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Song S.H.,Ulsan National Institute of Science and Technology | Kim J.M.,Korea Advanced Institute of Science and Technology | Park K.H.,Ulsan National Institute of Science and Technology | Lee D.J.,Korea Atomic Energy Research Institute | And 4 more authors.
RSC Advances | Year: 2015

Nano-fillers have provided a big advantage for enhancing the performance of rubber composites through leading the synergy effects in the physical and chemical properties. However, despite various approaches having been explored, the process to make a homogenous and stable dispersion of nano-filler in the rubber matrix remains a major challenge in this field. Herein, we propose a simple and effective route for synthesizing nanocomposites of rubber with homogenous and stable dispersed low defect graphene flakes (l-GFs), which are prepared using l-GFs/SBR composites via aqueous-phase mixing of exfoliated l-GFs with SBR latex. The l-GFs embedded SBR matrix shows a remarkable improvement in the modulus and tensile strength even at the low loading rate, which is ascribed to the efficient dispersion of the l-GFs enhancing interfacial interaction with the rubber matrix. The integration of l-GFs into the SBR matrix significantly improves the thermal and electrical conductivities, as well as the gas barrier property of the rubber composites. This method is water-mediated, green and scalable, showing great potential for the production of various l-GFs-based rubber composites at an industrial level. © The Royal Society of Chemistry 2015.

Kwon O.-S.,Tire Corporation Randnter | Lee D.,Korea Atomic Energy Research Institute | Lee S.P.,Tire Corporation Randnter | Kang Y.G.,Tire Corporation Randnter | And 2 more authors.
RSC Advances | Year: 2016

Hexagonal boron nitride nanoplatelets (BNNPs) can serve as two-dimensional (2D) fillers for elastomer nanocomposites due to their excellent and intriguing mechanical and thermal properties. Homogeneous and stable dispersion of BNNPs in elastomer is key to successful composite applications. Herein we propose a facile and easily industrialized approach for incorporating fully exfoliated BNNPs with hydroxyl functional groups into elastomer using the latex compounding method. The prepared BNNPs are highly dispersed in various solvents and their size of a few microns preserves their in-plane structure. The environmentally friendly, cost-effective, scalable preparation method proposed shows great potential for advancing the performance of elastomer nanocomposites. Specifically, the incorporation of BNNPs into the elastomer matrix remarkably improved the elastic modulus and tensile strength, even at low loadings; this was ascribed to the enhanced interfacial bonding of the BNNPs with the elastomer matrix. Moreover, well-dispersed BNNPs within the elastomer provided outstanding thermal conductivity and gas permeability. © 2016 The Royal Society of Chemistry.

Kim S.-W.,Nexen Tire Corporation R and nter | Jeong H.-K.,Nexen Tire Corporation R and nter | Kang Y.-G.,Nexen Tire Corporation R and nter | Han M.-H.,Nexen Tire Corporation R and nter
Asian Journal of Chemistry | Year: 2013

Rubber composites containing carbon black as a general fillers and multiwalled carbon nanotube, graphene and graphite as specific fillers were fabricated. Carbon materials were modified chemically and physically through an acid, heat and latex treatment to enhance the dispersion in rubber matrices. The acid, heat and latex treatment of carbon nanomaterials improved the mechanical properties, such as hardness, modulus, fatigue properties, electrical and thermal conductivity compared to pristine carbon materials. The modified graphene showed the most enhanced hardness, modulus and electrical conductivity but a significant decrease in the fatigue property and elongation. The modified carbon nanotube showed better thermal conductivity than the others, whereas the electrical and thermal conductivity of the nanocomposites decreased due to the formation of surface defects of multiwalled carbon nanotube by chopping.

Kim S.-W.,Tire Corporation R and nter | Jeong H.-K.,Tire Corporation R and nter | Kang Y.-G.,Tire Corporation R and nter | Han M.-H.,Tire Corporation R and nter
Asian Journal of Chemistry | Year: 2013

A tyre tread compound, showing good performance and high electrical conductivity, was prepared with a high silica loading and a low loading of multi-wall carbon nanotube in order not to sacrifice the original mechanical properties of the rubber compound. We fabricated styrene-butadiene rubber/natural rubber composites containing carbon black as a general filler and two types of multi-wall carbon nanotube with different structure and dimension, entangled carbon nanotube with short length (<10 μm) and parallel-aligned carbon nanotube bundles with a long length (<120 μm) as a specific filler. The incorporation of the aligned multi-wall carbon nanotube into the high silica rubber compound, even at low loading (0.5 phr), improved the static dissipation to a level that could meet the requirements (<108 ω) for tyres without a measurable decrease in the physical and dynamic properties. The abrasion resistance was also enhanced considerably by 15 % or more.

Park S.M.,Chonnam National University | Lim Y.W.,Chonnam National University | Kim C.H.,Tire Corporation R and nter | Kim D.J.,Tire Corporation R and nter | And 5 more authors.
Journal of Industrial and Engineering Chemistry | Year: 2013

Carbon nanotubes (CNTs) having three different lengths of 5, 30, and 100. μm were added to silica-filled styrene butadiene rubber (SBR) compounds in order to investigate the effect of the CNT addition on the dynamic and electrical properties. The amounts of CNTs were 1, 2, 4, and 7. phr, while the amount of silica was set high at 80. phr to clearly demonstrate the performance of the CNTs as fillers. The effect of CNTs on the silica-filled SBR compounds on the tensile properties is not significant, but the addition of longer CNTs with high loading severely deteriorated the dynamic properties, but considerably enhanced electrical conductivity. The medium loading of CNTs in silica-filled SBR compounds is suitable for the improvement of the electrical conductivity without severely sacrificing the dynamic properties. © 2012 The Korean Society of Industrial and Engineering Chemistry.

Shin E.-C.,Chonnam National University | Seo H.-H.,Chonnam National University | Kim J.-H.,Chonnam National University | Ahn P.-A.,Chonnam National University | And 9 more authors.
Polymer (United Kingdom) | Year: 2013

Percolating carbon conduction network is not only a long-time pursued scientific topic but also becomes more and more technologically important. Yet no established diagnostic tool is available. A simple two-wire transmission line (TL) model with symmetric boundary condition is suggested as working equivalent circuit model for the percolating carbon network in the insulating matrix such as polymer materials. Spatially distributed shunt capacitors of TL network are determined by the spacing between percolating backbone pathways of resistors. Deviation from the ideal RC TL behavior of the real network due to the non-uniform geometry, dangling network, random distribution of carbon fillers between the backbone pathways, etc. can be represented by modified yet parametric TL models featured by the generalization of the shunt capacitors to constant phase elements. © 2012 Elsevier Ltd. All rights reserved.

Song S.-H.,Tire corporation Randnter | Kwon O.,Tire corporation Randnter | Jeong H.-K.,Tire corporation Randnter | Kang Y.-G.,Tire corporation Randnter
Korean Journal of Materials Research | Year: 2010

The characteristics of all polymer composites containing carbon materials are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape. As a consequence, in this paper we discuss the aspects of the mechanical, electrical and thermal properties of composites with different fillers of carbon black, carbon nanotube (CNT), graphene and graphite and focus on the relationship between factors and properties, as mentioned above. Accordingly, we fabricate rubber composites that contain various carbon materials in carbon black-based and silica based-SBR matrixes with dual phase fillers and use scanning electron microscopy, Raman spectroscopy, a rhometer, an Instron tensile machine, and a thermal conductivity analyzer to evaluate composites' mechanical, fatigue, thermal, and electronic properties. In mechanical properties, hardness and 300%-modulus of graphene-composite are sharply increased in all cases due to the larger specific surface. Also, it has been found that the thermal conductivity of the CNT-composite is higher than that of any of the other composites and that the composite with graphene has the best electrical properties. © 2005 KISTI.

Song S.H.,Tire Corporation Randnter | Jeong H.K.,Tire Corporation Randnter | Gu K.Y.,Tire Corporation Randnter | Cho O.-T.,Tire Corporation Randnter
Polymer (Korea) | Year: 2010

The effects of acid-treated MWCNT and coupling agent on properties of MWCNT/SBR are investigated in this work. The MWCNTs oxidized using sulfuric and nitric acids were analyzed by the Raman scattering and Fourier transformed infrared spectroscopy(FT-IR). The FT-IR results indicate the presence of -COOH groups in the treated samples, and Raman spectroscopy of the acid-treated MWCNTs further corroborates the formation of surface defect due to the introduction of carboxyl groups. And the nanocomposites reinforced with MWCNTs were characterized extensively using the scanning electron microscopy (SEM), electrical conductivity, thermal conductivity, and tensile properties measurements. The results showed that nanocomposites onto acid-treated MWCNTs enhanced mechanical properties compared to those containing MWCNTs without acid treatment. These findings confirmed the improved interfacial interactions between MWCNTs and SBR arising from the coupling agents. But the electrical and thermal conductivity of nanocomposites decreased due to the chopping and formation of surface defects of MWCNTs.

Song S.H.,Tire Corporation R and nter | Jeong H.K.,Tire Corporation R and nter | Kang Y.G.,Tire Corporation R and nter
Journal of Industrial and Engineering Chemistry | Year: 2010

Nanocomposites consisting of styrene butadiene rubber (SBR) reinforced with the modified-graphite and natural-graphite with concentrations of 5. wt% were fabricated. Processing techniques such as acid treatment, thermal shock, sonication were employed in the fabrication of modified-graphite.The graphite platelets oxidized using sulfuric and nitric acids were analyzed by the Raman scattering, Fourier transformed infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The FT-IR results indicate the presence of acid groups in the treated samples, and Raman spectroscopy of acid-graphite platelets further corroborate the formation of surface defect due to the introduction of functional groups. However, the structure of XRD peaks did not change irrespective of processing techniques.The SBR-based nanocomposites were characterized using the scanning electron microscopy (SEM), rheometer, Instron tensile machine, thermal and electrical analyser.The results showed that nanocomposites onto acid-graphite platelets enhanced mechanical properties and fatigue properties of nanocomposites compared to those containing natural-graphite due to the increase in the interaction between the polymer and the modified-graphite. And the dynamic properties of nanocomposites had no influence according to the processing techniques. Also, thermal and electrical properties of nanocomposites using acid-graphite platelets were enhanced due to the broadened specific surface by the acid treatment. © 2010 The Korean Society of Industrial and Engineering Chemistry.

Song S.H.,Tire corporation R and nter | Jeong H.K.,Tire corporation R and nter | Kang Y.G.,Tire corporation R and nter | Cho C.T.,Tire corporation R and nter
Korean Journal of Chemical Engineering | Year: 2010

In general, carbon-based materials play a major role in today's science and technology and are required to advance with better properties to meet new requirements or to replace existing materials. We fabricated rubber composites reinforced with 5-weight% acid-graphite. The structural, mechanical and thermal properties of these composites were studied and compared. XRD studies indicated that the structure of the acid treated pristine-graphite (acid-graphite) did not change that of pristine graphite. Tensile properties of the composites indicated higher modulus, tensile strength and elongation in comparison with composites of pristine graphite, carbon black. Also, the composites were found to be in improving tendency with thermal properties and fatigue properties. The acid-graphite was investigated for surface morphology by scanning electron microscopy (SEM) and defects or purity by Raman spectroscopy. In this article, we discuss the influence of acid-graphite on rubber with high mechanical and thermal properties. © 2010 Korean Institute of Chemical Engineers, Seoul, Korea.

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