新型含氟端羟基聚合物结构设计与交联网络调控研究

Binder is a kind of matrix material for curing network system, which is also a fuel with corresponding energy in PBX (Polymer Bonded Explosive). Its energy characteristics and curing network structure determine the performance of PBX. We have recently observed that difluoroamino binders are ideal solid propellant binders and are promising candidates for cast PBX explosives, and their molecular structural parameters and the regulation of crosslinking networks and construction mode are the key scientific issues to be solved. This project is intended to copolymerize stable geminal difluoroamino compound and azide tetrahydrofuran to form a series of fluorine-containing and hydroxyl-terminated polymer binders with high energy, flexible molecular chain and good compatibility. By introducing hyperbranched polyols polymer and their terminal modifications as curing network regulators, a cross-linked network structure with excellent mechanical properties will be built. The rheology of the energy-containing binder system and curing reaction kinetics equation will be explored. The energy characteristics (theoretical specific impulse, enthalpy of formation, detonation velocity and explosion pressure) of difluoroamino polymer and their structure relationship will be revealed and established. A polymer structure model suitable for PBX will be established. The results of this study can not only enrich the basic knowledge of fluoropolymer, but also provide a scientific basis for the application of difluoroamino compounds to PBX explosive system.

粘合剂是固化网络体系构建的基体材料，在PBX（聚合物粘结炸药）中也是具备相应能量的燃料，其能量特征、固化网络结构决定了PBX炸药性能的高低。我们新近观察到：二氟氨基粘合剂是较为理想的固体推进剂粘合剂，其使用在浇注型PBX炸药中必将具备很好的应用前景，而其分子结构参数及交联网络的调控与构建模式则是需要解决的关键科学问题。本项目拟以稳定型的偕二氟氨基化合物和叠氮四氢呋喃共聚，形成一系列能量高、分子链柔顺、填料相容性好的含氟端羟基聚合物粘合剂；通过引入超支化聚合物多元醇及其端基改性物作为固化网络调节剂，构筑力学性能优异的交联网络结构；探讨含能粘合剂体系流变学规律及固化反应动力学方程；揭示二氟氨基聚合物能量特征（理论比冲、生成焓、爆速、爆压）及其构效关系；建立适合于PBX的聚合物结构模型。本研究成果既能丰富含氟聚合物基础知识，也能为二氟氨基化合物应用于PBX炸药体系提供科学依据。

聚合物粘合剂是固化网络体系构建的基体材料，其性质的优劣在很大程度上决定了PBX炸药性能的高低。端羟基含氟聚醚使用在浇注型PBX炸药中具备很好的应用前景。但其分子结构参数及交联网络的调控，则是需要解决的关键科学问题。.本项目分别探讨了端羟基氟氨聚醚含能粘结剂和端羟基含氟聚醚粘结剂作为PBX炸药组分的合成方法、固化网络结构及其应用性能，具体研究结果如下：.1. 端羟基氟氨聚醚含能粘结剂：通过羰基加成反应，得到偕二氟氨基酯类加成化合物，然后通过水解，得到偕二氟氨基醇类化合物，再将环氧氯丙烷与之缩合，制得稳定性好的偕二氟氨基单体化合物，最后通过开环聚合，获得端羟基二氟氨基聚醚（PBFGT），该含能粘结剂的NF2%高达35.1%，密度为1.24 g/cm3，玻璃化温度-55℃，具备高能高分解温度及低玻璃化温度特征。.2. 端羟基含氟聚醚粘结剂：通过环氧化合物与氟醇反应得到产率高、价格低廉的含氟环氧单体FPO。然后将其与PTMG阳离子开环聚合，制备了端羟基含氟三嵌段共聚物PFPO-PTMG-PFPO。实验发现其密度高、玻璃转化温度（Tg）低（-64.1-51.8℃）；热稳定性好（最大失重温度365.0℃左右）；与燃料组分、氧化剂组分间的相容性好、安全性高；流变性满足浇注工艺。此外，制备的超支化多元醇HPG作为PFPO-PTMG-PFPO固化体系的交联剂，发现形成的含氟聚氨酯胶片的Tg下降3.1℃，胶片的断裂应力（TS=1.23 MPa）、断裂伸长率（Eb=107.24%），均高于空白组（TS=074 MPa，Eb=57.78%），展现出更加良好的机械性能。应用试验表明浇注PBX的力学性能较好，安全性高。.本研究通过设计合成新型的含氟聚醚粘结剂，通过引入超支化多元醇作为交联剂进行网络的调控得到性能优异的含氟粘结剂体系，为PBX的粘结剂材料及网络构建提供一种新的可能。.