a body of polymer actuators, the maximum displacement of polymer actuators are decreased. The surface resistance of the electrode was measured by 4 point probe system. Compared with the conductive silver grease, the displacement of polymer actuators using carbon black(CB) composite electrodes is comparably small but CB composite electrode should be the practical approach for the improvement of the performance of all-solid actuators, compared with another types of electrode materials.

• Carbon letters
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• v.6 no.3
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• pp.173-180
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• 2005

In this study, AR (aromatic resin) pitch was employed as the matrix-precursor for carbon/carbon composite because it exhibits much higher coke yield than coal tar pitch. As a result, a fabrication process of carbon/carbon composites can be shortened. It has been known that the pitches may cause swolling problem during the carbonization process. In order to restrain the swelling occurrence, a small quantity of carbon black was added to the AR pitch. Due to addition of carbon black the swelling was decreased largely and the perform can be infiltrated with the AR pitch. The densification efficiency of the performs was compared with various matrix-precursors. The coke yield of matrixprecursors, the morphology and the degree of graphitization of carbon matrix were analyzed.

• Macromolecular Research
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• v.12 no.1
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• pp.53-62
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• 2004

We have prepared polymer composites of low-density polyethylene (LDPE) and ionomers (Surlyn 8940) containing polar segments and metal ions by melt blending with carbon black (CB) as a conductive filler. The resistivity and positive temperature coefficient (PTC) of the ionomer/LDPE/CB composites were investigated with respect to the CB content. The ionomer content has an effect on the resistivity and percolation threshold of the polymer composites; the percolation curve exhibits a plateau at low CB content. The PTC intensity of the crosslinked ionomer/LDPE/CB composite decreased slightly at low ionomer content, and increased significantly above a critical concentration of the ionomer. Irradiation-induced crosslinking could increase the PTC intensity and decrease the NTC effect of the polymer composites. The minimum switching current (Ι$\sub$trip/) of the polymer composites decreased with temperature; the ratio of Ι$\sub$trip/ for the ionomer/LDPE/CB composite decreased to a greater extent than that of the LDPE/CB composite. The average temperature coefficient of resistance (${\alpha}$$\sub$T/) for the polymer composites increased in the low-temperature region.

• Elastomers and Composites
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• v.58 no.3
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• pp.142-151
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• 2023

In this study, we investigate the thermal and mechanical properties of composites comprising ethylene propylene diene monomer (EPDM) and polybutadiene (PB) obtained using carbon black (CB) as a reinforcing and compatibilizing filler. Owing to the significance of elastomeric materials in various industrial applications, blending of EPDM and PB has emerged as a strategic method to optimize the material properties for specific applications. This study offers insights into the blend composition, its microstructure, and the resulting macroscopic behaviors, focusing on the synergetic effects of composite materials. Furthermore, this study delves into curing and rheological behaviors, crosslink densities, and mechanical, thermal, and elastic properties of the elastomeric composites. Through systematic exploration, we believe that this study will be beneficial to material scientists and engineers working on developing advanced elastomeric composites.