以聚酰亚胺( PI)纤维为前驱体,经800~2800益连续高温处理,制备出不同性能的聚酰亚胺基炭(石墨)纤维。采用元素分析、SEM、HRˉTEM、Raman、纤维强力仪、电阻率仪等分析手段研究热处理温度对炭纤维( CF)元素含量、结构形貌、力学性能、传导性能等方面的影响。结果表明,随着热处理温度的升高,聚酰亚胺基炭纤维中碳含量从78.97%(800益)提高到99.72%(2800益),非碳原子含量降低；聚酰亚胺基炭纤维表面缺陷数目增加且尺寸增大。同时,纤维的微观结构也从二维乱层石墨结构向有序的三维层状结构发展,表现为石墨化程度的提高及石墨微晶尺寸的增大；炭纤维拉伸强度先增加后降低,最大拉伸强度924.4 MPa,断裂伸长率降低,电阻率减小,热导率增加,2800益石墨化处理后纤维热导率为228.4 W·m-1·K-1,是800益处理后的50.4倍。
Polyimide( PI) ˉbased carbon fibers with different properties were prepared by carbonization of PI fibers at 800 ℃, folˉ lowed by heat treatment from 800 to 2 800 ℃. The effect of heat treatment temperature ( HTT) on elemental composition, surface morphology, mechanical properties, and the thermal and electrical conductivities of PIˉbased carbon fibers were investigated by eleˉ mental analysis, SEM, HRTEM, Raman spectroscopy, mechanical testing, and electrical and thermal conductivity measurements. Results showed that as a result of HTT the carbon content increased from 78. 97% to 99. 72%, the tensile strength exhibited a maxiˉ mum of 924. 4 MPa, and the degree of graphitization and the size of graphite crystallites were both increased. Distinct reductions in strainˉtoˉfailure and electrical resistivity were observed with increasing HTT. The thermal conductivity can reach 228. 4 W·m-1·K-1 after heat treatment at 2 800 ℃. PI fiber may be a good precursor for carbon fibers with a high thermal conductivity.
参考文献
| [1] | 李同起,胡子君.定向高导热碳材料及其热管理结构设计[J].宇航材料工艺,2007(01):16-18,22. |
| [2] | Druma A M;Alam M K;Druma C .Analysis of thermal conducˉ tion in carbon foams[J].International Journal of thermal Sciˉ ence,2004,5:689-695. |
| [3] | J. Che;T. Cagin .Thermal conductivity of carbon nanotubes[J].Nanotechnology,2000(2):65-69. |
| [4] | Adams PM.;Rellick GS.;Stupian GW.;Katzman HA. .Characterization of high thermal conductivity carbon fibers and a self-reinforced graphite panel[J].Carbon: An International Journal Sponsored by the American Carbon Society,1998(3):233-245. |
| [5] | Murakami M;Nishiki K;Knakamura K et al.Yoshmura. highˉ quality and highly oriented graphite block from polycondensation polymer films[J].CARBON,1992,30(02):255-262. |
| [6] | 赵根祥,邱海鹏.聚酰亚胺基碳纤维的开发[J].合成纤维工业,2000(01):71-74. |
| [7] | Gajanan S B;RenataSch W.Conversion of a copolyimide fiber into carbon fiber[A].The American Carbon Society,1997:406. |
| [8] | Seung K P;Richard J F .Dryˉjet wet spinning of aromatic polyˉ amide acid fiber using chemical imidization[J].POLYMER,2001,42:10087-10093. |
| [9] | Zhang QH;Dai M;Ding MX;Chen D;Gao LX .Mechanical properties of BPDA-ODA polyimide fibers[J].European Polymer Journal,2004(11):2487-2493. |
| [10] | Tuinstra F;Koenig J L .Raman spectrum of graphite[J].Jourˉ nal of Chemical Physics,1970,53(03):1126-1130. |
| [11] | Zhang X;Fujiwara S;Fujii M .Measurement of thermal conˉ ductivity and electrical resistivity of a single carbon fiber[J].International Journal of Thermophysics,2000,21(04):965-980. |
| [12] | 王浩静,王红飞,李东风,朱星明,贺福,王心葵.石墨化温度对炭纤维微观结构及其力学性能的影响[J].新型炭材料,2005(02):157-163. |
| [13] | Watt W;Johnson W .A research on the carbonization process of PANˉbased precursor fiber[J].Polymer Prepr,1968,9(02):1245-1248. |
| [14] | 赵根祥;贾世军;钱树安 .PI膜转变为碳膜过程中的结构变化[J].碳素技术,1997,91(05):12-17. |
| [15] | Hatori H.;Shiraishi M.;Yoshihara M.;Kimura T.;Yamada Y. .THE MECHANISM OF POLYIMIDE PYROLYSIS IN THE EARLY STAGE[J].Carbon: An International Journal Sponsored by the American Carbon Society,1996(2):201-208. |
| [16] | 贺福.用拉曼光谱研究碳纤维的结构[J].高科技纤维与应用,2005(06):20-25. |
| [17] | Ferrari AC;Meyer JC;Scardaci V;Casiraghi C;Lazzeri M;Mauri F;Piscanec S;Jiang D;Novoselov KS;Roth S .Raman spectrum of graphene and graphene layers[J].Physical review letters,2006(18):7401-1-7401-4-0. |
| [18] | 贺福,杨永岗.提高碳纤维强度的理论基础及其技术途径[J].高科技纤维与应用,2001(02):7-10,32. |
| [19] | Lavin J G;Boyington D R;Lahijani J et al.The correlation of thermal conductivity with electrical resistivity in mesophase pitchˉbased carbon fiber[J].CARBON,1993,31(06):1001-1002. |
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