耐500℃有机无机杂化聚酰亚胺树脂基复合材料研究

High temperature resistant metal-based and ceramic-based composites have been used in aeroengines because they have superior temperature resistance compared to fiber reinforced plastics. But fiber reinforced plastics can provide higher performance than metal-based and ceramic-based composites in their usable temperature range. We can greatly reduce the structural weight and increase the thrust-to-weight ratio of the engine if use the high-temperature resistant resin-based composite materials in the secondary heat-resistant parts of the engine.The heat resistance of existing polyimide resin is long-term around 400 degrees because their organic chemical bond structure. This limits the application of polyimide composites in the field of aero engines. We utilize carborane which have excellent heat resistance as inorganic component to hybridizes the organic polyimide resin in the molecular level, and utilizes the excellent heat resistance of carborane to raise the temperature resistance level of the polyimide resin-based composite material to 500 degrees. This can provides a wider range of choices for aero-engine secondary temperature-resistant materials from traditional metal-based over-performance to resin-based composites with superior performance.

在航空发动机领域，虽然耐高温金属基及陶瓷基复合材料相比聚合物基复合材料具有更加优异的耐温性能，但是树脂基复合材料在其可用温度范围内却能提供更高的比强度、比模量及更加优异的耐疲劳性能。在发动机次级耐热部件广泛使用耐高温树脂基复合材料，可大幅度降低发动机的结构重量，提高发动机的推重比。现有的有机聚酰亚胺树脂受有机化学键键能的限制其耐热性长期在400度左右徘徊，这限制了树脂基复合材料在航空发动机领域的应用。本项目计划利用具有优异耐热性的无机组元碳硼烷在分子层面上杂化有机聚酰亚胺树脂，利用碳硼烷优异的耐热性将聚酰亚胺树脂基复合材料的耐温等级提升至500度，为航空发动机次级耐温材料从传统金属基过度到性能更为优异的树脂基复合材料提供了更为广阔的选择范围。

本项目针对新一代航空发动机装备对耐500℃树脂基复合材料的需求，力求解决耐高温树脂基复合材料在400-500℃温度区间长时使用（≥100h）无材可用的问题，其难点在于树脂基体的有机结构及碳纤维自身均无法承受400℃以上长时高温。重点完成了有机无机杂化聚酰亚胺单体制备、有机无机杂化聚酰亚胺树脂制备、有机无机杂化聚酰亚胺预浸料制备、有机无机杂化聚酰亚胺复合材料成型工艺、有机无机杂化聚酰亚胺复合材料500℃长时老化及相应的典型结构验证件的制造考核等研究内容；突破了耐500℃有机无机杂化聚酰亚胺单体合成、有机无机杂化聚酰亚胺树脂合成、有机无机杂化聚酰亚胺预浸料制备及有机无机杂化聚酰亚胺复合材料成型等关键技术；研制了杂化二胺及二酐单体、杂化聚酰亚胺树脂、碳纤维预浸料、杂化聚酰亚胺树脂基复合材料。其中杂化树脂最低粘度可达7Pa.s、5%热分解温度达643℃、玻璃化转变温度≥600℃，AC741/碳纤维复合材料各项力学性能及500℃长时老化性能均达到可用状态，为耐500℃树脂基复合材料在航空发动机等航空航天领域的应用奠定了材料基础。