Search Results (2)

Epoxy resin (EP) is an indispensable packaging material for batteries. Excellent thermal and flame-retardant properties of EP can ensure the safety performance of batteries. To solve the low-efficiency flame retardant of EP, nickel phenyl phosphate (NiPP) was synthesized and its surface was modified by polymerization of dopamine (PDA). [3-(hydroxy-phenyl-methylidene) imimine] triazole (DTA) was synthesized using 9,10-dihydro-9-oxygen-10-phosphophene-10-oxide (DOPO), 3-amino-1,2,4-triazole and p-hydroxybenzaldehyde. The hybrid flame retardance NiPP@PDA@DTA was further synthesized by self-assembly between the negative charge on the surface of DTA and the positive charge on the surface of modified NiPP@PDA. Then, NiPP@PDA@DTA was added to EP to prepare EP/NiPP@PDA@DTA composites. The results showed that the incorporation of NiPP@PDA@DTA promoted the residual yield at high temperatures. Furthermore, EP composites showed excellent flame retardancy when NiPP@PDA@DTA was added. The EP/4 wt% NiPP@PDA@DTA composites can reach UL-94 V0 grade with a limit oxygen index (LOI) of 33.7%. While the heat release rate (HRR), total release rate (THR), CO₂ production (CO₂P) and total smoke release (TSR) of EP/4 wt% NiPP@PDA@DTA composites decreased by 16.9%, 30.8%, 16.9% and 27.7% compared with those of EP. These improvements are mainly due to the excellent catalytic carbonization performance of Ni metal and P compounds. The azazole and phosphaphenanthrene groups have the effects of dilution quenching in the gas phase and cross-linking network blocking, as well as enhanced blowing-out effects. Full article

It is an arduous and meaningful challenge to design and develop new energetic materials with lower sensitivity and higher energy. How to skillfully combine the characteristics of low sensitivity and high energy is the key problem in designing new insensitive high-energy materials. Taking a triazole ring as a framework, a strategy of N-oxide derivatives containing isomerized nitro and amino groups was proposed to answer this question. Based on this strategy, some 1,2,4-triazole N-oxide derivatives (NATNOs) were designed and explored. The electronic structure calculation showed that the stable existence of these triazole derivatives was due to the intramolecular hydrogen bond and other interactions. The impact sensitivity and the dissociation enthalpy of trigger bonds directly indicated that some compounds could exist stably. The crystal densities of all NATNOs were larger than 1.80 g/cm³, which met the requirement of high-energetic materials for crystal density. Some NATNOs (9748 m/s for NATNO, 9841 m/s for NATNO-1, 9818 m/s for NATNO-2, 9906 m/s for NATNO-3, and 9592 m/s for NATNO-4) were potential high detonation velocity energy materials. These study results not only indicate that the NATNOs have relatively stable properties and excellent detonation properties but also prove that the strategy of nitro amino position isomerization coupled with N-oxide is an effective means to develop new energetic materials. Full article