학술논문

Self-healed microcracks in polymer bonded explosives via thermoreversible covalent bond and hydrogen actions
Document Type
article
Source
Defence Technology, Vol 28, Iss , Pp 183-194 (2023)
Subject
Polymer bonded explosives
Self-healing polymers
Diels-alder (DA) bonds
H-bond
Military Science
Language
English
ISSN
2214-9147
Abstract
Polymeric materials used for the polymer bonded explosive (PBX) or other energetic composite materials (ECMs) that simultaneously possess excellent mechanical properties and high self-healing ability, convenient healing, and facile fabrication are always a huge challenge. Herein, self-healing linear polyurethane elastomers (PTMEG2000-IPDI-DAPU, denoted as 2I-DAPU) with high healing efficiency and mechanical properties were facilely fabricated by constructing reversible covalent bonds and dynamic hard domains into polymer chains. Furthermore, a TATB-based PBX using as-prepared 2I-DAPU polymer as the binder was constructed, disclosing an excellent self-healing property to heal cracks generated during fabrication, transportation and storage. The damage healing manner of such a PBX sample was investigated by means of prefabricated damage through mechanical load, heal treatment via heating at high temperature, and CT-scanning the inner structure and mechanical property characterization via Brazilian test. The self-healing mechanism of internal damage in PBX was preliminarily explored. We propose that this 2I-DAPU binder with Diels-Alder bonds could generate plentiful active surface groups resulting from damage and drive self-healing at fitting temperature and increase the slightly packed hard phase via incorporating a small amount of hydrogen bonds. This work may offer a novel strategy for improving mechanical property and healing ability in the field of self-healing material which could help expand its applications with enhanced versatility in mechanical-enhanced functional materials.