聚磷酸铵疏水改性及其阻燃聚乙烯的性能研究

利用十八烷基胺对聚磷酸铵（APP）进行表面修饰改性，通过静态接触角对改性后的APP进行润湿性能的测试，其接触角达到了136°，说明改性后的APP具有良好的疏水性能。将改性的APP与成炭发泡剂（CFA）以4:1的比例进行复配后加入到聚乙烯（PE）中，制备阻燃PE材料，并通过氧指数（LOI）和垂直燃烧研究了材料的阻燃性能，通过拉伸和弯曲测试研究了材料的力学性能，通过水煮的方法研究了阻燃材料的耐水性。测试结果表明，与未改性的APP相比，APP的表面改性使得阻燃PE材料的阻燃性能略有降低，但提高了阻燃剂与聚合物的相容性，阻燃PE的力学得到了提高，同时阻燃材料的耐水性能得到了大幅度的提高，其阻燃剂的水抽出率大大降低，当阻燃剂的添加量为25%时，阻燃材料的抽出率仅为0.12%。

Hydrophobic modification of ammonium polyphosphate and its application in flame retardant polyethylene

In this paper, ammonium polyphosphate (APP) was surface modified with octadecylamine and the wettability was measured by static contact angle. The contact angle reached 136°, which indicated the modified APP possessed excellent hydrophobic property. APP and modified APP mixed respectively with char-foaming agent (CFA) with the ratio of 4:1 and added to polyethylene (PE) to prepare flame retardant PE materials. The flame retardant property is tested by the limiting oxygen index (LOI) and UL-94 test, the mechanical property is measured by tensile and bending, and the water resistance of the materials is tested by the boiled method. The results showed that, compared with the unmodified APP, the surface modification of APP slightly decreased the flame retardancy of the PE materials, but improved the compatibility of the flame retardant and polymer which resulted in the enhance of the mechanical property of the flame retardant PE materials. Moreover, the surface modification of APP greatly enhanced the water resistance of the flame retardant PE, and the extraction rate of the flame retardant material is only 0.12% when the loading of the flame retardant is 25%.