端羟基嵌段共聚醚的制备及其力学性能研究

Study on preparation of hydroxyl-terminated polyether binder and its mechanical property

作为一种固体推进剂粘合剂,端羟基聚醚(HTPE)因其优异的力学性能以及与含能材料的良好相容性得到广泛报道与应用,然而如何针对HTPE推进剂进行配方设计仍是一个难点.因此,本研究使用开环聚合的方式制备了一种三嵌段共聚醚PEG-PTHF-PEG,并将其与两种不同的常用含能增塑剂N-丁基-N-(2-硝基-羟甲基乙基)硝胺(BuNENA)、双(2,2-二硝基丙基)缩乙醛/双(2,2-二硝基丙基)缩甲醛(BDNPA/F)共同制备含能粘合体系.为验证所制备共聚醚能否与含能增塑剂配合使用,使用分子动力学模拟对两种体系的相容性和相互作用进行进一步分析.结果表明PEG-PTHF-PEG可与上述两种含能增塑剂配合使用,且PEG-PTHF-PEG/BuNENA体系的相容性和结合能优于PEG-PTHF-PEG/BDNPA/F体系,其中主要相互作用力为较强的氢键和范德华力.进一步,通过共聚醚和异氰酸酯在增塑剂存在下反应制备了两种粘合剂弹性体,并通过拉伸试验评估了其力学性能,结果表明所制备共聚醚有望在固体推进剂中得到进一步应用.

Hydroxyl-terminated polyether has been utilized as the propellant binder in recent years.However,how to prepare HTPE binder with proper formula is still a big challenge.Herein,in this paper,the PEG-b-PTHF-b-PEG copolymer was synthesized through ring-opening polymerization and utilized with energetic plasticizers N-butyl-N-(2-nitroxy-ethyl)nitramine(BuNENA)and bis(2,2-dinitropropyl)acetal/bis(2,2-dinitropropyl)formal(BDNPA/F)to prepare the HTPE binder.Importantly,molecular dynamic simulation was used to analyze the miscibility and the interaction mechanism between the synthesized PEG-PTHF-PEG and energetic plasticizers BuNENA and BDNPA/F.The simulation results indicated that the compatibility and binding energy of PEG-PTHF-PEG/BuNENA blends was a little better than that of PEG-PTHF-PEG/BDNPA/F blends.Moreover,hydrogen bonds and van der Waals force existed between synthesized PEG-PTHF-PEG and plasticizers through simulation results.To testify the simulation results above,PEG-PTHF-PEG based elastomers were prepared by the reaction of synthesized polymer and isocyanate in the presence of plasticizer,and its mechanical property was evaluated by tensile tests.The final result is in consistence with the simulation study.This research will show advantage in the design,as well as actual application of polymers.