中文摘要：

采用FTIR、XRD、Raman等分析方法对在真空和氩气氛围中制备的聚丙烯腈炭膜化学结构和微晶结构的变化进行研究。结果表明，在两种氛围下PAN分子结构随着热解温度的升高由链状线型结构转变为乱层石墨结构，发生了氰基环化、脱氢、脱氮反应。PAN在真空氛围中的热解反应活化能低于氩气氛围中的活化能，说明真空氛围能够降低热解反应的温度，加速反应的进行。在真空氛围中制备的PAN炭膜微晶的La值大于氩气氛围中制备的炭膜微晶值，而d002、Lc。值则小于后者，说明真空氛围下制备的炭膜微晶有序度高，结构缺陷和孔隙均小于氩气氛围下制备的炭膜。可见，热解氛围对聚丙烯腈炭膜的热解机理、化学结构和碳微晶结构有很大的影响。

英文摘要：

The rnicrostructure of a polyacrylonitrile （PAN） carbon membrane prepared under vacuum or Ar atmosphere was studied by FTIR,XRD and Raman analysis. The change of chemical structure and formation of crystallites during the pyrolysis were also investigated. Results show that intra-chain cyclization, dehydration and denitrogenation occur during the pyrolysis. The microstructure of the PAN carbon membrane is transformed from a linear polymer to turbostratic carbon with increasing pyrolysis temperature. Compared with an Ar atmosphere, the pyrolysis of the PAN carbon membrane under vacuum has a low activation energy, i.e. the initial temperature of the pyrolytic reaction of a PAN carbon membrane can be decreased and the pyrolytic reaction rate can be accelerated under vacuum. In addition, the d002 ,Lc data of PAN carbon membranes prepared under vacuum are smaller while the La data are larger than those obtained under an Ar atmosphere. This indicates that the microstructural regularity of PAN carbon membranes prepared under vacuum are better than for those obtained under Ar, and structural defects and porosity are relatively large in the latter.