▎ 摘　　要

NOVELTY - Wave-absorbing polyurethane composite foam comprises 30-50 pts. wt. polyurethane powder, 40-60 pts. wt. hollow microspheres with coating, 0-10 pts. wt. absorbing filler, 0.1-1 pts. wt. antioxidant, 0.2-1 pts. wt. flowing auxiliary agent and 0.2-1 pts. wt. coupling agent. USE - Wave-absorbing polyurethane composite foam. ADVANTAGE - The spherical surface of the hollow microspheres enables to reduce the stress concentration inside the resin matrix, and synergistically strengthen and toughen the resin matrix with the wave-absorbing filler. The hollow microspheres have a low density (0.3 g/cm3), and the composite material can be made more lightweight by the selective laser sintering process, and the additive manufacturing process does not require molds. The manufacturing cycle is short, and the additive manufacturing process has the characteristics of integrated molding, and also provide a rapid and integral molding preparation method for irregularly shaped wave-absorbing components. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing wave-absorbing polyurethane composite foam, which involves: drying the coated hollow microspheres and wave-absorbing fillers in a vacuum oven at a drying temperature of 80-100℃, Keep the constant temperature for 4-6 hours and then cool to room temperature under vacuum atmosphere, then mixing the dried hollow microspheres and wave-absorbing filler with absolute ethanol and deionized water, adding the coupling agent at the same time, and drying it at 100-120℃ after fully stirring; mixing the modified hollow microspheres and wave-absorbing fillers with polyurethane powder, antioxidants and flowing auxiliary agent and sieve them evenly to obtain polyurethane composite powder materials; The polyurethane composite powder material is 3D printed by selective laser sintering to prepare a wave-absorbing polyurethane composite foam.