三维石墨烯/阻燃聚碳酸酯复合材料用于民用飞机减重材料的研究

Based on its virtues in low density, high toughness, excellent thermal insulation, the application of low-density flame-retardant polycarbonate micro-foams in cabin of airplane is meaningful for flight safety and energy conservation as well as greenhouse gas reduction. In this project, we plan to synthesize and characterize phosphorus containing polycarbonate ionomers (PCi) through esterification and condensation. Effects of phosphorus concentration on the micro-phase structure, melt strength and flame retardance of PCi will explored. To improve the melt strength and foaming capability, three-dimensional graphene (GSs) with high specific surface area and adsorption is compounded with PCi to fabricate GSs/PCi composites by chaotic mixing screw. The interaction mechanism of GSs and Pci will be investigated carefully, as well as the evolution of multi-phase structure (PCi amorphous zone -GSs-PCi cluster region). After obtaining the fundamental data for the structure and properties of the composites, we will finally prepare GSs/PCi composite micro-foams through supercritical carbon dioxide foaming technology. One of our objection is illuminate the micro-foam mechanism of GSs/PCi, including the adsorption- dissolution of CO2, heterogeneous nucleation ability and the process of bubbles growth. Furthermore, how the ionization, introduction of GSs into PC and sc-CO2 affect the crystallization behavior of PCi will be demonstrated. We will also investigate the effect of ionomeric unit contents and GSs loadings on the morphology, mechanical properties, flame-retardancy, and heat-insulating properties of GSs/PCi micro-foam. Effect of heat aging and ultraviolet radiation on the structure and properties of GSs/PCi micro-foam will survey to evate its civil aviation application. Based on these investigations, we hope to found the relationship in foaming technology-foaming microstructure-material properties, which will enrich the theory for understanding the structure and properties of micro-foam material. Besides, it is hopefully to get a useful material with practical application in airplane to contribute to green and safe flight. Meanwhile, we will promote the development of theory and technology of PC foam process by this research.

微孔泡沫塑料具有质轻和增韧等优点，用于机舱塑料件将促进民航节能减排。项目开拓一种用于民航机舱减重的阻燃石墨烯/聚碳酸酯离聚物(PCi)微孔泡沫制备新方法。以酯交换-缩聚法制备含磷PCi，探究磷离子浓度对PCi微相结构、熔体强度和阻燃性能的影响规律。基于三维石墨烯（GSs）高吸附力和比表面积等优点，采用差动双螺杆制备高性能GSs/PCi复合材料，探索GSs对PCi微相结构和多相界面的作用机制，阐明PCi无定形区-GSs-PCi离子簇区多相结构演变机理。以超临界CO2发泡技术制备GSs/PCi微孔泡沫，阐明CO2吸附-溶解和异相成核等微孔发泡机理。系统研究GSs/PCi微孔泡沫材料的结构与性能及其热老化和紫外辐射后的变化趋势，并建立结构-泡孔形态-性能作用关系，为制备民航飞机用新型阻燃PC微孔泡沫材料提供理论依据。研究成果将为绿色、安全民航做贡献，促进微孔泡沫制备理论和成型新技术的发展和应用。

微孔泡沫塑料具有质轻和增韧等优点，用于机舱塑料件将促进民航节能减排。保证飞行安全的前提下，尽量降低飞机重量，一直是航空科技领域的前沿课题。项目提出开拓一种用于民航机舱减重的聚碳酸酯离聚物(PC)复合材料微孔泡沫制备新方法。分别以酯交换-缩聚法和扩链反应制备含磷PCI、PBSI-K和含氨基离子的PBSUI，探究磷离子和离子种类浓度对PCI和PBSI微相结构、熔体强度和阻燃性能的影响机理。通过调控离子浓度，可以将聚酯的剪切黏度提高103以上，并且对其结晶性能具有异相成核作用，实现了在磷离子浓度仅为1%时，突破性的所得具有超大球晶的形态和高热导率（315 mW/m.k）的PBSI-K，丰富和发展了离子聚合物的新的结晶和热学特征。进一步以超临界CO2发泡技术制备PCI，PBSI-K和PBSUI微孔泡沫，获取具有高取向泡孔形态的微孔泡沫塑料（泡孔直径小于5.0um, 泡孔密度达5.28×1010 cells/cm3），同时具有高韧性和高压缩强度（压缩五次后保持为3.5 MPa，为纯PBS泡沫塑料的7倍以上）。通过调控离子单体的结构，包括获得闭孔率达98%PBSI-K微孔泡沫，其泡孔与泄压方向高度取向，并且实现对PBSI微孔泡沫塑料导热和隔热性能的调节，获得导热率高达315 mW/m.k, 对比纯PBS泡沫，该数值提高了9倍。基于有机多孔材料（AMOP）高吸附力和比表面积等优点，采用差动双螺杆制备高性能AMOP/PC复合材料，实现具有界面良好相容性的AMOP/PC复合材料。以超临界CO2发泡技术制备AMOP/PC微孔泡沫，其泡孔直径仅为2.5 um, 泡孔密度达到7.8×1010，阐明这种结构下的CO2吸附-溶解和异相成核等微孔发泡机理。首次报道AMOP/PC微孔泡沫形成具有珊瑚礁结构特征，其压缩强度、缺口冲击强度高达9.0 KJ/M2和23.2MPa,与纯PC微孔泡沫相比，分别提高了3.2倍和1.2倍以上，实现了具有高性能阻燃PC微孔泡沫塑料的轻量化目的。项目经过系统研究，完整建立结构-泡孔形态-性能作用关系，为制备民航飞机用新型阻燃PC微孔泡沫材料提供理论依据，促进微孔泡沫制备理论和成型新技术的发展和应用。