摘要
在室温条件下,以不同浓度的HNO3溶液(质量分数分别为10,20,30 and 40%)为氧化介质处理沥青球,而后直接进行高温炭化处理,利用FT-IR、XPS、SEM和元素分析表征HNO3氧化沥青球及其炭化样的化学结构和表面形貌。结果表明:用30%HNO3氧化12h的沥青球在900℃高温炭化后能够保持良好的球形度和表面形貌;HNO3处理引入的-NO2官能团在400℃前转化为胺基,促进了沥青分子的交联,保证了沥青球炭化过程的顺利进行;当炭化温度为900℃时,胺基进一步发生了环化和芳构化反应,氮原子以吡啶氮和季氮形式存在。
Pitch spheres were stabilized by HNO3 oxidation at room temperature using HNO3 solutions of 10,20,30,and 40% mass fraction. The chemical structure and morphology changes of the oxidized pitch spheres and their carbo￣nized samples were investigated by FT-IR,XPS,elemental analysis,and SEM. Results showed that the pitch spheres oxidized by 30% HNO3 for 12 h could be carbonized at 900 ℃ to produce carbonized spheres without any change in shape. The successful carbonization can be ascribed to the contribution of nitrogen functional groups in the form of -NO2,which were introduced in the HNO3 oxidation process. In the early stage of the heat treatment around 400 ℃,the transformation of -NO2 groups to amine groups occurred,which promoted the cross-linking of pitch molecules. As the pitch spheres were carbonized at 900 ℃,cyclization and aromatization reactions led to the formation of pyridine and quaternary nitrogen groups.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2010年第1期29-34,共6页
New Carbon Materials
基金
Nature Science Foundation of China (50672025)
Science and Technology Commission of Shanghai Municipality (065258033,06DZ22003)~~
