中介相沥青基碳纤维的性能

本文较系统地论述了中介相沥青基碳纤维的五种优异性能，包括力学性能，耐高温性能，热导及电导性能，尺寸稳定性能及编织性能，探讨了杨氏模量，热导率与电阻率之间的定性或定量关系，还综述了中介相沥青原料，温度和纤维形状对碳纤维电阻率的重要影响；指出中介相沥青基碳纤维是综合了优的高性能纤维之一。     

高性能中介相沥青基碳微球及碳片

综述了继中介相沥青基碳纤维之后新举起的中介相沥青基碳微球及碳片这两大类高级碳材料的制备方法，结构特征，优异性能和重要用途指出中介相尖青基碳微球具有高达５０００ｍ＾２／ｇ的比表面积和很高的表面活性，     

纺丝条件对沥青基碳纤维性能的影响

纺丝条件对沥青基碳纤维性能的影响Ｇ．Ｚ．ＬｉｕａｎｄＤ．Ｄ．Ｅｄｉｅ引言中间相沥青基碳纤维具有杨氏模量高，热导率大，密度小等优点。这种独特的性能使沥青基碳纤维得到竞相开发和应用。沥青基碳纤维的刚性及热导率与类石墨层沿纤维轴的择优取向有直接关系。因而，...     

中介相沥青基碳纤维的力学性能

系统地论述了高性能上沥青基碳纤维的力学性能及其与原料，纺丝工艺，氧化／碳化／石墨化温度、纤维形状及尺寸，超分子结构和环境温度等之间的关系，与其它高级液晶聚合物纤维和ＰＡＮ基碳纤维相比，中介相沥青基碳纤维显示较高的杨氏模量，抗压模量，抗张强度和抗压强度，最高可分别达１０２０ＧＰａ，７７０ＧＰａ，６．２ＧＰａ，３．５ＧＰａ。     

气相生长碳纤维增强水泥基复合材料的制备及性能

研究了脱油沥青(De-oiled asphalt)基气相生长碳纤维(VGCFs)增强水泥基复合材料的制备方法及其性能。以脱油沥青作原料,采用化学气相沉积法(CVD)制备出气相生长碳纤维,以此纤维制备水泥基功能复合材料。结果表明:低含量VGCFs的碳纤维增强水泥基复合材料具有良好的抗压强度和导电性能,在VGCFs的掺量由0增至0.6 %范围内,随着VGCFs掺量的增加,碳纤维增强水泥基复合材料的电阻率下降,抗压强度提高。当VGCFs为0.4 %时,VGCFs水泥基复合材料电阻率降低2个数量级,从3.25 ×105 Ω·cm 降为1.49 ×103 Ω· cm ,抗压强度提高28.8 %,为最佳掺量。      

中间相沥青基碳纤维原丝用油剂的研究现状

碳纤维已在众多领域发挥着越来越重要的作用，质量是其应用的保障，碳纤维原丝用油剂则是其中一个极其重要的质量把控点。经过多年的努力，我国中间相沥青基碳纤维已处于工程化开发进程中，因此亟需专用油剂以保障碳纤维产品的性能与质量。对国内外沥青基碳纤维原丝专用油剂的研究情况进行了总结和分析，具体涉及油剂分类、成分及其功能，以及上油工艺等，重点讨论了油剂成分及上油工艺的改进情况，并对我国中间相沥青纤维油剂今后的研发方向进行了探讨，以期为本行业的研究人员提供一定的帮助。     

沥青基碳纤维及其混杂纤维增强尼龙1010复合材料结构与性能的研究

本工作研究了通用型沥青基碳纤维、玻璃纤维及它们的混杂纤维增强尼龙1010复合材料的结构与性能,并与相应的聚丙烯腈基碳纤维及其混杂纤维复合材料的性能作了系统的比较.实验结果表明,随短纤维含量的增加,复合材料的模量和强度线性增加,当纤维含量达到一定临界值时,其强度有所下降.聚丙烯腈基碳纤维增强尼龙1010复合材料比相应的沥青基碳纤维复合材料具有较好的力学性能,但后者通过与高强度玻璃纤维混杂增强,可提高其力学性能.本工作还研究了这些复合材料的断裂特征和它们的混杂效应.      

中间相沥青基碳纤维石墨化度对Cf/Al界面损伤的影响

以不同石墨化度的中间相沥青基碳纤维为基底磁控溅射构筑Cf/Al界面,研究了不同石墨化度Cf/Al界面微观结构的演变,并与聚丙烯腈碳纤维比较揭示了Cf/Al界面的损伤机制。结果表明：随着石墨化处理温度的提高中间相沥青基碳纤维的石墨微晶尺寸增大、取向度和石墨化度提高,Cf/Al界面的反应程度降低和碳纤维损伤减少。不同石墨化度Cf/Al界面的损伤决定于初始缺陷的数量和后续裂纹在碳纤维内部的增殖和扩展。在2400℃和2700℃石墨化处理使裂纹更容易在中间相沥青基碳纤维石墨微晶片层间扩展,去除镀层后纤维损伤比聚丙烯腈碳纤维分别高5.19%和3.70%;在3000℃石墨化处理后,化学惰性较大的中间相沥青碳纤维使界面反应产生的缺陷数量大幅度减小,去除镀层后纤维的损伤比聚丙烯腈碳纤维低1.85%。     

正交试验法研究纺丝条件对中间相沥青碳纤维直径的影响

利用Taguchi正交试验方法探讨了沥青基碳纤维纺丝过程中影响纤维直径的纺丝工艺因素及其规律,结果表明:以纺丝温度、纺丝压力、卷筒转速和喷丝孔入口角等4个重要的纺丝工艺条件为考察因素时,卷筒转速是影响中间相沥青基碳纤维直径变化最重要的因素。中间相沥青基碳纤维直径随着喷丝孔入口角的增大而减小;随着纺丝温度的升高而增大;随着转速增大而明显减小。     

复合材料使用的增强纤维的现状与发展趋向

重点介绍了碳纤维、粘胶纤维基碳纤维、聚丙烯腈纤维基高强度高模量碳纤维、沥青碳纤维、陶瓷氧化物纤维、碳化硅纤维、高强度高模量有机纤维的开发、生产、应用现状与发展动向。     

Blending mesophase pitch to improve its properties as a precursor for carbon fibre Part 1 Blending of PVC pitch into coal tar and petroleum-derived mesophase pitches

The blending of mesophase pitch with isotropic PVC pitch was studied to improve their properties as a precursor for carbon fibre. PVC pitch prepared at 420° C which remained almost isotropic was found to be miscible with coal tar-derived mesophase pitch without reducing the anisotropic content and spinnability. The tensile strength of pitch fibres remained unchanged by the blending; however, the reactivity for stabilization was enhanced. The resultant carbon fibres from the blend exhibited slightly higher tensile strength. In contrast, petroleum-derived mesophase pitch failed to dissolve the PVC pitch, leaving a number of isotropic droplets. The structural factors of mesophase pitches with regard to their compatibility with PVC pitches are briefly discussed.     

基于分形理论的碳泡沫有效导热系数研究

以煤焦油基中间相沥青为原料，在一定的温度和压力条件下升温发泡，然后再经碳化、石墨化便可以制得一种高导热系数的多孔材料——碳泡沫。应用分形理论讨论了这种新型多孔材料的导热特性，推导出了碳泡沫的面积分形维数，并在此基础上建立了石墨化碳泡沫材料的导热模型，采用热阻法导出了石墨化碳泡沫材料的等效导热系数的关系式，计算出了碳泡沫的有效导热系数，计算结果与碳泡沫样品的实测值基本一致，这种方法为更好地利用其优良的导热性能提供了理论基础。     

Structure of mesophase pitch-based carbon fibres

The structure of five samples of commercially available carbon fibres with ultra-high modulus produced from mesophase pitch was studied by the complementary techniques of high resolution electronmicroscopy, X-ray diffraction and transverse magnetoresistance effect. The fibres with high strength and elongation to failure were found to be composed of turbostratic carbon structure, which was different from the three-dimensional graphite structure in ultra-high modulus carbon fibres. Transmission electron microscope examination revealed that the mesophase pitch-based fibres with high strength have a basic structure unit with folded sheets arranged nearly parallel to the fibre axis similar to those of high modulus carbon fibres produced from PAN. The present fold structure was suggested to contribute consequently to the lower graphitizability of the fibres and to the strong effects on the fibre strength. By controlling the microstructure, it is expected that the crystallographic as well as the mechanical properties could be improved significantly even from the same kind of precursor materials such as mesophase pitch.     

Improvement of thermal conductivity in 2D carbon–carbon composites by doping with TiC nanoparticles

Titanium-doped CC composites were prepared by liquid impregnation of a 2D carbon fibre preform using a mesophase pitch doped with TiC nanoparticles as matrix precursor. The effect of the addition of titanium carbide on the microstructure and thermal properties of CC composites is investigated. A higher degree of order was developed in the matrix of the Ti-doped composite which is the result of the catalytic graphitisation of carbon promoted by titanium. As a consequence, the thermal conductivity is higher in this doped material, despite the low dopant content introduced in the matrix, which points out the relevant contribution of the matrix to the thermal properties of the whole composite.     

Morphological structure study of pitch fibre surfaces by scanning tunnelling microscopy: influence of the mesophase content

The surface morphology of pitch fibres with different mesophase contents was studied by scanning tunnelling microscopy (STM) and the results were related to their mechanical properties. The tensile strength and modulus increase with the mesophase content and correspondingly the surface structure becomes more anisotropic. Inversely, the STM method can also be used to evaluate the precursor mesophase content of a pitch-based carbon fibre.     

Control of transversal texture in circular mesophase pitch-based carbon fibre using non-circular spinning nozzles

The transversal texture of circular-shaped carbon fibre was controlled by spinning the mesophase pitch through Y- or slit-shaped spinning nozzles. The flow direction of planar molecules along the non-circular nozzles was relaxed at their outlet into the circular shape, where the deformed texture was expected. Circular transversal shaped fibres with a random or a random-onion texture were successfully prepared by spinning the methylnaphthalene-based mesophase pitch through non-circular spinning nozzles. The spinning temperature which defines principally the viscosity of the molten pitch was the major factor to be controlled. Such carbon fibres exhibited greater strain to break and tensile strength than a fibre with a radial texture from the same pitch.     

导热型碳纤维增强聚合物基复合材料的研究进展

综述了导热型连续碳纤维增强聚合物基复合材料(CFRP)的研究与应用现状和进展,阐述了CFRP的声子导热和光子导热机理,介绍了不同铺层角度和铺层比的CFRP面内和厚度方向热导率计算模型及测试方法,分析了环氧树脂、氰酸酯、双马来酰亚胺等3类树脂体系和聚丙烯腈基(PAN)碳纤维、中间相沥青基碳纤维、气相生长碳纤维、碳纳米管纤维等4类增强体以及工艺方法等因素对CFRP热导率的影响。     

中间相沥青纤维制备高导热炭材料的研究

利用中间相沥青纤维中沥青分子的高度择优取向和适度的热塑性热压制备高导热块体炭材料. 对比研究了经不同氧化处理的带形及圆形中间相沥青纤维热压所得炭材料的传导性及力学性能. 结果表明: 相对圆形纤维来说, 由于带形中间相纤维具有更高的纤维轴向取向度和纤维之间更高的接触面积, 故其热压所得材料具有更高的密度和传导性. 经260℃氧化的带形纤维热压所得炭材料的密度、抗弯强度、电阻率及热导率分别达到了2.18g·cm^-3、118.4MPa、1.13μΩm和717W/m·K.     

Diamagnetic characterization of carbon fibres from pitch mesophase,pitch and polyacrylonitrile

The room temperature diamagnetic characteristics of carbon fibres from pitch mesophase (PM) have been determined and compared with those of fibres from isotropic pitch (P) and polyacrylonitrile (PAN) both in the as-processed condition and as a function of heat-treatment temperature over the approximate range 1000 to 3000° C. These fibre types show quite different magnetic behaviours indicative of different graphitizabilities which may be ranked PM, PAN, P in decreasing order. Microstructural and X-ray diffraction observations are also consistent with this ranking. Magnetic measurements provide a useful tool for characterization of fibre type and/or processing history.     

The effects of pressure on the carbonization of pitch and pitch/carbon fibre composites

Three pitches which give carbons of varying optical texture have been carbonized singly and with different carbon fibres at pressures in the range 0.1 to 200 MPa. The effect of pressure on the carbonization system is to retard growth and coalescence of the growth units of mesophase, thus reducing the size of the optical texture of the resultant carbon. With increasing pressure botryoidal (spherical) structures are formed. On co-carbonization of pitches with carbon fibres the alignment of the basal planes of the matrix carbon parallel to the fibre length at the fibre/matrix interface is improved within a given pressure range. This range is dependent upon the parent pitch used and is experimentally determined. This effect is seen for all fibre types.