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Preparation and characterization of carbon/carbon composites with coal-tar pitch based carbon felt
양재연,고재경,김병석,서민강 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1
Carbon/carbon (C/C) composites are structural materials for use in structural applications at elevated temperatures due to the combination of their excellent mechanical properties and lower thermal expansion coefficient. Mechanical properties of the C/C composites depend on the matrix precursor and type of the carbon fibers used. Among these, the factor concerning carbon fibers plays an important role. In this study, C/C composites were made using type of the carbon fibers and resoltype phenolic resins. And effects of carbon fiber types on mechanical properties of the C/C composites were investigated by the three-point short-beam test according to the flexural strength and fractured C/C composites were examined under a scanning electron microscope (SEM).
Densification process of carbon/carbon composites by melted petroleum pitch impregnation
양재연,최웅기,곽이구,국윤수,서민강 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1
In this work, unidirectional carbon/carbon (C/C) composites with PAN-based carbon fibers as a reinforcement and phenolic and petroleum pitch resins as matrix precursors were densified by melted petroleum pitch impregnation and recarbonization. The effect of densification cycles of melted petroleum pitch impregnation was investigated. The efficiency of the impregnation process of the composites were observed by bulk density, open porosity. And the oxidation behaviors of the composites with densification cycles were investigated at 600-1000°C in an air environment. The mechanical properties and fracture behaviors of the composites were studied using the three-point short-beam test according to interlaminar shear strength and flexural tests. Relationships between the densification cycles and the brittle behaviors of the composites were also investigated.
Rapid stabilization of polyacrylonitrile-based carbon webs modified by ozone treatment
양재연,고재경,서민강 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0
Oxidative stabilization of PAN-based carbon webs were required to improve quality during the manufacturing process. Also, the oxidative stabilization process played a major role such as various reactions of the cyclization and intramolecular crosslinking. Recently, many efforts had been made to optimize the time and temperature profile of oxidative stabilization process. In this study, the oxidative stabilization process and microstructures of ozone-treated PAN-based webs were investigated. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray diffractomete (XRD), and scanning electron microscope (SEM) measurements were performed to characterize the stabilized fibers and carbon fibers.