ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Mesophase pitch (MPP) has a high carbon yield and excellent graphitizability, compared withcommercial coal tar pitch (CTP), which make it suitable for the preparation of C/C composites. In this paper,two MPP were prepared by heat-treatment of two coal tar pitches (CTP and modified coal tar pitch (MCTP)) inthe presence of nitrogen. Elemental analysis and FTIR were used to monitor the change of chemical structuresof MPP transition from CTP and MCTP. The pyrolysis behaviors of CTP and MCTP were studied by meansof thermal analysis (TG and DSC). The morphologies of MPP were inspected by optical microscope. Thestructures of the MPP were characterized by XRD. The results show that there are more alkyl functional groupsexisting in CTP and MCTP than in MPP, and MPP has a higher C/H ratio than CTP and MCTP, whichindicate MPP formation predominantly polycondense aromatic and release the alkyl functional groups. Anendothermic band due to volatilize light compounds around 290 °C, two exothermic peaks at 430°C and 490°C were characteristic of polymerization reactions, exothermic peaks of MCTP are higher than that of CTPbecause the former has a higher reaction active for its more alkyl side chain. The optical texture of MPP fromCTP is mosaics texture, while from the MCTP is flow domains texture. (002), (101) peaks of graphite occur onXRD patterns, the peaks of MPP from MCTP are higher and narrower than MPP from CTP, which indicatesthe former is more graphitizability than the latter
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.334-335.165.pdf
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