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Mesophase formation behavior in petroleum residues
Subhash Kumar, Manoj Srivastava 한국탄소학회 Carbon Letters 12 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.3 3 171-182 (12 pages)
Mesophase pitch is an important starting material for making a wide spectrum of industrial and advanced carbon products. It is produced by pyrolysis of petroleum residues. In this work, mesophase formation behavior in petroleum residues was studied to prepare environmentally- benign mesophase pitches, and the composition of petroleum residues and its influence on the mesophase formation was investigated. Two petroleum residues, i.e., clarified oil s (CLO-1, CLO-2) obtained from fluid catalytic... -
Effects of cross-linking methods for polyethylene-based carbon fibers: review
Kwan-Woo Kim, Hye-Min Lee, Jeong-Hun An, Byoung-Suhk Kim, Byung-Gak Min, Shin-Jae Kang, Kay-Hyeok An, Byung-Joo Kim 한국탄소학회 Carbon Letters 24 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.3 2 147-170 (24 pages)
In recent decades, there has been an increasing interest in the use of carbon fiber reinforced plastic (CFRP) in aerospace, renewable energy and other industries, due to its low weight and relatively good mechanical properties compared with traditional metals. However, due to the high cost of petroleum-based precursors and their associated processing costs, CF remains a specialty product and as such has been limited to use in high-end aerospace, sporting goods, automotive, and specialist... -
Bulk graphite: materials and manufacturing process
Sang-Min Lee, Dong-Su Kang and Jea-Seung Roh 한국탄소학회 Carbon Letters 12 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.3 1 135-146 (12 pages)
Graphite can be classified into natural graphite from mines and artificial graphite. Due to its outstanding properties such as light weight, thermal resistance, electrical conductivity, thermal conductivity, chemical stability, and high-temperature strength, artificial graphite is used across various industries in powder form and bulk form. Artificial graphite of powder form is usually used as anode materials for secondary cells, while artificial graphite of bulk form is used in steelmaking... -
Changes in the porosity of bulk graphite according to the viscosity of resin for impregnation
Sang-Min Lee, Dong-Su Kang, Hye-Sung Kim, Jea-Seung Roh 한국탄소학회 Carbon Letters 3 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.2 10 132-134 (3 pages)
in the carbonization process through pressurization and/or depressurization. The physical properties of bulk graphite that has undergone impregnation and re-carbonization processes are outstanding. In the present study, a green body was manufactured by molding with natural graphite flakes and phenolic resin at 45 MPa. Bulk graphite was manufactured by carbonizing the green body at 700 and it was subsequently impregnated with impregnants having viscosity of 25.0 cP, 10.3 cP, and 5.1 cP, and the... -
Stabilization of pitch-based carbon fibers accompanying electron beam irradiation and their mechanical properties
Mi-Seon Park, Yoonyoung Ko, Min-Jung Jung, Young-Seak Lee 한국탄소학회 Carbon Letters 6 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.2 8 121-126 (6 pages)
Carbon fibers are prepared by stabilizing pitch fibers accompanying electron beam (E-beam) irradiation. The carbon fibers pretreated by E-beam irradiation achieve a higher stabilization index than the carbon fibers that are only heat-stabilized. In addition, the carbon fibers subjected to E-beam irradiation in the stabilization step exhibit a comparable tensile strength to that of general purpose carbon fibers. The carbon fibers pretreated with an absorbed dose of 3000 kGy have a tensile... -
Activated carbons prepared from mixtures of coal tar pitch and petroleum pitch and their electrochemical performance as electrode materials for electric double-layer capacitor
Eunji Lee, Soon Hyung Kwon, Poo Reum Choi, Ji Chul Jung, Myung-Soo Kim 한국탄소학회 Carbon Letters 8 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.2 2 78-85 (8 pages)
Activated carbons (ACs) were prepared by activation of coal tar pitch (CTP) in the range of 700°C-1000°C for 1-4 h using potassium hydroxide (KOH) powder as the activation agent. The optimal activation conditions were determined to be a CTP/KOH ratio of 1:4, activation temperature of 900°C, and activation time of 3 h. The obtained ACs showed increased pore size distribution in the range of 1 to 2 nm and the highest specific capacitance of 122 F/g in a two-electrode system with an organic... -
Preparation and thermal properties of polyethylene-based carbonized fibers
Kwan-Woo Kim, Hye-min Lee, Byoung Suhk Kim, Seon-Hwan Hwang, Lee-Ku Kwac, Kay-Hyeok An and Byung-Joo Kim 한국탄소학회 Carbon Letters 5 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.1 10 62-66 (5 pages)
were studied using thermal analyses such as DSC and TGA. The melting and heating enthalpy of the fibers decreased as the cross-linking temperature increased. The cross-linked fibers had a carbonization yield of over 50%. From SEM results the highest yield of carbonized LDPE-based fibers was obtained by cross-linking at a sulfate temperature (170oC). As a result, carbonation yield of the carbonized fibers was found to depend on the functions of the cross-linking ratio of the LDPE precursors. -
Influence of hot-pressing pressure on the densification of short-carbon-fiber-reinforced, randomly oriented carbon/carbon composite
Thakur Sudesh Kumar Raunija and Sharad Chandra Sharma 한국탄소학회 Carbon Letters 9 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.1 4 25-33 (9 pages)
The prime objective of this research was to study the influence of hot-pressing pressure and matrix-to-reinforcement ratio on the densification of short-carbon-fiber-reinforced, randomly oriented carbon/carbon-composite. Secondary objectives included determination of the physical and mechanical properties of the resulting composite. The ‘hybrid carbon-fiberreinforced mesophase-pitch-derived carbon-matrix’ composite was fabricated by hot pressing. During hot pressing, pressure was varied from 5... -
An overview of new oxidation methods for polyacrylonitrile?based carbon fibers
Hye Kyoung Shin, Mira Park, Hak-Yong Kim and Soo-Jin Park 한국탄소학회 Carbon Letters 8 Pages
한국탄소학회 Carbon Letters 2015, Vol.16 No.1 2 11-18 (8 pages)
The process of oxidizing polyacrylonitrile (PAN)-based carbon fibers converts them into an infusible and non-flammable state prior to carbonization. This represents one of the most important stages in determining the mechanical properties of the final carbon fibers, but the most commonly used methods, such as thermal treatment (200°C to 300°C), tend to waste a great deal of process time, money, and energy. There is therefore a need to develop more advanced oxidation methods for PAN precursor... -
Novel reforming of pyrolized fuel oil by electron beam radiation for pitch production
Jin-Young Jung, Mi-Seon Park, Min Il Kim and Young-Seak Lee 한국탄소학회 Carbon Letters 6 Pages
한국탄소학회 Carbon Letters 2014, Vol.15 No.4 5 262-267 (6 pages)
molecular weight, solubility, softening point, and density increased in proportion to the absorbed dose of E-beam radiation, with the exception of the highest absorbed dose, due to modification by free radical polymerization and the powerful energy intensity of E-beam treatment. The H/C ratio and yield exhibited the opposite trend for the same reason. These results indicate that novel E-beam radiation reforming is suitable for the preparation of aromatic pitch with a high β-resin content.
