EVA-g-MAH和滑石粉对金属氢氧化物/LLDPE材料性能的影响

EVA-g-MAH and Talc on Performance of Metal Hydroxide/LLDPE Composites

为提高金属氢氧化物/聚乙烯复合材料的韧性和阻燃性能,以滑石粉(Talc)为阻燃协效剂,马来酸酐接枝乙烯-醋酸乙烯酯共聚物(EVA-g-MAH)为增韧剂,通过双螺杆挤出机和注塑成型制备了氢氧化铝/氢氧化镁/线型低密度聚乙烯(ATH/MH/LLDPE)阻燃复合材料。通过拉伸、冲击、极限氧指数、垂直燃烧试验和扫描电镜研究了ATH/MH、EVA-g-MAH和Talc含量对阻燃LLDPE力学性能、阻燃性能和形貌的影响。结果表明:ATH/MH含量增加,ATH/MH/EVA-g-MAH/LLDPE的拉伸强度和阻燃性能增加,断裂伸长率和冲击强度明显降低。添加EVA-gMAH有利于树脂基体包覆和分散ATH/MH,可同时提高ATH/MH/LLDPE的韧性和阻燃性能。固定阻燃剂(ATH、MH、Talc)总含量为60%,3%~11%Talc部分替代ATH/MH使复合材料的极限氧指数提高1.4%~4.2%,Talc和ATH/MH具有协同阻燃效应,7%Talc部分替代ATH/MH使Talc/ATH/MH/EVA-g-MAH/LLDPE的断裂伸长率和冲击强度分别提高50.0%和13.4%。

To improve the toughness and flame retardancy of metal hydroxide/polyethylene composites,talc(Talc)was used as a flame retardant synergist,maleic anhydride grafted ethylene-vinyl acetate copolymer(EVA-g-MAH)was used as a toughener,and the aluminum hydroxide/magnesium hydroxide/linear low density polyethylene(ATH/MH/LLDPE)flame-retardant composites were prepared by twin-screw extruder and injection molding.The effects of ATH/MH,EVA-g-MAH,and Talc content on the mechanical properties,flame retardancy,and morphology of flame-retardant LLDPE were studied by tensile test,impact test,limiting oxygen index test,vertical burning test,and scanning electron microscope.The results show that as the content of ATH/MH increases,the tensile strength and flame retardancy of ATH/MH/EVA-g-MAH/LLDPE increase,while the elongation at break and impact strength decrease significantly.The addition of EVA-g-MAH is beneficial to the resin matrix wrapping and dispersing of ATH/MH,which can improve the toughness and flame retardancy of ATH/MH/LLDPE simultaneously.When the total content of flame retardants(ATH,MH,Talc)is fixed at 60%,replacing 3%~11%of ATH/MH with Talc can increase the limiting oxygen index by 1.4%~4.2%,and Talc and ATH/MH have a synergistic flame-retardant effect.Replacing 7%of ATH/MH with Talc can increase the elongation at break and impact strength of Talc/ATH/MH/EVA-g-MAH/LLDPE by 50.0%and 13.4%,respectively.