Abstract: In order to study the solubility of SC-CO₂ in double-base propellant, the dissolution and diffusion coefficients of SC-CO₂ in oblate spherical propellants with different arc thicknesses are investigated by the static method and the Fick diffusion law, and the effect of co-solvent on the amount of dissolution and diffusion coefficient is studied. The results show that the dissolved amount of SC-CO₂ in the double-base oblate spherical propellant increases with the increase in saturation time and is stabilized after 8 h, reaching 16%. It increases with the increase in saturation pressure. However, the dissolved amount of SC-CO₂ decreases with the increase in saturation temperature, and the dissolved amount is higher at 40 ℃. The addition of co-solvent has a positive effect on the increase in dissolved amount of SC-CO₂, and the dissolved amount is increased to 22.6%. The thickness of oblate spherical propellants has no effect on the saturated dissolved amount of SC-CO₂. The desorption diffusion coefficient under ambient conditions is much larger than the adsorption coefficient under supercritical conditions. The saturated dissolved amount of SC-CO₂ reaches 16% without adding co-solvent. After adding co-solvent, the saturated dissolved amount of SC-CO₂ reaches at least 22.6%, which is increased by 41.3%. The dissolution of SC-CO₂ in oblate spherical propellants can be increased effectively by adjusting the process parameters and adding the co-solvents. Key

Key words: supercriticalcarbondioxide, double-baseoblatesphericalpropellant, co-solvent, solubility, diffusioncoefficient