In this study, epoxy prepolymer (EC 157) and pentaerythritol tetrakis (3-mercaptopropionate) (PETMP) as hardener were encapsulated separately in polymethyl methacrylate (PMMA) shells through an internal phase separation method. Chemical structures, morphologies, and thermal properties of healing agent micro/nanocapsules were characterized by Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and thermal gravimetric analysis (TGA) respectively. The effects of encapsulation processing conditions such as mechanical mixing rate, ultrasonication, emulsifier type, and co-emulsifier concentration on encapsulation yield, capsule mean diameter and core content were studied using the Taguchi experimental design approach. The results indicated that the main significant factors affecting the yield of encapsulation are emulsifier type and ultrasonication. The most important factors which affect the mean diameter of capsules are emulsifier type and mechanical mixing rate. The core content was influenced by ultrasonication and mechanical mixing rate. The relative optimum condition of encapsulation was also determined using overall evaluation criteria.

The M06‐2X/6‐311G(d,p) and B3LYP/6‐311G(d,p) density functional methods and electrostatic potential analysis were used for calculation of enthalpy of sublimation, crystal density and enthalpy of formation of some thermally stable explosives in the gas and solid phases. These data were used for prediction of their detonation properties including heat of detonation, detonation pressure, detonation velocity, detonation temperature, electric spark sensitivity, impact sensitivity and deflagration temperature using appropriate methods. The range of different properties for these compounds are: crystal density 1.51–2.01 g cm−3, enthalpy of sublimation 346.4–424.7 kJ mol−1, the solid phase enthalpy of formation 500.4–860.6 kJ mol−1, heat of detonation 13.64–17.57 kJ g−1, detonation pressure 33.0–37.0 GPa, detonation velocity 8.5–9.5 km s−1, detonation temperature 5488–6234 K, electric spark sensitivity 7.89–9.47 J, impact sensitivity 21–38 J, deflagration temperature 560–586 K and power [%TNT] 207–276. The results show that two novel energetic compounds N,N′‐(diazene‐1,2‐diylbis(2,3,5,6‐tetranitro‐4,1‐phenylene))bis(5‐nitro‐4H‐1,2,4‐triazol‐3‐amine) (DDTNPNT3A) and 1,1′‐(diazene‐1,2‐diylbis(2,3,5,6‐tetranitro‐4,1‐phenylene))bis(3‐nitro‐1H‐1,2,4‐triazol‐5‐amine) (DDTNPNT5A) can be introduced as thermally explosives with high detonation performance.

In this article, density functional theory (DFT) and electrostatic potential (ESP) analysis are used to predict enthalpy of sublimation, crystal density and enthalpy of formation for some isomers of 20 new derivatives of nitroazacubane as new high performance energetic compounds. These data are used to predict detonation and physicothermal properties of the mentioned compounds, including heat, pressure, velocity and temperature of detonation as well as deflagration temperature, melting point and entropy of fusion through appropriate theoretical methods. The predicted properties are compared with octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) as one of well‐known high performance energetic compounds. Detonation performance of nitroazacubane compounds are surprisingly much higher than HMX, which confirm that they can be introduced as novel high performance energetic compounds.

The performance of jet fuel depends on the density (ρ), condensed phase heat of formation (▵fH°(c)), and specific impulse (ISP). Exo‐tricyclo[5.2.1.0(2,6)]decane (C10H16) or JP‐10 is now used as a suitable synthetic liquid jet fuel because it has the approximated values of ρ=1.1 g cm−3 and ▵fH°(c)=− 123 kJ mol−1 and a broad range between the melting and boiling points, i.e. Tbp–Tmp=196.2 K. This work introduces a suitable pathway for calculation of the values of ρ, ▵fH°(c), and ISP of 13 well‐known isomers of JP‐10 and a series of saturated polycyclic hydrocarbons with general formula of CnHn′ (5≤n≤12) in order to specify high performance jet fuels. Although 13 compounds have larger values of ISP*ρ than JP‐10, only two compounds, tetraspiro[2.0.0.0.2.1.1.1]undecane and tetracyclo[3.2.0.0(2,7).0(4,6)]heptane, are suitable as jet fuels.

No abstract