杂环聚芳醚腈-硅杂化隔热防护涂层的结构与性能研究

Thermal protection coating on resin matrix composites used in high speed vehicle is very crucial for regular running. Traditional inorganic coating has the poor adhesion to resin matrix composites, and their thermal expansion coefficients do not match with each other in the result that the coating usually drops off from the surface of resin matrix composites during flying. However, the bearing temperature of traditional organic coating does not meet the requirements for using at from 400 degree centigrade to 800 degree centigrade..In this project, starting from the molecular structure design, a kind of hybrid coating resin stemmed from poly(phthalazinone ether nitrile) (PPEN) and polysiloxane (PSQ) hybrid materials by blocking or grafting method. This resin will be blended with insulation fillers and additives to make a kind of heat-resistant thermal protection coating. In the coating film-forming process during drying, PSQ chain will migrate to the surface of the coating and enrich on the surface because of its low surface energy. Then with increasing the environment temperature, PSQ ceramic transition occurs under certain conditions on the surface and finally forms amorphous ceramic film. Meanwhile, PPEN will stick to the substrate, which will give the entire coating excellent adhesion and flexibility. The above coating will then form a heat-resistant insulation coating. The controllable preparation technique of PPEN/PSQ copolymer will be focused on researching. The coating composition and effects of coating process on its properties will be explored in details. Exploring the mechanism of surface PSQ ceramic will be carried out. The result of this research will enrich the theory of high performance heat-resistant coating and provide a super comprehensive performances thermal protection coating for high speed aircraft.

在高速飞行器的树脂基复合材料(RMC)表面涂覆热防护涂层是提高其使用温度等性能的最有效、最经济的手段。对于传统无机涂层与RMC的热膨胀系数不匹配，附着力差，使用中易脱落，而传统有机涂层的不能耐受400-800℃。本项目从分子设计出发，设计、合成含杂萘联苯聚芳醚腈(PPEN)和聚倍半硅氧烷(PSQ)杂化共聚物为成膜树脂，添加隔热填料和相关添加剂等，研究新型耐高温隔热涂料。在涂层干燥成膜过程中，表面能低的PSQ链段迁移富集于表层，随着温度升高，表层PSQ发生陶瓷化转变，形成无定形陶瓷膜；底层的PPEN与基底结合，赋予整个涂层优异的附着力和韧性，从而形成耐高温隔热涂层。系统研究PPEN/PSQ共聚物的可控制备技术；研究共聚物结构等对涂层性能的影响；研究涂料的组成和涂覆工艺对涂层性能的影响；探索表层PSQ陶瓷化机理。丰富耐高温高性能涂料制备理论，为高速飞行器提供一种综合性能优异的热防护涂料。

针对高速飞行器的树脂基复合材料(RMC)表面涂覆热防护涂层存在的问题，即传统无机涂层与RMC的热膨胀系数不匹配，附着力差，使用中易脱落，而传统有机涂层的不能耐受400-800℃等问题，研究一种树脂基复合材料表面的中温(即400-800℃)隔热防护涂层。主要研究内容是从分子设计出发，设计、合成含杂萘联苯聚芳醚和聚倍半硅氧烷杂化复合涂层，探讨其陶瓷化机理。根据研究目标，首先设计、合成了含端炔基或叠氮基的杂萘联苯聚芳醚砜酮或聚芳醚酮等聚合物，以及通过溶胶凝胶法合成陶瓷化先驱体含端叠氮基的聚硅氧烷聚合物（PSQ）PSQ优化其合成工艺，研究其固化反应；研究复合涂层的配方及其涂覆工艺，探讨有机硅树脂的陶瓷化产物及机理，通过选择和添加填料改善其尺寸稳定性，从而得到高温环境下烧蚀不开裂、不翘起、附着力好的复合涂层。研究结果表明，既耐高温又可溶解的杂萘联苯聚芳醚类树脂具有优异的耐热性能，其5%热失重高于500℃，与基体具有优异的附着力，表面的聚倍半硅氧烷（PSQ）与底漆杂萘联苯聚芳醚以化学键连接，随着温度升高，表层PSQ在一定条件下发生陶瓷化转变，最后形成陶瓷结构的耐高温抗氧化涂层。整个涂层在能耐受400℃、500℃、600℃、700℃单面加热10min、20min、30min，对基底起到了良好的热防护作用。本项目的研究对今后设计新型热防护涂层提高了一定的理论指导和技术支持。同时，本研究还延伸研究了准陶瓷化的复合材料用于导弹前部的雷达天线罩。