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以尼龙6(PA6)为基体,分别用镁铝-碳酸根水滑石(CO3-LDHs)和磷酸二氢根插层改性后的镁铝水滑石(H2PO4-LDHs)作为阻燃剂,制备了PA6/CO3-LDHs和PA6/H2PO4-LDHs无卤阻燃复合材料。通过红外光谱(FTIR)、X射线衍射(XRD)对CO3-LDHs及H2PO4--LDHs进行了结构表征,结果表明:H2PO4-成功插层进入到层间取代了CO23-。通过静态力学测试、极限氧指数(LOI)和垂直燃烧等级(UL-94)的测试,研究了水滑石对材料力学性能以及阻燃性能的影响。结果表明:H2PO4-LDHs更有利于加强PA6阻燃性能和热稳定性,并能在一定程度上提高材料的力学性能。提出了LDH的存在对PA6复合材料燃烧过程的影响机理:水滑石的层状结构能够保护分子链;层间水和结构水的释放能够稀释可燃气体并且降低材料温度;磷酸二氢根属于无机磷化物,受热分解时能够促进聚合物脱水成炭。
PA6 was used as the matrix to prepare the PA6 by using Mg-Al-carbonate hydrotalcite (CO3-LDHs) and H2PO4-LDHs modified by dihydrogen phosphate phosphate as the flame retardant. / CO3-LDHs and PA6 / H2PO4-LDHs halogen-free flame retardant composites. The structures of CO3-LDHs and H2PO4 - LDHs were characterized by FTIR and XRD. The results showed that H2PO4- successfully intercalated into the interlayer and replaced CO23-. The effects of hydrotalcite on the mechanical properties and flame retardancy of the materials were investigated by static mechanical test, limiting oxygen index (LOI) and vertical combustion test (UL-94). The results show that: H2PO4-LDHs is more conducive to enhancing the flame retardant properties and thermal stability of PA6, and can improve the mechanical properties of the material to some extent. The mechanism of combustion of PA6 composites by LDH is proposed. The layered structure of hydrotalcite can protect the molecular chain. The release of interlayer water and structured water can dilute the combustible gas and reduce the temperature of the material. The dihydrogen phosphate belongs to inorganic phosphorus Chemical compounds, when heated to promote polymer dehydration into charcoal.