功能化GO对硬质聚氨酯泡沫阻燃性能的影响

Effect of Functionalized Graphite Oxide on Flame Retardancy of Rigid Polyurethane Foam

通过异佛尔酮二异氰酸酯(IPDI)对氧化石墨烯(GO)进行功能化处理,获得功能化氧化石墨烯(IPDI-GO)与阻燃剂聚磷酸铵(APP)和可膨胀石墨(EG)进行复配,制备出硬质聚氨酯泡沫(RPUF)复合材料。通过热重分析、极限氧指数(LOI)、垂直燃烧测试、锥形量热、扫描电子显微镜和万能拉伸试验机研究了IPDI-GO对RPUF复合材料的热性能、阻燃性能和力学性能的影响。结果表明,功能化后IPDI-GO的热稳定性与残炭率显著提高,并且与膨胀型阻燃剂(IFR)在RPUF复合材料基体中存在明显的协同阻燃作用,阻燃效果与压缩强度均优于GO。相同阻燃剂添加量条件下,添加质量分数0.3%的IPDI-GO就可将只添加IFR的RPUF的LOI从26.8%提高到27.5%,最大热释放速率(PHRR)和热释放总量(THR)分别降低了4.3%和19.0%。与添加GO相比,添加IPDI-GO的RPUF的LOI提高了1.5%,PHRR和THR分别降低了7.8%和15.8%,并且样品残炭率增加,形成炭层更加致密、连续,能够更好地隔绝氧气与热量交换。防火性能指数和火势蔓延指数表明,IPDI-GO的添加使得RPUF的安全性最高,火灾风险性也非常小。另外,压缩强度损失得到明显改善。

The rigid polyurethane foam(RPUF)composite was prepared by compounding IPDI functionalized graphite oxide(IPDI-GO)with flame retardant of ammonium polyphosphate(APP)and expandable graphite(EG).The effects of IPDI-GO on the thermal properties,flame retardancy and mechanical properties of RPUF were studied through thermogravimetric analysis,limiting oxygen index(LOI),vertical combustion tester,cone calorimetry,scanning electron microscopy and universal tensile test.The results indicate that the thermal stability and residual carbon rate of IPDI-GO are significantly improved after functionalization and there is a significant synergistic flame retardant effect between IPDI-GO and intumescent flame retardant(IFR)in the RPUF matrix.Besides,the composites of RPUF with IPDI-GO have better flame retardancy and compressive strength compared with GO.Under the same amount of flame retardant added conditions,the addition of 0.3 wt%IPDI-GO can not only increases the LOI of RPUF from 26.8%to 27.5%,but also reduces the maximum heat release rate(PHRR)and total heat release rate(THR)by 4.3%and 19.0%,respectively.The LOI of RPUF with IPDI-GO is increased by 1.5%compared with GO,while that PHRR and THR decreases by 7.8%and 15.8%,respectively.In addition,it can also increase the amount of residual carbon and form dense and continue residual carbon.The fire performance index(FPI)and fire spread index(FGI)indicate that the addition of IPDI-GO can improve the safety of RPUF composite material and minimize the fire risk according to FPI and FGI,the loss of compressive strength has been significantly improved.