석탄계 타르의 열처리 중 압력변화에 따른 변성 콜타르 핏치의 미세구조 및 물성 변화 = Changes of Microstructure and Properties of Manufactured Modified Pitches via Pressure Changes during Heat Treatments in Coal Tar Pitch

다국어 초록 (Multilingual Abstract)

Coal-tar pitch, a feedstock which can be heat-treated to create graphite, is composed of very complex molecules. Coal-tar pitch is a precursor of many useful carbon materials (e.g., graphite, carbon fibers, electrodes and matrices of carbon/carbon composites). Modified coal-tar pitch (MCTP) was prepared using two different heat-treatment methods and their properties were characterized and compared. One was prepared using heat treatment in nitrogen gas; the other was prepared under a pressure of 350 mmHg in air. The MCTPs were investigated to determine several properties, including softening point, C/H ratio, coke yield, formation of anisotropic mesophase and viscosity. The MCTPs were subject to considerable changes in chemical composition due to condensation and polymerization in the used-as-received coal-tar pitch after heat-treatment under different conditions. The MCTPs showed considerable increases in softening point, C/H ratio, and coke yield, compared to those of as-received coal-tar pitch. The MCTP formed by heat-treatment in nitrogen showed isotropic phases below $350^{\circ}C$ for 1 h of soaking time. However, MCTP heat-treated under high pressure (350 mmHg) showed isotropic phases below $300^{\circ}C$, and showed anisotropic phases above $350^{\circ}C$, for 1 h of soaking time. The viscosity of the MCTPs increased with increase in their softening points.

참고문헌 (Reference)

1 B. Yu, 104 : 155-, 2012

2 S. M. Zeng, 31 (31): 413-, 1993

3 J. B. Barr, 16 (16): 439-, 1978

4 C. Blanco, 38 (38): 517-, 2000

5 I. C. Lewis, 18 (18): 191-, 1980

6 B. Petrova, 43 (43): 261-, 2005

7 K. H. Kochling, 23 (23): 601-, 1985

8 J. B. Barr, 16 (16): 439-, 1978

9 R. Menendez, 36 (36): 973-, 1998

10 T. Maeda, 31 (31): 407-, 1993

11 P. M. Khandare, 38 (38): 889-, 2000

12 A. D. Cato, 41 (41): 1411-, 2003

13 S. R. Hlatshwayo, 51 (51): 64-, 2013