Improve The Mechanical Properties Of New High-energy Propellant

To improve the mechanical strength of New high-energy propellant, the formulation system nitrocellulose (NC), glycidyl azide polymer (GAP), nitroglycerine (NG) and RDX as the main component was studied on this proper. Through theoretical analysis, different Nitrated NC,different azide binder, different mix plasticizer, different curing agents and different curing techniques on the premise of same energy and burst temperature was designed and researched to improve the dispersion of polymer matrix system and the flexibility of polymer chain, coated RDX were studied to improve the interface compatibility between polymer matrix and RDX, adding reinforcing agents were also studied to prevent molecular chains from slippaging to enhance the mechanical properties of the new type of high-energy propellant. The results show that:(1)On the premise of same energy and burst temperature, increasing the nitrogen content of NC can help to reduce the amount of solid filler RDX and increase the amount of GAP and plasticizer to enhance the flexibility of polymer matrix network, improve the dispersion of polymer matrix system and reduce defect, so that the impact strength of the propellant(αk) increase, and the change of the combustion performance was little. With 13% nitrogen NC replacing 12.46% nitrogen NC, theαk of the propellant was increased 30%.(2) Compared to the NG plasticizer, the solubility parameter of the plasticizer mixed with DEGN and NG was close to the NC and GAP, which can help to improve the dispersion of the propellant, stretch the polymer matrix more freely and increase the flexibility of the polymer to enhance in the kneading, extrusion and other manufacturing processes, so the ak can be increased.(3)With Branched GAP replacing GAP, the dispersed degree of the system reduced, but B-GAP had a lower glass transition temperature, higher molecular weight,and more atoms for bearing stress, theαk was increased 25%;when using B-GAP for azide binder, the use of curing agent IPDI instead of N100 can prevent excessive cross-linking of B-GAP from being crisp, compared with GAP system, theαk of the B-GAP propellant cured with IPDI can be increased 32%.(4) Using macromolecule water-based polyurethane (WPU) as the coating agent of solid fillers RDX can help to reduce the surface energy of the RDX, improve the interfacial properties between filler and binder matrix, prevent the penetration of NG to RDX, thus, theαk,the compressive strengthσmax and compressibilityεmax are all significant improved. (5) Selecting the curing process that kneading the pre-cured GAP, the dispersed degree of the system reduced because the viscosity of the GAP was increased as a result of the larger molecular weight, but the curing level of GAP can be ensured effectively, and GAP or GAP and NC can form polyurethane or polyurethane-urea elastomers, the ak of the propellant can be increase 30%.