Hollow glass microsphere/polydopamine/glass fiber reinforced composites with high thermal insulation performance by inhibiting conductive and radiative heat transfer

Glass fiber-reinforced polymer (GFRP) is commonly used as an insulating lightweight material because of low thermal conductivity. Due to the increasing demand for lightweight composites with the extreme thermal insulation properties, a highly insulating composite was proposed with inhibiting both conductive and radiative heat transfer. We embedded hollow glass microspheres (HGMs), as a conductive heat transfer inhibitor, onto glass fiber by leveraging the adhesive properties and black color of polydopamine, as a radiative heat transfer inhibitor. The new GFRP integrated with polydopamine and HGMs improved thermal insulation properties by 14% compared with neat GFRP and infrared blocking performance while increasing interlaminar and impact strengths by 48.7%, 28.4% and maintaining similar tensile and compressive strengths. Moreover, it improved flame retardant properties with 27.1% reduction in heat release rate and 25 s of ignition time delay. Based on the excellent multi-functions, it can be applied to industries such as cryogenic container parts.