不同晶体取向中间相沥青基带状炭纤维的制备与表征

doi:10.15541/jim20140101

摘要/Abstract

摘要：

以中间相沥青为原料, 采用不同长宽比的矩形截面喷丝板, 通过控制熔融纺丝时的收丝速率, 制得了具有不同截面尺寸和晶体取向的高定向中间相沥青基带状炭纤维, 并研究了热处理温度和喷丝孔截面尺寸对所得炭纤维结构和性能的影响。结果表明, 喷丝孔的形状和收丝速度对炭纤维的晶体取向有显著影响。当收丝速度一定时, 随着喷丝孔截面长宽比的减小, 带状炭纤维截面碳晶体层片由褶皱平行取向结构向辐射状垂直取向结构转变。随着热处理温度的升高, 所制得炭纤维的室温轴向电阻率显著减小, 热导率相应增大, 力学性能明显提高; 随着收丝速率的增大, 带状炭纤维室温轴向电阻率变化不大, 但对其力学性能有显著影响。当喷丝孔截面长宽比和纺丝速度分别为30:1和75 m/min 时, 2500℃石墨化纤维的拉伸强度和杨氏模量分别为2.53 GPa和234.77 GPa。

关键词: 中间相沥青基带状炭纤维, 晶体取向, 电阻率, 力学性能

Abstract:

Using mesophase pitch as the raw material, with the rectangular-section spinnerets at different aspect ratios (length divided by width), ribbon-shaped mesophase pitch-based carbon fibers with various cross-section sizes and crystal orientations were prepared by adjusting the spinning rate. Effects of the heat-treatment temperature and aspect ratio of spinnerets on structure and properties of the ribbon-shaped carbon fibers were investigated. The results show that the aspect ratio of spinneret and the spinning rate of pitch fibers have a significant influence on the crystal orientation of carbon fibers. Within the specified spinning rate of pitch fibers, the crystal orientation of carbon fibers varies from a parallel-fold structure to a vertical-radial structure with the decrease of the aspect ratio of the spinnerets. The electrical conductivity and the mechanical property of ribbon-shaped carbon fibers significantly increase with the increase of heat-treatment temperature. With increase in spinning rate, there is no obvious change in the room-temperature axial electrical resistivity along the longitudinal direction of fiber, whereas obvious changes in the mechanical property are observed. At 30:1 of the aspect ratio of the spinneret and 75 m/min of spinning rate, the tensile strength and young’s modulus of the graphite fibers heat-treated at 2500℃ are up to 2.53 GPa and 234.77 GPa, respectively.

Key words: ribbon-shaped mesophase pitch-based carbon fiber, crystal orientation, electrical resistivity, mechanical property

中图分类号:

TB332

熊小庆, 袁观明, 李轩科, 董志军, 张中伟, 王俊山. 不同晶体取向中间相沥青基带状炭纤维的制备与表征[J]. 无机材料学报, 2014, 29(11): 1186-1192.

XIONG Xiao-Qing, YUAN Guan-Ming, LI Xuan-Ke, DONG Zhi-Jun, ZHANG Zhong-Wei, WANG Jun-Shan. Preparation and Characterization of Ribbon-shaped Mesophase Pitch-based Carbon Fibers with Different Crystal Orientations[J]. Journal of Inorganic Materials, 2014, 29(11): 1186-1192.

图/表 9

图1 喷丝孔的矩形截面示意图

Fig. 1 Diagram of rectangular-section of spinneret

表1 三个矩形喷丝孔的截面尺寸

Table 1 Dimensions and aspect ratios of three rectangular-section spinnerets

No.	L/mm	W/mm	L/W
a	3	0.1	30:1
b	2	0.4	5:1
c	1	0.4	2.5:1.0

图2 由不同喷丝孔制备的石墨化纤维(2500℃)的SEM照片(a1、b1 和c1)及其截面碳层取向示意图(a2、b2 和c2)

Fig. 2 SEM images (a1, b1 and c1) and carbon-layer orientation diagrams (a2, b2 and c2) of 2500℃ treated graphite fibers prepared from different spinnerets

图3 收丝速度与中间相沥青基炭纤维横截面积的关系

Fig. 3 Relationship between spinning rate and cross-sectional area of mesophase pitch based fiber

图4 经不同温度热处理(45 m/min收丝速度)(a)和不同收丝速度下制备的经2500℃处理(b)带状石墨纤维的XRD图谱

Fig. 4 XRD patterns of ribbon-shape graphite fibers prepared at the spinning rate of 45 m/min after heat-treatment at different temperatures (a) and prepared at various spinning rates after heat-treatment at 2500℃ (b)

表2 不同收丝速度制备的带状纤维于2500℃石墨化处理后的微晶参数

Table 2 Microcrystalline parameters of ribbon-shaped graphite fibers prepared at various spinning rates after heat-treatment at 2500℃

Spinning rate/(m·min^-1)	Peak width₍₀₀₂₎/(°)	d₀₀₂ /nm	L_c002/nm	g/%
15	0.3243	0.3373	24.88	77.8
30	0.3020	0.3373	26.72	78.4
45	0.3192	0.3374	25.28	76.7
60	0.3346	0.3376	24.11	74.9
75	0.3260	0.3374	24.11	76.2

图5 不同收丝速度下制备的石墨化纤维(2500℃热处理)的SEM照片及其碳层片取向示意图

Fig. 5 SEM images and carbon-layer orientation diagrams of graphite fibers prepared at different spinning rates after heat-treatment at 2500℃

图6 中间相沥青基炭纤维电阻率与收丝速率和热处理温度之间的关系

Fig. 6 Relationship between electrical resistivity and spinning rate as well as heat-treatment temperature

图7 炭纤维拉伸强度(a)和纤维杨氏模量(b)与收丝速度和热处理温度的关系

Fig. 7 Relationship of tensile strength (a) and young’s modulus (b) with spinning rate as well as heat-treatment temperature of ribbon-shaped carbon fibers

参考文献 21

[1]	LIU C Q, CHENG T, YU J M, et al. Preparation and study of mesophase pitch-based carbon firers. Carbon Techniques, 2002(5): 1-4.
[2]	CALLEGO N C, EDIE D D. Structure-property relationships for high thermal conductivity carbon fibers. Composites: Part A, 2001, 32(8): 1031-1038.
[3]	QIU H P, LIU L. Carbon matrix function materials of high thermal conductivity. New Carbon Materials, 2002, 17(4): 80.
[4]	QIU H P, GUO Q G, SONG Y Z, et al. Study of the relationship between thermal conductivity and microcrystalline parameters of bulk graphite. New Carbon Materials, 2002, 17(1): 36-40.
[5]	LIU J Q, SHI J L, GAO X Q.et al. The study on formation mechanism of radial structure of mesophase pitch-based carbon fibers. New Carbon Materials, 2010, 19(2): 19-87.
[6]	CHI W D, SHEN Z M, LIU J, et al. Influence of spinneret constructure on the section shape of non-circle shape mesophase bitch-based fiber. Carbon Techniques, 1999, 5: 5-8.
[7]	LI M W, WANG C Y. Preparation and properties of mesophase pitch-based ribbon-shaped carbon fibers. Chinese Journal of Materials Research, 1998, 12(5): 535-538.
[8]	EDIE D D, ROBBINSON K E, FLEUROT O, et al. High thermal conductivity ribbon fibers from naphthalene-based mesophase. Carbon, 1994, 32(6): 1045-1054.
[9]	EDIE D D, HAYES G J, RAST H E, et al. Processing of noncircular pitch-based carbon fiber. High Temperatures-High Pressure, 1990, 22: 289-298.
[10]	MOCHIDA I, YOON S H, KORAI Y. Control of transversal texture in circular mesophase pitch-based carbon fiber using noncircular spinning nozzles. Journal of Materials Science, 1993, 28(9): 2331-2336.
[11]	LU S L, BRIAN RAND. Large diameter carbon filaments from mesophase pitch for thermal management applications. New Carbon Materials, 2000, 15(1): 1-5.
[12]	MOCHIDA I, YOON S H, KORAI Y. Preparation and structure of mesophase pitch-based thin carbon tape. Carbon, 1993, 31(6): 941-949.
[13]	ROBINSON K K, EDIE D D. Microstructure and texture of ribbon fibers for thermal management. Carbon, 1996, 34(1): 11-36.
[14]	LI M W, WANG C Y. Research and applications of mesophase pitch-based carbon fibers. Carbon Techniques, 1998, 2: 31-35.
[15]	FORTIN F, YOON S H, KORAI Y, et al. Structure and properties of thin, slit-shaped carbon fibers prepared from mesophase pitch. Carbon, 1994, 32(6): 1119-1127.
[16]	EDIE D D, FAIN C C, ROBINSON C C, et al. Ribbon-shaped carbon fibers for thermal management. Carbon, 1993, 31(6): 941-949.
[17]	MA Z K, LIU L, LIU J. Effect of spinning process on the oriented structure and thermal conductivity of the mesophase pitch-based graphite friber. Journal of Inorganic Materials, 2010, 25(10): 989-993.
[18]	YUAN G M, LI X K, DONG Z J, et al. Preparation and characterization of highly oriented ribbon shape pitch-based carbon fibers. Journal of Inorganic Materials, 2011, 26(10): 1025-1030.
[19]	YUAN G M, LI X K, DONG Z J, et al. The structure and properties of ribbon-shaped carbon fibers with high orientation. Carbon, 2014, 68: 426-439.
[20]	YUAN G M, LI X K, DONG Z J, et al. Microstructure analyses of mesophase pitch-based carbon fibers with high thermal conductivity. Journal of Functional Materials, 2011, 42(10): 1806-1809.
[21]	ZHANG X, FUJIWARA S, FUJII M. Measurement of thermal conductivity and electrical resistivity of a single carbon fiber. Inter. J. Thermophys, 2000, 21(4): 965-980.