Acceleration of the thermal degradation of PETN in the microdroplets flow reactor

Constructing Single- or Dual-Layer Biomass Composite Energetic Material through Self-Assembly of Biomass Polyphenol Structural Materials

High energy and high risk have always restricted the application of materials in the military and civilian fields. To achieve this goal, researchers have studied the structural characteristics and structure-activity relationship of biomass polyphenol material to obtain core-shell biomass polyphenol composite energetic materials through molecular and structural design. The interface structure has a significant impact on the safety performance and thermal stability of energetic materials. The unique advantages of natural biomass polyphenol chemistry (tannic acid and tea polyphenols) include the structural design and performance control of energetic materials. This paper provides a review of the preparation of core-shell biomass polyphenol energetic materials, which involve the use of polyphenols as the shell layer, surface modification layer, and intermediate layer to enhance intermolecular interactions. This approach aims to enhance the thermal stability and reduce the sensitivity. Furthermore, the paper offers suggestions for potential future research directions based on the findings.

Photolysis by UVA-Visible Light of TNT in Ethanolic, Aqueous-Ethanolic, and Aqueous Solutions According to Electrospray and Aerodynamic Thermal Breakup Droplet Ionization Mass Spectrometry

The mechanism of photolytic degradation of 2-4-6-trinitrotoluene (TNT) by UVA−visible light (>320 nm) in ethanolic, aqueous-ethanolic, and aqueous solutions was investigated by electrospray and aerodynamic thermal breakup droplet ionization mass-spectrometric analyses. For the photolysis, a DRK-120 mercury-quartz lamp was used. Products of the photolysis reaction were compared with known products of TNT transformation in the environment. Because the photochemistry of some compounds in alcohols (in contrast to aqueous solutions) features a transfer of electrons from the solvent to the light-excited compound, we believe that the efficiency of photolysis (polymerization) of TNT in ethanol and aqueous-ethanolic solutions is based on this mechanism.

Establishing the Interface Layer on the Pentaerythritol Tetranitrate Surface via In Situ Reaction

Pentaerythritol tetranitrate (PETN) was coated by tannic acid (TA), polydopamine (PDA), and melamine-formaldehyde (MF) resins via in situ reaction to prepare PETN@TA, PETN@PDA, and PETN@MF microcapsules for reducing sensitivity and enhancing thermal stability of PETN. The coating effects of TA, PDA, and MF shells on PETN surfaces are characterized by scanning electron microscopy and atomic force microscopy. The structures of PETN@TA, PETN@PDA, and PETN@MF microcapsules are characterized by X-ray photoelectron spectroscopy, X-ray diffraction, and Fourier-transform infrared spectra. The performances of PETN@TA, PETN@PDA, and PETN@MF microcapsules are characterized by differential scanning calorimetry, accelerating rate calorimetry, explosion point, vacuum deflation volume, and mechanical sensitivity. The study results show that TA, PDA, and MF shells can coat the PETN surface well. Compared with pure PETN, the explosion point has an increase while the vacuum deflation volume and mechanical sensitivity have a decrease for PETN@TA, PETN@PDA, and PETN@MF microcapsules, illustrating that the safeties of PETN@TA, PETN@PDA, and PETN@MF microcapsules are enhanced. In addition, the initial decomposition temperature (T₀) and peak decomposition temperature (T_p) of PETN@TA, PETN@PDA, and PETN@MF microcapsules have a slight increase, demonstrating that the thermal stabilities of PETN@TA, PETN@PDA, and PETN@MF microcapsules are better than that of pure PETN. The obtained method can provide some guidance for the desensitizing of other energetic materials with high sensitivities.