Mg(OH)2对苯并噁嗪环氧树脂复合材料阻燃性的影响

以Mg(OH)₂为无机阻燃剂,以苯并噁嗪(BZ)-环氧树脂(EP)为基体,通过热压成型制得Mg(OH)₂-玻纤布/BZ-EP层压板。通过垂直燃烧和极限氧指数测试层压板的阻燃性,分析了Mg(OH)₂粉体的用量、粒径及不同粒径粉体复合添加对复合材料阻燃性的影响,通过SEM对 Mg(OH)₂粉体在浸渍胶中的分散结构进行表征。研究发现: Mg(OH)₂粉体的粒径和用量对板材阻燃性有一定影响,不同粒径的粉体混合添加可以在复合材料中形成阻燃网络,达到最佳的阻燃效果,同时可以减小无机粒子对板材力学和电学性能的影响。当阻燃剂Mg(OH)₂用量为BZ-EP总质量的30wt%,粒径为2 μm的粉体(YX-105)和粒径为4 μm(YX-110)的粉体以质量比1:2复合添加时,所制层压板的极限氧指数为34%,垂直燃烧单个试样自熄时间最短为7.52 s,5个试样总自熄时间为49.81 s,达到UL-94V-0级标准。复合材料的弯曲强度为399.84 MPa,相对介电常数为3.848。

Effects of Mg(OH)2 on flame retardant of benzoxazine epoxy composites

Mg(OH)₂-glass fiber fabric/benzoxazine (BZ)-epoxy (EP) laminate was prepared by thermo-compression formation using Mg(OH)₂ as the flame retardant, BZ-EP as the matrix.The flame retardant of the laminate was tested by the vertical flame and the limited oxygen index method.The effects of Mg(OH)₂ powder amount, particle size and compound addition of powder with different sizes on flame retardant of composites were analyzed.SEM was used to characterize the dispersion structure of Mg(OH)₂ powder in impregnation resin.The results indicate that the flame retardant of the laminates is influenced by the particle size and the amount of Mg(OH)₂ powder.The compound addition of powders with different particle sizes makes a flame-retardant net in composites, leading to the best flame retardant effect.And the negative impact of inorganic particle on the mechanical and electrical properties of the laminates is reduced.When the content of Mg(OH)₂ is 30wt% of total mass of BZ-EP and the mass ratio of Mg(OH)₂ powder with 2 μm (YX-105) and 4 μm (YX-110) is 1:2, the limited oxygen index of the laminates is 34%.The shortest self-extinguishing time of single sample in vertical burning test is 7.52 s, and the total self-extinguishing time of the five samples is 49.81 s, which reaches the ranking of UL-94V-0.The bending strength and the relative dielectric constant of the composite is 399.84 MPa and 3.848, respectively.