多壁碳纳米管协效复合膨胀阻燃剂阻燃EVA的研究

Study on Flame Retardant EVA with MWCNTs Synergistic Compound Intumescent Flame Retardant

以乙烯-乙酸乙烯酯共聚物(EVA)为基体树脂,大分子磷氮复合阻燃剂(NPS)为主阻燃剂,以多壁碳纳米管(MWCNTs)为协效剂,制备了低烟无卤阻燃EVA复合材料。采用极限氧指数(LOI)、热重分析(TGA)、扫描电镜(SEM)、力学性能和动态热力学性能(DMA)测试等手段对复合材料进行测定,重点考察了MWCNTs对膨胀阻燃EVA体系的影响,探讨了其作用机理。结果表明:MWCNTs对阻燃EVA体系具有很好的协同效应;MWCNTs的加入提高了膨胀炭层在高温时的热稳定性,增加了高温时的残炭量;MWCNTs可以改善膨胀炭层的形貌,提高炭层的隔热性能;0.5%的MWCNTs与29.5%的NPS复配,试样的LOI达到33.6%,拉伸强度达到12.37 MPa;MWCNTs用量在3%以内时,体系仍能保持较好的电绝缘性。

The low smoke halogen-free flame retardant composites were prepared with ethylene vinyl acetate copolymer（EVA） as the matrix resin, macromolecular phosphorus and nitrogen molecules（NPS） as the main flame retardant, multi-walled carbon nanotubes（MWCNTs） as synergistic agent. The flammability, mechanical properties, thermostability were studied by means of LOI, TGA, SEM and DMA, respectively. The effects of MWCNTS on EVA/NPS were mainly investigated. The results show that MWCNTs has good synergistic effect on flame retardant EVA system, the thermal stability of the intumescent char layer improves and the amount of residual carbon increases at high temperature; then the expansion morphology of carbon layer and the insulation performance of carbon layer improve with the addition of MWCNTs. Adding 0.5% MWCNTs and 29.5% NPS into EVA, the value of LOI and tensile strength could reach to 33.6% and 12.37 MPa, respectively. Furthermore, the electrical insulating performance of system is still good when the amount of MWCNTs is within 3%.