【作者】 宋鹏；

【导师】 王丽；

【作者基本信息】 山东大学 ， 机械工程（专业学位）， 2013， 硕士

【摘要】 本文以透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、红外吸收光谱(IR)分析仪和元素分析仪等为主要手段,并借助密度和张力等测试技术,研究了不同聚合单体对原丝性能的影响,并进一步研究了不同单体聚合制得原丝与碳纤维性能之间的关系,以及不同制备工艺对PAN基碳纤维性能的影响,从而为高性能碳纤维的制备提供借鉴。主要研究内容如下：不同聚合工艺中以丙稀腈、衣康酸盐、衣康酸二甲酯为聚合单体所制得的碳纤维强度均较低。相同聚合工艺中,原丝的纤度的大小对制得碳纤维的强度有一定的影响。原丝纤度大,制得的碳纤维强度也较大,原丝的纤度在适当范围内的增大能够增加制得的碳纤维的强度。通过不同的预氧化工艺和碳化工艺,研究了各阶段纤维强度和微观结构之间的关系。发现在预氧化的低温阶段施加适当的牵伸,高温阶段保持纤维定长,能够获得较高强度的碳纤维,反之则会使碳纤维的强度降低。在碳化过程中对中低温碳化施加适当的正牵伸能够提高碳纤维的力学性能。在预氧化碳化过程中,从纤维强度来看,预氧丝的强度最低,预氧丝碳化至碳纤维过程中强度急剧上升。可见预氧丝是碳纤维制备过程中强度最薄弱的环节。原丝的结构在很大程度上存在着遗传性,这种遗传性表征在制得的碳纤维中有着明显的体现。在碳纤维制取的整个过程中,纤维的形态结构特征,如原丝的内部结构、含碳量等在制得的碳纤维中有所保留。碳纤维表皮组织中的沟槽随原丝预氧化温度的升高而变小,因此预氧化碳化工艺需根据原丝的性能来进行设定。更多还原

【Abstract】 The evolution of structure and changes of properties during the spinning, thermal stabilization, and carbonization of PAN precursor have been studied by many techniques, such as Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Wide Angle X-ray Diffraction (WAXD), Infrared Spectroscopy (IR) and Elemental Analyzer. The tension and density of fibers at different stages were also tested in this paper.Main research contents are as follows:The relationship between properties of different precursor fibers and carbon fibers is studied. We find that through different polymerization systems, the strength of carbon fibers using propylene nitrile, dimethyl itaconic acid, and itaconic acid salt as precursor fiber is low, and the fiber linear density change is bigger. Under same polymerization process, the size of the original silk has a positive relationship with the strength of the carbon fiber.Through different preoxidation process and carbonization process, the relationship between the fiber structure and properties of representation is studied. We find that in the oxidation of low temperature stage applying proper drafting, while high-temperature phase keep fiber fixed length, the intensity of carbon fiber is higher, and the opposite will reduce the strength of the carbon fiber. Under400℃low temperature carbonization process, the strength of the fiber can not be improved, while500℃to600℃of carbonization temperature is suitable for increasing carbon fiber strength.During oxidation and carbonization processes, the strength of PAN precursor fibers is the lowest. PAN precursor fibers are the weakest link during the preparation of carbon fiber fabrication. The internal structure of precursor fibers and carbon content have hereditary on carbon fibers.The groove on the surface of fibers will be smaller with the higher preoxidation temperature. Therefore the oxidation, carbonization processes of precursor fiber should be carried out according to the performance of the original silk.更多还原