Bioinspired LM/Al particle reinforced shear stiffening elastomers with improved flame retardancy and thermal conductivity towards thermal-impact protection

Abstract

To expand the application fields of shear stiffening elastomer (SSE), it is highly meaningful to improve its thermal/mechanical properties. Thus, an impact-resistant and fire-retardant elastomer (IFE) is developed through strategic engineering that integrates liquid metal/aluminium hydroxide (LM/Al) particles with SSE. Drawing inspiration from bone joints, which exhibit a dual structure comprising hard components (such as bone) and soft components (like cartilage), the developed IFE successfully balances satisfactory softness with enhanced mechanical performance and thermal conductivity. Due to the B-O crosslinking bonds and the mobility of LM/Al, the healed IFE can dissipate an impact force of 7.13 kN down to 3.76 kN. Furthermore, the IFE achieves the V-0 rating and releases less heat. Compared to SSE (0.177 W m⁻¹ K⁻¹), the thermal conductivity of the IFE with LM/Al particles has increased to 0.302 W m⁻¹ K⁻¹. At 600 s, the computer's temperature drops to 38 °C, which is 13 °C lower than the 51 °C temperature without the use of IFE. Finally, the introduction of this novel bridging strategy significantly improves the thermal and mechanical properties of the IFE while preserving its softness, thereby opening a new avenue for the exploration of advanced materials.