燃烧调节剂ZnO对PET推进剂流变性能的影响

Effect of combustion regulator ZnO on rheological behavior of PET propellant

综合使用高级扩展流变仪、旋转粘度计研究了燃烧调节剂ZnO对端羟基环氧乙烷-四氢呋喃共聚醚(PET)推进剂药浆流变性能的影响,并确定了PET推进剂中ZnO含量及制备温度的控制条件。研究表明,加入ZnO后,PET推进剂药浆的流变性能(粘度、屈服值)均明显增大,且其增值与ZnO含量呈正相关性。ZnO会催化推进剂药浆中PET与固化剂(TDI、LM-100)的化学反应,导致推进剂流变性能对温度的敏感性升高,易引起药浆在混合过程中温度急剧升高。当保持药浆温度低于50℃时,推进剂固化反应速率较为稳定,当温度高于超过该临界温度时,固化反应速率快速升高,并造成PET推进剂流变性能快速恶化。为保证推进剂药浆流变性能满足工艺要求,PET推进剂配方中燃烧调节剂ZnO含量不宜超过0.15%,推进剂制备过程中温度应低于50℃。

The influence of zinc oxide(ZnO)combustion regulator on rheological properties of PET propellant slurry was stud⁃ied by using advanced rheometric expansion system(ARES)and rotational viscometer.The content of ZnO and suitable preparation temperature of PET propellant were confirmed.The results show that the rheological properties(viscosity,yield)of PET propellant slurry are improved significantly after adding ZnO,and the values are positively correlated with the content of ZnO.ZnO can cata⁃lyze the reaction of PET with curingagents(TDI and LM⁃100),rnaking sensitivity on rheological properties of propellant to tempera⁃ture increase,which is easy to cause in the rapid rise of slurry temperature during the mixing process.When the temperature of slur⁃ry is kept below 50℃,the curing reaction rate of the propellant is relativoly stable.However,once the temperature is higher than the critical temperature,the curing reaction rate increasesrapisly and the rheological property of PET propellant deteriorates rapidly.In order to ensure the rheological property of propellant slurry to meet the process requirements,the content of combustion regulator in PET propellant should not exceed 0.15%,and the preparation temperature should be lower than 50℃.