Rheological Properties Of Double-base Propellant Containing RDX Or EC

The double-layer variable burning rate propellant has good properties of progressive combustion by controlling the burning rate of the inner and outer layers.However,with the increase of solid content,the rheological properties of the formula with solid filler will change greatly,which directly affects the selection of propellant manufacturing process conditions and the control of product quality.In order to study the rheological properties of propellant,on the basis of double-base propellant,the double-base propellant containing solid filler was prepared by adding high-energy solid filler RDX or polymer flame retardant EC.Using the rheological test method,rotational rheometer is used to study of the rheological properties of double-base propellant containing RDX or EC,and the factors affecting the rheological properties were analyzed.The main research contents are as follows:(1)The stress shear test of double-base propellant containing RDX or EC shows that the double-base propellant with different RDX or EC contents has obvious shear thinning behavior,which is a typical pseudoplastic fluid;The linear viscoelastic region of RDX or EC double-base propellant was determined by dynamic strain scanning.(2)The effect of mass fraction of solid filler on the rheological properties of double-base propellant material was studied.The results of dynamic frequency scanning test showed that the composite viscosity increased with the increase of solid content of double-base propellant material at the same shear rate;Under the same strain condition,the storage modulus of the material also increases with the increase of solid content;Zero shear viscosity?₀ of material also increased significantly with the increase of solid content;At a certain temperature,the viscous flow activation energy E_?of double-base propellant decreases with the increase of solid content.(3)The rheological properties of double-base propellant material from low to high temperature were studied.The composite viscosity of double-base propellant material containing RDX or EC decreased rapidly with the increase of temperature;The dynamic frequency scanning experiment shows that the composite viscosity of the material decreases exponentially with the increase of angular frequency;The increase of material solvent ratio can also reduce the composite viscosity of double-base propellant.(4)Through the 3ITT,it was found that the double-base propellant material has obvious thixotropy.After shearing,the material structure can be restored after a certain period of time,the increase in solid content will increase the thixotropic recovery rate of the system.