硝酸法PAN基预氧丝在碳化期间分子结构的变化

利用气相色谱技术分离和鉴定了硝酸法ＰＡＮ基预氧丝在碳化期间所生成的主要特征气态组分ＣＯ２、ＣＯ、Ｏ２、Ｈ２Ｏ、Ｈ２、ＣＨ４、ＮＨ３、ＨＣＮ和Ｎ２以及它们在此过程中的变化规律。用Ｘ射线衍射技术测字该纤维在碳化过程中的微观结构的变化，研究了微晶参数与碳化温度之间的关系，同时，还用热重分析和元素分析手段考察了预氧丝的热裂解与分子组成变化的规律，提出了在此过程中大分子链段发生热解，形成环状分子交联和向层面

THE CHANGE OF MOLECULAR CONSTTTUTION OF PAN-BASED PREOCIDATIVE FIBER WITH NITRIC ACID WET-SPUN METHOD DURING THE CARBONIZATION

In this paper the volatile gaseous products formed during the carbonization of PAN-based preoxidative fiber with nitric acid wet-spun method were CO2,CO,O2,H2O, H2,CH4,NH3,HCN and N2,its were parted and examined by using gas chromatography technique, and have been studied the variations in which process. The microstructural change of this fiber during the thermal degradation has measured by means of the wide-angle X-ray diffraction technique.The relation between the microcrystal parameters and the carbonization temperature has studied.The variations of thermal decomposition and molecular composition of the preoxidative fiber were investigated using thermogravimetry and elemental analysis. The pyrolysis of the macromolecular chains occured and the cyclic molecular cross-linking to transition the lamellar network structure formed during carbonization process were suggested. Finally,the macromolecular solid residues with the rich carbon and the poor hydrogen of the polycyclic aromatic hydrocarbon condenced.