Enhanced Interfacial and Mechanical Properties of PBX Composites via Surface Modification on Energetic Crystals

Abstract

The mechanical properties of composites are highly dependent on the interfacial interaction. In the present work, inspired by marine mussel, the adhesion between energetic crystals of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and polymer binders was improved. Three types of linear polymeric agents of glycidyl azide polymer (GAP), polyethylene glycol (PEG), and polytetramethylene ether glycol (PTMEG) were grafted onto TATB particles bridged through polydopamine (PDA) films. SEM images showed that 5% grafting contents could evidently form roughness shells on the surface. With a reinforcement at the interface produced by grafting shells, the mechanical properties of polymer-bonded explosives (PBXs) exhibited outstanding mechanical performance, especially for the PTMEG-grafting sample. Examined by the contact-angle test, the PTMEG-grafting sample possessed a value of polar component similar to that of fluoropolymer, leading to an excellent wettability of the two phases. Additionally, different contents of PTMEG were grafted to reveal that the mechanical properties could be improved even with content as little as 0.5 wt.% PTMEG. These results might highlight a correlation between interfacial interaction and macroscopic properties for mechanically energetic composites, while providing a versatile route of grafting on highly loaded composites.

A Review of Polysiloxanes in Terms of Their Application in Explosives

“…The authors of [ 47 ] conducted similar tests on the functionalization of explosive crystals’ surfaces using polydopamine (PDA). The functional groups derived from polydopamine were then used to make grafted copolymers with other polymers: poly(glycidyl azide) (GAP), poly(ethylene glycol) (PEG) and polytetramethylene ether glycol (PTMEG).…”

The Art of Framework Construction: Core–Shell Structured Micro-Energetic Materials

“…It has been demonstrated that PDA and HBP shells have synergism in enhanced mechanical properties and improved interfacial adhesion. Another similar work was reported by Zeng et al [ 58 ] in which the PDA layer served as interfacial layer of TATB particles with three polymer binders: glycidyl azide polymer (GAP), polyethylene glycol (PEG) and polytetramethylene ether glycol (PTMEG), leading to outstanding mechanical properties and good compatibility between the composites and binders in PBXs.…”

“…TATB is a moderately powerful, thermally stable and insensitive explosive [ 15 , 107 , 108 , 109 ]. TATB crystals consist of graphite-like sheets with considerable intermolecular interactions between layers [ 34 , 58 ]. However, TATB crystals suffer from large deformation when exposed to the thermal physical environment due to their unique structure, which restricts long-term storage and transport.…”

“…A further study was reported by taking the PDA-modified surface as a secondary reaction platform for the grafting of three polymer binders: GAP, PEG, and PTMEG [ 58 ]. The composites demonstrated superior mechanical performance over virgin TATB, especially for the PTMEG-grafting CSE ( Figure 8 ).…”

Enhanced Creep Resistance and Mechanical Properties for CL‐20 and FOX‐7 based PBXs by Crystal Surface Modification

“…After that, TATB was coated with PDA under different polymerization time, and the mechanical strength was increased obviously due to strong wettability between TATB@PDA and F2314 adhesive [14]. Furthermore, based on the large amount of hydroxyl and amino active groups of PDA, which act as secondary active sites, linear and hyperbrached polymers were grafted onto the surface of TATB [15–16]. Combined with chemical bonding of PDA and introduced “interlocking block” effects of polymers, the interfacial interaction of TATB based PBXs was evidently reinforced.…”