有机先驱体法制备h-BNC/石墨烯纳米复相陶瓷与微观机制研究

碳基复合材料是由石墨相和增强相构成的高技术新型高温材料，它在航空航天器结构部件、高温密封部件等发挥着关键作用。目前碳基复合材料的不足之处主要有：抗高温氧化性能差；受原料性质的影响，难以制备各种复杂的异型件。本项目提出一种采用有机先驱体制备六方BNC/石墨烯纳米复相陶瓷的新方法。其核心是利用含有B-N六元环结构的三氯硼吖嗪和含有两个活泼氢原子的苯胺反应，再与石墨烯原位聚合得到聚合度可控的线形BNC先驱体高聚物，进而在氮气气氛下陶瓷化处理，从而获得可定量控制B、N、C原子数目的纳米复相陶瓷。该方法与制备BN纤维采用的有机先驱体法有相似之处。本项目将重点研究热处理过程中B-N六元环、B-N-C键的演化机制和温度对六方BNC析晶行为的影响，揭示BNC先驱体-陶瓷结构演化机制。该项目的实施将会解决碳基复合材料的成型问题和在一定程度上提高材料的抗高温氧化性能。

Carbon substrate composite material is a new advanced high temperature resistance material comprising graphite and reenforcement fillers which takes key importance in aerospace structural components and high temperature sealing stuff. Recently the main drawbacks of the carbon substrate composite material are: unsatisfactory high temperature resistance performance; difficult to prepare complex heterotypic parts controlled by the raw materials performance. A novel organic precursor route is developed in this project to prepare h-BNC/graphene nano structure composite ceramics. The key technology in this project is to polymerize the trichloroborazine containing hexagonal B-N rings with the aniline which has double reactive hydrogen atoms, then insitu polymerize them with graphene to obtain controllable line-type BNC polymer. After that the precursor is pyrolyzed in nitrogen atmosphere to obtain atom controllable BNC composite. This method is similar with the process to prepare BN fiber by organic precursor. The main targets of the project is to research the evolution of the B-N rings, B-N-C bonds and the influence of temperature on the crystallization of h-BNC to reveal the mechanism of the structure development of BNC precursor to ceramics. The implementation of the project will solve the formation problem of carbon substrate composites and enhance the performance of high temperature resistance establish the foundation for further research of BNC performance and actual application in some extent.