| High-power equipment provides convenience and high-efficiency for our daily life,as well as many safety and stability issues.The large amount of heat generated by the equipment can seriously affect the operating efficiency.If the temperature is too high,it may even cause a fire accident.Therefore,thermal management and thermal damage control have become critical technologies that must be solved.Epoxy resin composites are often used as instrumentation materials due to their excellent electrical insulation,adhesion,and mechanical properties,but are accompanied by a series of thermal performance problems: poor thermal conductivity,resulting in slow heat transfer rate and accumulation of heat;poor heat resistance,resulting in easy combustion and release of smoke and gas.In the case of high-temperature emergencies,it is easy to cause accidents.It severely hinders the further development and application of epoxy resin.Inspired by the multilayer structure of onion,alternating stack epoxy resin composites with excellent thermal protection were prepared,the hexagonal boron nitride(h-BN),and expanded vermiculite(E-ver)are used as fillers for heat dissipation layer and thermal insulation layer,respectively.It achieves unique dual functionality of both "avoiding high-temperature hot spots" and "directed rapid heat dissipation" in thermal management.The result shows that the temperature of the top center temperature is 15 °C lower than that of the traditional materials,and the thermal delay time is much improved.An increase in the h-BN content causes an increase in the thermal protection properties of the composites.The thermal mechanism of the anisotropic stacked composites was explained.In addition,we put forward to simple fabrication to exfoliate layered metal hydroxide(LDH)and vermiculite by solid-phases exfoliated strategy.Mg-Al LDH and vermiculite were released in water and assembled into new nanocomposites to preparation of epoxy resin composites.The vermiculite can be used as the supporting skeleton of LDH to improve the thermal stability and form a thermal protection barrier during combustion.LDH can release water and carbon dioxide during combustion,which helps to absorb heat and dilute combustible gases.Vermiculite and LDH synergistically improve the thermal stability and flame retardancy,while also exhibiting superior mechanical properties.The epoxy nanocomposites decreased the peak heat release rate by 29.5%,the total heat release rate by 33.3%,and the char formation increased. |
