Study on the mechanical and burning properties of polytriazole crosslinked solid composite propellants

The traditional solid composite propellants with the terminal hydroxyl adhesive/isocyanate curing agent system are high water-sensitive, poorly compatible and stable with some novel solid additives such as ammonium dinitramide(ADN)and boron powders. These problems are expected to be solved by preparing the polytriazole cross-linked solid composite propellants using propargyl-terminated ethylene oxide-tetrahydrofuran copolymer(PTPET)as a adhesive and polyazide compound as an curing agent. The propellant samples were prepared containing different components: S1(common formula), S2(containing LBA-604), S3(containing ADN), S4(containing boron). The mechanical and burning properties of these samples were tested. The tensile stress and the broken strain are 0.60 MPa and 15%, 0.63 MPa and 31%, 0.40 MPa and 24%, 0.72 MPa and 124% at room temperature; 1.69 MPa and above 150%, 2.10 MPa and above 149%, 1.18 MPa and above 145%, 2.10 MPa and above 149% at -40°C; 0.47 MPa and 23%, 0.49 MPa and 21%, 0.32 MPa and 17%, 0.57 MPa and 84% at 60°C. The burning rate pressure exponents are 0.49, 0.52 and 0.38 for S2~S4 at 4~8 MPa. Under argon atmosphere, the explosion heat is 6669, 6695, 6350 and 7014kJ/kg for S1~S4 at pressure of 4 MPa. The burning rate-explosion heat formula is summed up.