一种改性HTPB固体推进剂的流变特性及其3D打印成型

Rheological Properties and 3D Printing of a Modified-HTPB Solid Propellant

快速发展的增材制造技术为固体推进剂传统浇注成型的柔性化、适应性差等问的解决题提供了有效途径。传统热固性固体推进剂的流平性好,无法逐层沉积成型。因而,为实现热固性固体推进剂的3D打印成型,本研究对其液相组分进行了改性,通过添加少量定型助剂共混改性端羟基聚丁二烯(HTPB),制备得到改性HTPB固体推进剂,并对其的流变特性进行了研究。结果表明,共混改性使黏合剂黏度、表观黏流活化能升高;改性HTPB固体推进剂流变特性符合Herschel‑Bulkley方程,且流动性随温度升高而提高;同时,改性HTPB固体推进剂在室温下具有较高储能模量(>104 Pa)以及较小的损耗角正切(ω<10 rad·s^(-1),G″/G'<0.5),整体不呈现流动性,且少量定型助剂对推进剂的热分解行为没有产生显著影响,实现了改性HTPB固体推进剂的3D打印成型。

The rapid development of additive manufacturing technology provides an effective way for the flexibility and adaptability of traditional solid propellant casting molding,however,to meet the requirements of the casting,the thermosetting solid propellants with good fluidity could not deposite layer by layer.In order to realize the additive manufacturing,the hydroxyl‑terminated polybutadiene(HTPB)was modified by adding a small amount of styling aids.The rheological properties of the modified‑HTPB and slurry made by using the modified‑HTPB were studied.The rheological curve test results show that apparent viscosity and viscous flow activation energy of the modified‑HTPB increase significantly with the decrease of temperature.The rheological property of the modified‑HTPB solid propellant slurry is consistent with Herschel‑Bulkley equation,and the fluidity of modified‑HTPB solid propellant slurry increases with the increment of temperature.Besides,the slurry possesses high storage modulus(G'>10^(4) Pa)and small loss tangent(ω<10 rad·s^(-1),G″/G'<0.5)at ambient temperature,showing a low fluidity.A small amount of styling aids has little effect on the thermal decomposition behavior of the propellant,which promotes the 3D printing of the modified‑HTPB solid propellant.