Abstract: The development of environmental friendly polyurethane foams is a focus in polyurethane industry. By introducing soy protein isolate（SPI）and flame retardant polyols into polyurethane（PU），environmental friendly flame retardant high resilience flexible polyurethane foams were prepared by free foaming. The effects of SPI content and addition manner on the physical，mechanical，biodegradability，and flame retardant properties of PU foams were investigated. The results show that，introducing SPI by adding not by substituting for polyols is an effective way to improve the performance of PU foam. By adding a small amount of SPI，the open cell ratio，elongation at break，resilience，comfort factor，density，and indentation force deflection value of PU foam are increased，while the tensile strength，limited oxygen index，and compression set value are slightly affected. SPI changes the structure of rigid segments，hence effectively enhances the biodegradability of PU foam.

Key words: soy protein isolate, polyurethane foam, biodegradability, flame retardant, resilience

摘要： 开发环境友好型聚氨酯是目前聚氨酯（polyurethane，PU）泡沫塑料领域的热点课题。在PU中引入大豆分离蛋白质（soy protein isolate，SPI），采用阻燃聚醚制备了环境友好型阻燃高回弹聚氨酯软泡。研究了SPI的不同添加方式及用量对聚氨酯软泡物理、力学、阻燃和生物降解性能的影响。结果表明，SPI以添加的方式而不是替代聚醚的方式加入软泡性能更好；少量添加SPI可以提高PU软泡的开孔率、密度、压陷硬度、舒适因子、回弹率和断裂伸长率，对压缩永久变形率、拉伸强度和极限氧指数影响不大。SPI改变了PU的硬段结构，可以有效促进聚氨酯泡沫的生物降解。

关键词: 大豆分离蛋白, 聚氨酯泡沫塑料, 生物降解, 阻燃, 回弹率