Energy absorption and low-velocity impact response of shear thickening gel reinforced polyurethane foam

This paper mainly studies the effect of shear thickening gel on the impact resistance of polyurethane foam. First, flexible polyurethane foams with strain rate sensitivity, shape memory, and impact resistance were prepared by a convenient one-step foaming method. Then, the surface morphology and impact resistance of the composites were characterized by SEM, AFM, and low-velocity impact tests. The results demonstrated that the addition of the shear thickening gel makes the cell size of the composites more uniform and the molecular chain arrangement more regular. When the amount of the shear thickening gel was 20 parts, the surface roughness of polyurethane foams was increased from 14.7 to 74.7 nm. More importantly, the addition of the shear thickening gel significantly enhanced the impact resistance of polyurethane foam. When the impact velocity was 5.5 m s⁻¹, the ratio of absorbed energy to impact energy of the FPUF-15pbw reached 91.35%, which was 20.12% higher than the FPUF-0pbw. (paper)