Preparation and characterization of SEBS-g-MAH-filled flexible polyurethane foam composites with gradient-changing structure

This study constructs a flexible gradient foaming structure by changes the maleic anhydride-grafted styrene-ethylene/butylene-styrene (SEBS-g-MAH) content on the basis of a two-step foaming technique. The effects of SEBS-g-MAH content and its ratio in the first and second foaming steps on microstructure, compression, quasi-static burst, dynamic cushion, and thermal performance of flexible polyurethane foam composites are investigated. Results show that, SEBS-g-MAH content affects microstructure, compressive stress, burst strength, dynamic cushion and thermal performance. Gradient foaming improves compressive stress and quasi-static bursting strength by 3.81 and 1.56 times, respectively. The absorbed energy under dynamic impact of gradient foaming can be increased by 87% relative to that in one-step foaming. This study provides a new way approach to SEBS application, and serves as a new reference for designing of energy-absorbing foam composites by filler addition.