电子封装材料用碳基助剂的导热阻燃协同机理研究

In the present project, a difunctional grapheme carbon-based aid synthesized by us is used to prepare epoxy electronic packaging material with good heat conduction and flame resistance, and meanwhile the synergistic mechanism was investigated. A reactive long-chain flame retardant containing P is grafted onto oxidized grapheme. Such long-chain structure is helpful to push the grapheme sheets, and exfoliate the conglomerated sheets to ahieve thin-layer dispersion. Moreover, the long-chains can extend into the resin matrix to improve the interfacial combination, thus decreasing interfacial phonon scattering and thermal resistance. The heat conductivity can be effectively enhanced. Taking the advantages of the synergistic and complementary effects of the two-dimensional grapheme sheets with high isolation property and the formed chemical chars (P catalyzes the resin into chars), the flame retardant efficiency can be improved: in the initial combustion stage, the grapheme sheets with high isolation effect (physical carbon), can hold back the diffusion of oxygen and the volatiles from degradation of the resin. With production of the chemical chars, they encapsulate the grapheme sheets to form dense and solid composite carbon layer, therefore, high efficient flame retradacne can be achieved. Additionally, the heat conducting and flame retarding action and mechanisms of the carbon-based aid is researched. The related data between thermal conductivity and flame retardance are real-time collected and analyzed. A mathematical model containing the expression factors of thermal conductivity and flame retardance is tried to be established. The corresponding results of the project is expected to overcome the existing limitation of adding flame retardants and thermal conductive agent in matrix respectively for preparation of flame retarded and heat conducting polymers, and also fill up the void concerning the heat-conducting and flame retarding synergistic theory. It can provide basic data and theoretical foundation for the application of the new carbon-based aid in defense and military packaging filed.

本项目拟建立以双功能型石墨烯碳基助剂来制备兼具优异阻燃和导热性能的环氧树脂电子封装材料新方法，深入研究碳基助剂导热-阻燃协同机理。通过长链含磷阻燃剂接枝氧化石墨烯，利用极性长链结构撑开石墨烯堆积片层并伸展到树脂基体实现薄层分散和界面增容，降低界面声子散射和热阻，有效提高导热性。利用高阻隔性石墨烯二维碳基结构与磷催化树脂形成化学炭层的协同互补效应提高阻燃效率：即燃烧初期由石墨烯片层（物理炭源）阻隔氧及热解小分子扩散，后期形成的化学炭层将石墨烯包裹形成致密坚固复合炭层，实现高效阻燃。研究碳基助剂导热及阻燃行为过程，对封装材料导热与阻燃相关性数据进行实时采集分析，尝试建立包含导热和阻燃相关表达因子的数学模型。相关研究成果有望克服现有阻燃导热聚合物材料制备需分别添加导热剂和阻燃剂的技术局限，填补导热-阻燃协同理论研究空白，为新型碳基助剂在国防军工封装材料领域应用提供基础数据及理论依据。

本项目建立了以双功能型石墨烯碳基助剂来制备兼具优异阻燃和导热性能的环氧树脂电子封装材料新方法，深入研究了碳基助剂导热-阻燃协同机理。通过长链含磷阻燃剂接枝氧化石墨烯，利用极性长链结构撑开石墨烯堆积片层并伸展到树脂基体实现薄层分散和界面增容，降低界面声子散射和热阻，有效提高导热性。利用高阻隔性石墨烯二维碳基结构与磷催化树脂形成化学炭层的协同互补效应提高阻燃效率：即燃烧初期由石墨烯片层（物理炭源）阻隔氧及热解小分子扩散，后期形成的化学炭层将石墨烯包裹形成致密坚固复合炭层，实现高效阻燃（4%碳基助剂即达到V0阻燃级别）。研究碳基助剂导热及阻燃行为过程，对封装材料导热与阻燃相关性数据进行了分析，建立了相关数学模型。相关研究成果填补了导热-阻燃协同理论研究空白，为新型碳基助剂在国防军工封装材料领域应用提供基础数据及理论依据，研制材料已在相关军工单位进行试用。