Molecular dynamics simulation on ε-CL-20 based PBXs with chain-extended poly(3,3-bis(azidomethyl)oxetane)

MD simulation was performed on ε-CL-20 and CL-20-based PBX systems(P1, P2, P3) to study their performances. P3 exhibits lower sensitivity and shows highest mechanical strength among PBX systems. ε-CL-20 based PBXs with 5% IPDI-CE shows higher detonation performance than pure HMX. [Display omitted] •CE-PBAMO with various isocyanates were used to construct ε-CL-20-based PBXs models.•IPDI-CE exhibits better compatibility with ε-CL-20(0 0 1) from MD simulations.•ε-CL-20 blended with IPDI-CE has lower sensitivity and higher mechanical strength.•ε-CL-20 blended with 5% IPDI-CE shows better detonation performance than pure HMX. Molecular dynamics (MD) method was performed on ε-CL-20 based PBXs, which were constructed by embedding different chain-extended poly(3,3-bis(azidomethyl)oxetane)(CE-PBAMO) with ε-CL-20(001) crystalline surface. The binding energy(Ebinding), maximum bond length (Lmax) of the N-NO2 trigger bond, cohesive energy density (CED) and mechanical properties of ε-CL-20 (P0) and PBX systems(P1, P2, P3) were calculated. The order of Ebinding is P3 > P1 > P2, implying that CE-PBAMO with isophorone diisocyanate (IPDI-CE) and ε-CL-20 have better compatibility. Lmax is found to be in the order of P0 > P2 > P1 > P3, which indicates that the addition of polymer binders lowers the sensitivity of the base explosive, and IPDI-CE minimized sensitivity of the base explosive. The order of CED is P0 > P3 > P1 > P2, demonstrating that polymer binders show same tendency in reducing the sensitivity of the base explosive with Lmax calculation. Moreover, mechanical property calculation results reveal that the tensile modulus (E), bulk modulus (K) and shear modulus (G) of pure ε-CL-20 are larger than ε-CL-20 based PBXs, while the values of Cauchy pressure (C12-C44) change a little and increase for ε-CL-20 based PBXs. The calculation of detonation performance shows that ε-CL-20 based PBXs with 5% IPDI-CE possess high power and lower sensitivity.