Preparation And Properties Of Gradient Microporous Oblate Spherical Propellants

In order to improve the internal ballistic performance of the oblate spherical propellant,the problem of reducing the surface burning is alleviated and its incremental combustion is realized.In this paper,the principle of microporous polymer was prepared by supercritical carbon dioxide（SC-CO₂）foaming,and the gradient microporous oblate spherical propellant with different arc thickness was prepared by step heating method.The surface repair process of ethyl acetate and poly-p-pentylene glycol adipate（NA）was proposed to solve the problem of too fast burning rate of the prepared samples.The effects of technological conditions on the physical structure and combustion properties of microporous oblate spherical propellant were investigated,and the stability of the preparation process of foamed samples was investigated.The effects of surface repair process conditions on the physical structure and internal ballistic performance of the repaired samples were studied,and the high temperature storage stability of the repaired samples was investigated.The solubility of SC-CO₂ in oblate spherical propellant was studied by gravimetric analysis.The results show that the arc thickness of the propellant has little effect on the saturated dissolution of SC-CO₂ in the oblate spherical propellant.it gradually decreases with the increase of saturation temperature.it gradually increases with the extension of saturation time,at 7 hours.The post-dissolution reaches equilibrium.it increases with increasing saturation pressure.the addition of a co-solvent contributes to an increase in the amount of dissolution.The results of electron microscopy showed that with the extension of desorption time and the increase of saturation temperature,the thickness of unfoamed skin layer of foamed samples increased gradually,and the cell distribution became more dense.With the increase of foaming temperature,the cell density decreased gradually.Small,the cell diameter gradually increases,while the thickness of the unfoamed skin gradually decreases.The surface of the surface repair sample is smoother and the thickness of the unfoamed skin layer is increased.The results of closed explosives show that with the prolongation of desorption time,the effect of foaming sample gradual increase gradually deteriorates.with the increase of foaming temperature,the overall combustion dynamic activity of the sample increases,and the gas generation rate increases.The overall combustion activity of the surface treated sample is greatly reduced,the combustion is more gradually increased,and the combustion increasing performance of the foamed sample is better improved.After the surface treatment sample is stored at high temperature,the ballistic performance remains stable and has certain application value.