Preparation of High Performance Carbon Blocks Via Self-sintering of MCMBs: Improving the Quality of Products by Reaction-promoting Additives

• Main Authors: Yu-Heng Yeh, 葉育亨
• Other Authors: Jiin-Jiang Jow
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/40132096991865094287

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 101 === The effects of various reaction-promoting additives, including terephthalic aldehyde (TPA), carbon black (CB), glycidyl methacrylate (GMA), phenol, polysufone (PSF) and benzoyl peroxide (BPO), on the sintering behavior of mesocarbon-microbeads (MCMBs) materials and mechanical properties of the carbon blocks were investigated for manufacture of high quality carbon products. Thermogravimetric analysis (TGA/DTA), molecular weight distribution and composition analysis, scanning electron microscopy (SEM), pycnometry and bending strength test were used for the study. The molecular weight distribution and composition analysis results show that the ratio of high molecular weight components in the solid-resin with heatreatment at 190 and 210 ℃ was reduced in the presence of GMA and CB. This indicates that the condensation reaction of the materials occurs at around 200℃, which decreases the fluidity and sinterability of the material mixtures, was inhibited by the additives. The TGA/DTA results, showing a smaller weight loss peak (-dW/dT) at around 200℃, also demonstrate similar phrnamena. In addition, the TGA/DTA curves also show that the -dW/dT peak due to pyrolysis reaction of the materials at around 300-550℃reduced in the presence of the GMA, while the peak shifted to a lower temperature range when the CB was added in the raw materials. Besides, the TGA/DTA for sintering of MCMB in the presence of the PSF and BPO additives indicates that the PSF and BPO additives promote the reactions at around 200 and 300-550℃, respectively. These results reveal that the promoting effects vary with the different additives. Additionally, dual additives, CB and GMA were further used to modify the sintering behavior of MCMB raw materials and improve the quality of the MCMB based carbon blocks. The results indicate that there is a mutual additive effect of the dual CB and GMA additives on the improving effects on the sintering reaction of the MCMB materials for manufacture of high quality carbon blocks. The GMA inhibits the formation of pyrolysis volatile gas during the sintering of the MCMB raw materials at around 300 – 550 °C, while the CB accelerates the pyrolysis reactions and shifts the temperature of the occurrence of the volatile gas to a lower range. The mechanical properties of the MCMB based carbon products are significantly improved in the presence of the dual additives. High quality carbon blocks with a bending strength of 142 MPa and a density of 1.87 g cm-3 were obtained after carbonization at 1000 °C. The maximum bending strength and density of the carbonized samples with the dual CB and GMA additives is 50% and 7 % higher, respectively, than that without the dual additives. Keyword: MCMBs, β-resin, TPA, CB, GMA, Phenol, PSF, BPO, self-sintering.