Engineering the thermal conductivity of polymer-bonded explosives by interfacial thermal resistance reduction and structural designs: a review

Abstract

Polymer-bonded explosives (PBXs) are a kind of specialized functional composite, exhibiting stringent comprehensive performance requirements due to their significant application value in both military and civil use. Given that PBXs inevitably face thermophysical environments during manufacturing and utilization, thermal conductivity (k) is crucial for them. However, the low k of PBXs leads to the generation of serious thermal stresses when exposed to complex thermophysical environments, resulting in internal cracks or damages that affect their safety and thermal environmental adaptability. Thus, enhancing the k of PBXs is emerging as a critical issue that requires immediate resolution. In this perspective, we holistically present the significant technologies and advancements in the enhancement of k for PBXs. This review first delves into the thermal conduction mechanisms in PBXs composites, including both the theoretical foundations and the factors influencing heat conduction. The theoretical computational studies on heat conduction in PBXs are comprehensively summarized, serving as a vital tool to comprehend and predict heat conduction behavior. Furthermore, considering the distinctive preparation processes and component characteristics of PBXs, the strategies applicable to enhance the k of PBXs are elaborated, which involve the adoption of thermally conductive fillers, the reduction of interfacial thermal resistance, and the design of thermally conductive structures. On this basis, the prevailing challenges and prospects for advancing the k of PBXs are highlighted. This review aims to provide insights and guidance for the rational design and fabrication of thermally conductive PBXs composites or highly particle-filled composites with high k.