目的 以化学键合法替代传统物理包覆法改性纳米氢氧化铝（Nano-ATH）阻燃剂，改善其在有机高聚物中的分散稳定性和相容性。方法 以钛酸酯偶联剂UP-311湿法表面改性Nano-ATH，运用正交实验的方法，研究改性剂用量、改性温度、改性时间对Nano-ATH粒径的影响，并通过红外光谱、粒度及Zeta电位等分析手段对最佳改性条件下制备的Nano-ATH的改性效果进行评价。结果 最佳改性条件为：改性剂用量3%（占Nano-ATH质量的百分比），改性温度75 ℃，改性时间30 min，钛酸酯偶联剂与Nano-ATH以化学键结合。结论 Nano-ATH的表面性能由亲水疏油变为亲油疏水，达到了对Nano-ATH阻燃剂改性修饰的目的。

The work aims to improve the dispersivity and compatibility of nano-sized aluminum trihydroxide (Nano-ATH) flame retardant modified in chemical grafting method instead of traditional physical adsorption method. Wet surface modification of Nano-ATH was carried out with titanate coupling agent UP-311. Effects of coupling agent usage, modification temperature and modification time on particle size of Nano-ATH were studied in orthogonal experiment method. The modification effect on Nano-ATH prepared under optimal modification conditions was evaluated by such analytical means as infrared spectroscopy, particle size and Zeta potential, respectively. The optimal modification conditions were: m (modifier):m (Nano-ATH) as 0.03:1, modification temperature as 75 ℃, and modification time as 30 min. Nano-ATH could be bonded with titanate coupling agent UP-311 by virtue of chemical bond. Surface property of the Nano-ATH powder is changed obviously after modification, the hydrophile-oleophobic Nano-ATH turns into lipophilic-hydrophobic Nano-ATH, and the purpose of surface modification is achieved.