EG填充无卤阻燃型LDPE复合薄膜阻燃性能研究

Expandable graphite-filled polymer (LDPE) composite film materials for flame retardancy

为了改善聚合物低密度聚乙烯(LDPE)薄膜的阻燃性能,通过向其中添加膨胀型阻燃剂聚磷酸铵(APP)/季戊四醇(PER)和可膨胀石墨(EG),制备了无卤阻燃型低密度聚乙烯复合薄膜。实验研究了膨胀阻燃剂填充聚合物LDPE作为阻燃复合薄膜的性能,分析了膨胀阻燃剂的加入对复合膜阻燃性能、残重率和力学性能的影响机理。研究发现,该新型配方中的EG和APP/PER对复合薄膜的阻燃性能具有协同作用,当配方中APP/PER/EG的填充量达到30%质量分数(APP∶PER∶EG∶LDPE质量比16∶8∶6∶100)时,薄膜材料的氧指数可达到27.5%;与纯LDPE薄膜相比,阻燃薄膜的氧指数提高了10.3%,改善了阻燃效果。

The paper introduces a newly renovated time-retarding material by adding to the retardant the intumescent flame retardant made from ammonium polyphosphate （APP） and pentaerythritol （PER） plus expandable graphite （EG） powder into LDPE. As we know, resin LDPE has always been used to produce plastic films for its lower viscosity and higher melting strength in making films. However, its oxygen index of LDPE is just 17.2% , in addition to its unfavorable feature likely to get ignited, which naturally restrained its applications for packaging. To solve the problem, it is recommended to use environment-friendly intumescent flame retardants, ammonium polyphosphate （APP） / pentacrythritol （PER） and expandable graphite （EG） powder filled in with plastic cables. For the above purposes, the present paper is mainly to introduce the combustion mechanism of low density polyethylene, APP/PER/EG, the influence of adding of APP/PER and EG on the mechanical properties of the composite, with the stress of the preparation process of the flame retardant films and ways for optimizing the formulation of the system of APP/PER/ EG/LDPE. When the flame retardant LDPE films are made, each section temperature of the twin screw extruder should be 165 ℃, 170 ℃ , 170 ℃ , 170 ℃ , 175 ℃ , 175 ℃ . The results of our research show that to some extent, APP/PER/EG may have synergistic effect on the flame retardants of LDPE films. Our research also proves that there exists great potentiality to improve the flame retardancy and an- ti-dripping melting risks by filling such materials as APP/PER/EG. In addition, our tests prove that on the condition when the mass ratio of APP, PER, and EG to LDPE is 16 ： 8 ： 6 ： 100 and the total flame retardant mass content was 30%, there appears the possibility that the LOI was 27.5 % and the tensile strength would reach their highest value, 14.75 MPa.