聚丙烯/氮磷共掺杂碳点/高岭土阻燃复合材料的非等温热降解动力学研究

Non-Isothermal Thermal Degradation Kinetics of Nitrogen and Phosphorus Co-Doped Carbon Dots/Kaolin/Polypropylene Flame Retardant Composites

为改善聚丙烯(PP)的阻燃性能,通常添加阻燃剂。以氮磷共掺杂碳点(N,P-CDs)和高岭土复配作为协效剂,与聚磷酸铵(APP)、双季戊四醇(DPER)以及PP,通过熔融挤出制备阻燃聚丙烯复合材料(PP/APP/DPER/高岭土/N,P-CDs)。通过Kissinger法和Flynn-Wall-Ozawa法研究阻燃复合材料的热降解动力学,探究阻燃剂机理。结果表明:2%N,P-CDs/高岭土(1.0∶1.0)的加入,明显提高APP/DPER膨胀阻燃剂的阻燃效果,阻燃复合材料的LOI高达29.8%,UL-94通过V-0级。N,P-CDs/高岭土协效剂的加入,不改变APP/DPER的阻燃机理,但其可促进复合材料成炭,减缓热降解速率,增大热降解活化能,提高阻燃材料的热稳定性。

In order to improve the flame retardancy of polypropylene(PP), flame retardants are usually added. Flame retardant polypropylene composites(PP/APP/DPER/kaolin/N,P-CDs) were prepared by melt extrusion using nitrogen and phosphorus co-doped carbon dots(N, P-CDs) and kaolin as synergistic agents, ammonium polyphosphate(APP),dipentaerythritol(DPER) and PP. The thermal degradation kinetics of flame retardant composites was studied by Kissinger method and Flynn-Wall-Ozawa method. The results show that the addition of 2% N,P-CDs/kaolin(1.0∶1.0) significantly improves the flame retardant effect of APP/DPER intumescent flame retardant. The LOI of the flame retardant composite is as high as 29.8%, and UL-94 passes V-0 rating. The addition of N,P-CDs/kaolin synergist does not change the flame retardant mechanism of APP/DPER, but it can promote the carbonization of composites, slow down the thermal degradation rate, increase the thermal degradation activation energy and improve the thermal stability of flame retardant materials.