氢氧化镁/氢氧化铝复合阻燃剂的制备及其在EVA材料中的应用

Preparation and application of Mg(OH)_2-coated Al(OH)_3 composite flame-retardant

采用化学复合方法制备出氢氧化镁/氢氧化铝复合阻燃剂.扫描电镜、X射线能谱仪和X射线衍射仪测试表明,复合阻燃剂颗粒表面粗糙,包覆着纳米级氢氧化镁粒子.通过BET测定,比表面积由包覆前的3.7979m2.g-1提高到15.9414m2.g-1.由复合阻燃剂填充的EVA材料,氧指数可达39.0,拉伸强度达10.2MPa,断裂伸长率达180%,较氢氧化铝原料及氢氧化镁和氢氧化铝机械混合样的阻燃性能和力学性能有显著提高.TG和DTA热分析表明,复合阻燃剂可提高复合材料的分解温度和燃烧残留率,能有效地抑制聚乙烯主链裂解,促进基体成炭,增强复合材料的热稳定性.

Mg（OH）2-coated Al（OH）3 composite flame-retardant was prepared with a chemical compound technique. SEM, X-ray energy dispersion spectroscopy （X-EDS） and XRD were used to investigate the composite flame-retardant, and the results show that the particles of fine Al（OH）3 powder are rough and coated with Mg（OH）2 nanoparticles in the composite flame-retardant. The specific surface area of particles increase from 3. 797 9 m^2·g^-1 to 15. 941 4 m^2·g^-1 by coating. EVA products filled with the composite retardant have superior flame retardancy （the oxygen index is 39.0） and mechanical properties （the tensile strength is 10.2 MPa, the elongation at break is 180%） to those with uncoated Al（OH）3 and the physical mixture of Al（OH）3 and Mg （OH）2. Thermal analysis （TG-DTA） demonstrates that the composite flame-retardant could increase the decomposition temperature and burning residue rate of the EVA products, bate the thermal cracking of polyethylene＇s main chain effectively, and promote the charring.