纺丝工艺对带形中间相沥青基石墨纤维取向结构及热导率的影响  

Effect of Spinning Process on the Oriented Structure and Thermal Conductivity of the Mesophase Pitch-based Graphite Fiber

作　　者：马兆昆[1] 刘朗[2] 刘杰[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029 [2]中国科学院山西煤炭化学研究所,太原030001

出　　处：《无机材料学报》2010年第9期989-993,共5页Journal of Inorganic Materials

基　　金：国家自然科学重点基金(50333070)~~

摘　　要：中间相沥青经熔融纺丝、不熔化、炭化石墨化制备了带状高导热石墨纤维.鉴于纺丝工艺对中间相分子的轴向和截面取向度的重要影响,研究了喷丝板结构和纺丝温度对中间相沥青基石墨纤维(MPGF)的取向结构和传导性能的影响.结果表明:对矩形截面喷丝的微孔,在最佳的纺丝温度下,截面长宽比越大,初生纤维内分子的取向度越高,MPGF的传导性越好.当长宽比和纺丝温度分别为9:1和305℃时,MPGF的取向度较高(97.8%),热导率达到894W/(m.K);长宽比继续增大时,更高的剪切作用致使纤维内应力较大,纺丝稳定性变差.High thermal conductive mesophase pitch-based graphite fiber was prepared through melt spinning,stabilization,carbonization and graphitization.It was proved that the spinning process was crucial for the degree of preferred orientation of mesophase molecular along the fiber axis.Effect of spinneret structure with rectangular section and spinning temperature on the preferred orientation degree and conductivity properties of MPGF were in-vestigated.The experimental results demonstrate that larger aspect ratio of spinneret section facilitate higher preferred orientation degree of molecular and conductivity.At 9：1 of the aspect ratio and 305℃ of spinning temperature,the orientation degree of graphite crystal with respect to fiber axis and thermal conductivity of MPGF reached 97.8% and 894 W/（m.K）,respectively.Furthermore,the mesophase pitch still exhibite good spinnability.With increasing the aspect ratio of rectangular section of spinneret,larger shear action leads to higher internal stress of fiber,and resultes in poor spinning stability.

关 键 词：中间相沥青基石墨纤维 取向结构 热导率 

分 类 号：TB332[一般工业技术—材料科学与工程]