改性氢氧化镁对TPE的阻燃性能研究

Study on Flame Retardant Performance of Modified Magnesium Hydroxide on Thermoplastic Elastomer

本文采用三乙氧基氢硅烷和甲基乙烯基硅橡胶对氢氧化镁(MDH)表面进行改性,并对其进行了表征。X射线光电子能谱(XPS)测试表明,改性后的MDH表面出现了Si及C元素;热重分析(TGA)测试表明,改性后MDH的残炭量得到明显增加。将改性前后的MDH添加到用环烷油改性的(SEBS)与聚丙烯(PP)以质量比为2:1混合得到的热塑性弹性体(TPE)材料中,制备阻燃TPE材料,通过极限氧指数(LOI)和垂直燃烧(UL-94)测试研究了材料的阻燃性能,通过拉伸强度测试研究了材料的力学性能,通过热重分析(TGA)测试研究了材料的热降解行为及成炭性能。测试结果表明,硅橡胶包覆改性后的MDH的添加量达到70wt%时,1.6mm厚度的TPE试样通过UL-94V-0级,LOI值为36.0%,其LOI值略低于纯MDH使用时的数值。TGA测试结果表明,当硅橡胶包覆改性后的MDH添加量为70wt%,与添加未改性的MDH的材料相比,添加硅橡胶包覆改性后的MDH的材料提前降解成炭,800℃的残炭量明显增加。

In this thesis, the magnesium hydroxide (MDH) was suface modified with triethoxysilane and methyl vinyl silicone rubber and characterized. The results of X-ray photoelectron spectroscopy (XPS) tests showed that the Si and C elements apprared on the surface of the modified MDH, thermogravimetric analysis (TGA) tests indicated the modification increased the char residue. The pure and modified MDH was incorporated into thermoplastic elastomer (TPE) consisting of Oil-modified (SEBS) and polypropylene (PP) with the mass ration of 2:1 to prepare flame retardant TPE material. The flame retardancy of materials were evaluated by limiting oxyen index (LOI) and vertical burning (UL丒94) tests, the mechanical properties were investigated by tensile strength test, the thermal decomposition behavior and charring performance of materials was studied by thermogravimetric analysis (TGA). The results indicated that the samples passed UL-94 V-0 rating and the LOI value reached 36.0 % when the loading amount of the modified MDH was 70 wt%, and the LOI value slightly lower than that of pure MDH. The results of TGA demonstrated that the loading amount of the modified MDH stimulated the materials thermal degradation and char-fbnning in earlier stage on heat, and the char residue enhanced obviously compared with pure MDH at 800℃.