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The rheological behavior of propellant slurries is crucial for ensuring the feasibility of the 3D printing process, controlling print quality, regulating performance, and simulating predictions. However, there have been relatively few prior studies on the rheological properties of composite solid propellant slurries at low temperatures, which hinders the application of 3D printing propellant technology under extreme temperature conditions. In addition, the use of 3D printing technology to manufacture propellants at low temperatures is advantageous for improving safety. This paper investigates the rheological properties of monodisperse systems with aluminum powder as a solid filler and end-hydroxy polybutadiene (HTPB) as the dispersed phase at low temperatures (−15∼10 °C). It explores the effects of solid content, temperature, and particle size on their rheological properties. Results show that the viscosity of the system in the range of −15∼10 °C increases exponentially with the decrease in temperature, and the viscosity at −15 °C increases by 616.90 % compared with that at 10 °C when the volume fraction (φ) of Al-1 is 35.8 %; the larger size of the particles the larger the viscosity is when the temperature and φ are the same, which is interpretes in terms of interfacial properties between the systems. The low-temperature correction factor is introduced into the Einstein-Roscoe equation to obtain the modified viscosity-volume fraction equation, and the correction factor is 0.0173, as evidenced by its excellent agreement with the experimental data.

Energetic materials are the energy materials used by weaponry to accomplish launch, propulsion, and destruction. However, during manufacture, storage and use, they may be damaged and form microcracks when subjected to external stimuli such as temperature, humidity and impact, which ultimately lead to changes in material properties. Self-healing materials can repair the damage through physical or chemical processes, restoring their properties and extending their service life. This paper reviews the classification of self-healing polymer materials, principles underlying technologies for room-temperature self-healing polymer materials, and the applications of these technologies in energetic materials. Furthermore, this study proposes several key directions for future research on the technologies and their applications in energetic materials.

In the title molecule, C26H17N3O2, both indole ring systems are essentially planar, with maximum deviations of 0.019 (2) and 0.033 (1) Å for the N atoms, and form dihedral angles of 34.40 (9) and 45.06 (8)° with the essentially planar pyrrole ring [maximum deviation = 0.020 (2) Å]. The dihedral angle between the two indole ring systems is 58.78 (6)°. In the crystal, molecules are connected by pairs of N—H...O hydrogen bonds, forming inversion dimers and generating R22(8) rings. Weak π–π stacking interactions, with a centroid–centroid distance of 3.983 (2) Å, are also observed.

A kind of liner suitable for HTPE propellant was developed by constructing HTPE and HTPB blend adhesive system. The effects of different solid fillers and crosslinker on the mechanical properties, adhesive properties, and ablation resestance and migration resistance of the liner were investigated. The surface mophology of the liner was observed by SEM. The results show that when the blending ratio of HTPE and HTPB is 1:5, 7 % molecular sieves, 7 % silica and chain extender TMP were added respectively, the tensile strength of the liner reaches 2.30 MPa at 20 °C, and the fracture elongation is 203 %, the linear ablation rate is 0.59 mm.s-1, the pull􀀎off strength of the shell/insulator/liner/propellant reaches 0.90 MPa, and the mobility of nitrate ester plasticizer is 4.3 %. [ABSTRACT FROM AUTHOR]