可膨胀石墨对聚氨酯半硬质泡沫性能的影响

摘要

Expandable graphite(EG) was added to polyurethane to form flame retardant semi-rigid polyurethane foam(PUF) in one step.The cells structure of pure PUF,EG modified PUF,particle distribution of EG and the morphology of char layer after combustion were observed by scanning electron microscope.The results indicated that EG particles attached to the surface of the cells led to the change of the cells after adding EG particles.The cells of pure PUF changed and carbonized severely,while the foam added EG was covered with thick vermicular graphite after burning.The flame-retardant performance of PUF was studied with vertical-horizontal burning test and limit oxygen index(LOI) experiments.The results showed that the flame retardancy of PUF was reinforced with the increase of the amount of EG.When the content of EG was 12%,the horizontal flame retardant grade of EG modified PUF reached HF–1 and LOI reached 23.9%,which met to the flame retardancy standard.%采用一步法制备了不同含量可膨胀石墨(EG)阻燃聚氨酯半硬质泡沫塑料(PUF).通过扫描电子显微镜观察了纯PUF和EG改性PUF的泡孔结构、EG粒子在泡沫内的分布状态和泡沫燃烧后泡孔和炭层形貌.结果表明,添加EG粒子后,EG粒子附着在泡孔表面,泡孔形貌改变;燃烧后,纯PUF泡孔严重炭化变形,添加EG粒子的泡沫表面覆盖一层浓密的"蠕虫状"石墨炭层.采用垂直–水平燃烧试验和极限氧指数(LOI)试验对PUF的阻燃性能进行了测试.试验结果表明,随着EG用量的增加,PUF的阻燃性能增强,EG添加量为12%时,水平阻燃等级达到HF–1级,LOI达到23.9%,有较好的阻燃效果.