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

Chengcheng Zeng,Shijun Liu,Zhijian Yang,Yubin Li,Xu Zhao,Guansong He,Jianhu Zhang,Congmei Lin,Feiyan Gong

doi:10.3390/polym11081308

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.

Highlights

Polymer-bonded explosives (PBXs), including energetic materials (EMs) and polymer binders, attracted extensive attention due to their high chemical energy and insensitivity in both military and civil fields [1,2,3]
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 polytetramethylene ether glycol (PTMEG)-grafting sample
In the multi-component PBX composite materials, interfacial debonding caused by the large property differences and the incomplete contact between explosive particles and binders leads to the poor mechanical performance of PBXs [6,7,8,9]

Summary

Introduction

Polymer-bonded explosives (PBXs), including energetic materials (EMs) and polymer binders, attracted extensive attention due to their high chemical energy and insensitivity in both military and civil fields [1,2,3]. In this multi-phase system, the interfaces between energetic crystals and polymer substrates, including solid–solid interfaces and solid–gas interfaces produced by small holes, could be critical for practical use. In the multi-component PBX composite materials, interfacial debonding caused by the large property differences and the incomplete contact between explosive particles and binders leads to the poor mechanical performance of PBXs [6,7,8,9]. The interfacial work can be effectively improved by introducing a coupling agent on the explosive’s surface, which acts as a “bridge” molecule [10,11,12].

Methods

Results

Conclusion