耐热聚合物多孔材料的物理、化学重构

As for the application of porous polymer materials in military hardware, national defense and aerospace, the heat-resistant and heat-insulation polyurethane (PU) based porous foam will be developed. Through the design of PU molecular system, the heat-resistant/ fire retardant structure units will be introduced to the PU molecules and inorganic reinforced particles will be composited with PU, and the PU with gradient heat-resistant sequence structure and reinforcing structure will be prepared. Furthermore, along with the conception of polymer functional gradient materials (PGM), the composition/structure gradient will be designed for PU foam. The heat-resistant PU prepolymer will be mixed with foaming/crosslinking system and layer pouring foaming will be conducted, and PU foam with the controllable composition gradient will be prepared by adjusting the heat-resistant sequence structure and reinforcement structure of each layer. By adjusting the component and dosage of foaming/crosslinking system and external temperature field, and adding inorganic nano-particle nucleation agent, the pore structure parameters of PU foam can be controlled, and the controllable pore structure gradient distribution will be achieved. The synergistic mechanism of composition gradient and structure gradient will be studied so as to realize the mechanical gradient, heat-resistance gradient and heat-insulation gradient. The effect of composition and structure gradient on the performances of PU will be studied and the new method of the physical/chemical reconstruction of PU porous materials with high performances will be established.

本项目针对聚合物多孔材料在武器装备、国防军工、航空航天领域的应用，研究发展耐高温隔热聚氨酯基多孔材料。拟从耐热/阻燃/增强聚氨酯分子体系设计着手，将耐热/阻燃结构基元引入聚氨酯分子链或与无机增强粒子复合，制备具有渐变耐热基元序列结构和增强结构的聚氨酯；进一步引入聚合物功能梯度材料（PGM）概念进行其组分/结构梯度化设计与构建，将耐热增强聚氨酯预聚体与发泡/交联体系混合进行逐层浇注发泡，调节各层耐热/阻燃基元序列结构及增强结构，制备具有可控组分梯度的聚氨酯发泡材料；通过调节聚氨酯发泡/交联体系的组成、用量及外部温度场、添加无机纳米粒子成核剂等方法，调控发泡材料泡孔结构参数，实现聚氨酯泡孔结构的可控梯度分布；研究组成梯度与结构梯度协同作用机制，实现材料的力学梯度、耐热/阻燃梯度、隔热梯度，揭示其组成、结构梯度化对其性能的影响规律，建立聚氨酯泡沫多孔材料物理、化学构建及高性能化新方法。

针对聚氨酯材料在武器装备、国防军工、航空航天等领域的应用需求，根据其分子中存在热不稳定基团、耐热性能较差，在高温下易发生软化、降解，力学性能衰减较快的问题，从耐热/阻燃/增强聚氨酯分子结构及复合体系设计着手，探索提高聚氨酯及其泡沫材料耐热稳定性的途径，将高热稳定的酰亚胺基、硅氧烷基或具有笼型结构的聚倍半硅氧烷有机/无机杂化粒子引入聚氨酯分子链，与高强度及具独特热稳定作用的石墨烯复合，通过对合成、制备方法的研究，获得了具有优异热力学稳定性及阻燃性的聚氨酯基泡沫多孔材料，所制备的 PUIF-POSS 纳米复合泡沫室温储能模量可达近600 MPa，200℃时的储能模量仍保持近200MPa，玻璃化转变温度高达305℃，阻燃等级达 V1级；同时研究制备了耐高温阻燃环氧树脂改性聚异氰脲酸酯泡沫多孔材料、聚醚酰亚胺基微孔复合泡沫材料，探索体系组成及制备工艺条件对泡沫材料的分子结构、泡孔结构、力学性能、热解行为和燃烧行为的影响规律。引入聚合物功能梯度材料的概念进行其组分/结构梯度化设计，通过在聚合物体系中引入磁性组分/外加磁场方法、施加温度梯度场/单向冰晶诱导自组装法及层层组装法等，研究制备了具有梯度结构的聚氨酯、聚酰亚胺多孔材料，以实现其泡孔结构及热稳定性等的可控梯度分布，建立耐热聚合物泡沫多孔材料物理、化学构建及高性能化新方法，为其在高温等苛刻环境的实际应用奠定坚实基础。