MG-PF包覆EPS泡沫阻燃及力学性能研究

摘要

The graphite was modified by concentrated acid oxidation method to obtain modified graphite (MG) which has good compatibility with phenolic resin (PF),then the synthesis of PF was done in the MG in order to prepare coating flame retardant (MG-PF) for coating expandable polystyrene (EPS). The MG-PF was applied to coat the pre-foamed EPS,and the flame retardant EPS materials coated with MG-PF were prepared by the secondary foaming method. The modification effects of the graphite were investigated and the effects of MG-PF content and MG content in MG-PF on the flame retardancy and mechanical properties of the materials were studied. The results show that after modifying the graphite,the prepared MG-PF has good stability which improves the flame retardancy and mechanical properties of the materials further. The higher MG content in MG-PF is,the more dramatically the limited oxygen index (LOI) increases with MG-PF content increasing,the lower MG-PF content which makes the horizontal and vertical burning grade of the materials reach HF-1 and V-0 is,but more greatly the mechanical properties decrease with MG-PF content increasing. When the mass fraction of MG in MG-PF is 30%and the mass ratio of EPS and MG-PF is 1∶4, the materials have best comprehensive properties,the compression strength is 219 kPa,the tensile strength is 299 kPa,which meet the requirement of engineering application,and the LOI reaches 25.8%,the horizontal and vertical burning grade is HF-1 and V-0 respectively.%采用强酸氧化法对石墨进行改性，得到与酚醛树脂(PF)有良好相容性的改性石墨(MG)，然后在MG上合成PF，制得可发性聚苯乙烯(EPS)用包覆阻燃剂(MG-PF)，将MG-PF涂覆到已预发泡的EPS珠粒上，经二次发泡成型制得MG-PF包覆阻燃EPS材料。研究了石墨的改性效果，以及MG-PF用量与MG-PF中MG含量对材料阻燃性能和力学性能的影响。结果表明，石墨经过改性后，所制得的MG-PF具有较好的稳定性，从而进一步提高了阻燃材料的性能；MG-PF中MG的含量越高，材料的极限氧指数(LOI)随MG-PF用量增加而提高的幅度越大，水平和垂直燃烧等级达到HF-1和V-0级时所需的MG-PF用量越低，但力学性能随MG-PF用量增加而下降的幅度越大。当MG-PF中MG质量分数为30%，EPS与MG-PF质量比为1∶4时，材料的压缩强度为219 kPa，拉伸强度为299 kPa，满足工程应用要求，且LOI达到25.8%、水平和垂直燃烧等级分别为HF-1和V-0级，具有较好的综合性能。