Denitrogen and Graphitization Kinetics Analyze and Mechanism of Density Change for Polyacrynitrile-Based Carbon Fibers Heat Treated up to 2400oC
Tong Yuanjian1, Tong Xin2, Zhang Bowen3, Gao Aijun4, Xu Lianghua5
1Tong Yuanjian, State Key Laboratory of Organic-inorganic Composites, Beijing University of Chemical Technology, Beijing, China.
2Tong Xin, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, China.
3Zhang Bowen, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, China.
4Gao Aijun, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, China.
5Xu Lianghua, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, China.
Manuscript received on April 01, 2016. | Revised Manuscript received on April 09, 2016. | Manuscript published on April 15, 2016. | PP: 15-18 | Volume-4 Issue-4, April 2016. | Retrieval Number: D0976044416/2016©BEIESP
Open Access | Ethics and Policies | Cite
© The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Polyacrynitrile-based carbon fibers were continuously heat treated up to 2400oC under N2 atmosphere for different time. Element analyse, X-ray diffract spectrum and gradient column were used to determine the nitrogen content, crystal size and density of the resulted carbon fibers respectively. The density steadily decreased with increasing of temperature up to around 1700 oC, then increased quickly with further increasing of temperature. A mechanism of density change was proposed with respect to denitrogen reaction and graphite crystal growth during heat treatment. The kinetics parameters of the denitrogen reaction and the graphite crystal growth were calculated separately. By applying these kinetics parameters, bulk density of the carbon fibers treated at different temperature was predicted, which is in good accordance to the experimental data.
Keywords: Carbon fiber; Denitrogen; graphitization. Kinetics.