钢渣制备水滑石阻燃剂及其在EVA复合发泡材料中的应用

Preparation of hydrotalcite flame retardant from steel slag and its application in EVA foam composites

以钢渣为原料合成了磷酸根型水滑石(P-LDHs),并用十二烷基硫酸钠(SDS)插层P-LDHs得到改性水滑石(SDS-P-LDHs)。分别将P-LDHs,SDS-P-LDHs和膨胀石墨、EVA共混,发泡得到EVA复合发泡材料。利用XRD,XRF,FT-IR,SEM,TEM对P-LDHs和SDS-P-LDHs的形貌结构进行表征。结合极限氧指数(LOI),垂直燃烧(UL-94),SEM,TG,拉伸强度、断裂伸长率等测试,讨论了P-LDHs和SDS-P-LDHs用量对EVA复合发泡材料的阻燃性能和力学性能的影响。结果表明,P-LDHs和SDS-P-LDHs的加入显著提高了EVA复合发泡材料的阻燃性能,可起到良好的成炭作用。相比P-LDHs,SDS-P-LDHs与EVA基体相容性更好,当SDS-P-LDHs添加量为30%(质量分数)时,LOI达到27.5%,UL-94达到V-0级别,拉伸强度和断裂伸长率分别为2.27 MPa和251%,体系综合性能达到最佳。

Phosphated hydrotalcite(P-LDHs)was synthesized from steel slag and modified hydrotalcite(SDS-P-LDHs)was obtained by intercalation of P-LDHs with sodium dodecyl sulfate(SDS).P-LDHs and SDS-P-LDHs were blended with expanded graphite and ethylene vinyl acetate copolymer(EVA),to prepare EVA foam composites,respectively.The surface morphology and structure of P-LDHs and SDS-P-LDHs were characterized by XRD,XRF,FT-IR,SEM and TEM.Combined with limited oxygen index(LOI),UL-94,SEM,TG,tensile strength and elongation at break,the effects of P-LDHs and SDS-P-LDHs on the flame retardancy and mechanical properties of EVA foam composites were discussed.The results show that the addition of P-LDHs and SDS-P-LDHs significantly improves the flame retardant properties of EVA foam composites and can play a good role in charring formation.Compared with P-LDHs,SDS-P-LDHs have better compatibility with EVA matrix.When the addition amount of SDS-P-LDHs is 30%(mass fraction),the LOI reaches 27.5%,UL-94 reaches V-0 level,tensile strength and elongation at break are 2.27 MPa and 251%,respectively.The comprehensive properties of the system are optimal.