用正交设计法研究阻燃LDPE薄膜配方

On the formulas of flame-retardant low-density polyethylene films by using orthogonal plan method

以低密度聚乙烯LDPE、氢氧化镁和微胶囊化红磷为原材料,利用正交设计法研究了新型阻燃薄膜配方,制备了阻燃型低密度聚乙烯薄膜,并对其氧指数进行测试。结果表明,新型配方中的氢氧化镁和微胶囊化红磷具有协同阻燃效果,并能在一定程度上解决燃烧时的熔滴现象;当氢氧化镁添加量小于29%时,两种阻燃剂对体系阻燃性的影响差别不明显;与纯LDPE薄膜相比,阻燃LDPE薄膜由于添加了上述两种阻燃成分,体系氧指数提高4%,改善了阻燃效果。

This paper aims to introduce the authors＇ research on the formation of flame-retardant low-density polyethylene films by using the orthogonal plan method low density polyethylene （LDPE）. As we know, resin has always been used to produce plastic films for its lower viscosity and higher melting strength in making films. However, the oxygen index of LDPE was only limited to 17.2, in addition to its feature prone to get ignited. Therefore, it is dangerous to be used for ammunition packing. To solve the problem, it is recommended to use environment-friendly flame retardants, magnesium hydroxide and micro-encapsulated red phosphorus filled in plustie cables. But little is reported at home on the use of magnesium hydroxide and micro-eneapsnlated red phosphorus in this way. The present paper is mainly to introduce the combustion mechanism of low density polyethylene, the flame retardant mechanisms of magnesium hydroxide and micro-encapsulated red phosphorus and the preparation process of the flameretardant films. The orthogonal design experiment is used to optimize the formulation of the system of magnesium hydroxide /micro-encapsulated red phosphorus/low density polyethylene, and flame retardant LDPE fihns were prepared. According to the layout, 3 levels with 3 factors （33） , their limited oxygen indexes were examined by a limited oxygen index apparatus. The results show that to a certain extent, magnesium hydroxide and red phosphorus had synergistic effect on the flame retardant of LDPE films. It proves to be possible to improve the flame retardaney and anti-dripping melting by filling magnesium hydroxide and red phosphorus. While the flame retaidant LDPE films are made and when each section temperature of the twin screw extruder was 150℃ , 155℃ , 160℃ , 170℃ , 180℃ , 185℃ , and the dominant factor was MH, the optimized formulation of flame retardant LDPE films with low density polyethylene was 100, with magnesium hydroxide, was 40, and with micro-encapsulated red phosphorus, was 10. Thus, the limited oxygen index can be improved over 4 percent than that of pure LDPE ones, that is, 21.2.