Soft polyurethane foam reinforced by expanded polystyrene particles: Compression performance, strain rate, and cyclic compression response

Abstract The incorporation of particles with soft polyurethane (PU) foam aims to mechanically strengthen the PU foam as PU foam falls short of the mechanical expectation of academia and industries. In this study, the expanded polystyrene (EPS) particles are added to soft polyurethane foam, and composite foam with higher mechanical properties is successfully prepared by one‐step foaming process. The results show that under optimal conditions that is, EPS particle size of 0.5 mm and content of 2.5 wt% (EPS‐0.5‐2.5%), the synthesized foam has the smallest bubble pore diameter of 80 μm and has a stress of 0.284 MPa at 75% strain, which is much higher than that of blank polyurethane foam. As a result of a rise in the quantity of EPS particles, the composite PU foam shows a lower dependency on the strain rate. After the multiple cyclic compression test, PU foam exhibits a descending trend on the stress in the deformation plateau region. Besides, the low‐velocity impact test results indicate that the peak contact force of EPS‐0.5‐2.5% is lower than that of the control group by 632 N.