Abstract: magnesium hydroxide (MH) nanoparticles with high dispersibility were prepared by wet precipitation of magnesium chloride and sodium hydroxide at high temperature，and its shape appearance and crystallite characteristics with different hydrothermal durations were investigated with SEM，XRD methods. In addition，its application in ethylene vinyl acetate copolymer (EVA) was studied. The results showed that the grain of MH was hexagonal platelet-shaped and de-agglomerated powders，and the morphology，dispersibility，filter properties and its compatibility with EVA become better with increasing hydrothermal duration. The MH with 3 h hydrothermal reaction showed excellent filter properties，good compatibility with EVA. Its blend with EVA (50/50 wt.) had good rheological and mechanical properties with balance torque 15 N·m，the elongation at break 430%，and tensile strength 11 MPa.

摘要： 以氯化镁和氢氧化钠为原料，采用高温沉淀－水热法制备了高分散纳米片状氢氧化镁，采用扫描电子显微镜和X射线衍射仪对其形貌和晶体结构进行了表征，并在EVA中进行了初步应用研究。结果显示，该氢氧化镁分散性高，过滤性能好，与EVA的相容性好，且随水热时间的增加而进一步改善。经3 h水热改性的氢氧化镁，其填充量为50％的EVA混合物的转矩流变性能和力学性能优良，平衡扭矩为15 N·m，拉伸强度为11 MPa，断裂伸长率达到430％。