目的 利用聚酰亚胺（PI）可溶解于碱性溶液的特性，探究碱溶液改性处理PI基材表面的实验方法。研究NH3?H2O、NaOH和KOH等碱溶液的浓度、温度、时间和处理条件的不同与PI表面改性效果之间的关系，确定最佳改性处理方法。方法 用不同浓度的NH3?H2O、NaOH和KOH溶液在室温或水热条件下处理PI基材。用正交试验确定水热条件的最佳碱浓度、温度和处理时间。样品处理前后的接触角变化用接触角测量仪测定，透光率用紫外可见分光光度计表征，拉伸强度和断裂伸长率用智能电子拉力机测定。结果 实验得出的最佳表面处理条件为：25 μm 厚度的PI基材采用1.0 mol/L NH3?H2O溶液，室温下处理30 min；50 μm 厚度的PI基材采用0.05 mol/L NaOH溶液，水热温度120 ℃，时间90 min。结论 对于厚度为25 μm的PI基材，1.0 mol/L NH3?H2O溶液处理后，表面接触角降低至45°，说明NH3?H2O溶液可有效提高较薄PI基材的表面亲水性。KOH处理后的PI基材亲水性显著提高，但碱液浓度不易控制。采用NaOH水热表面改性方法，能较好地改善PI基材的表面亲水性，从而提高基材与无机涂层之间的界面粘附性。

The work aims to explore experimental method of modifying surface of polyimide (PI) substrate with alkali solution based upon the characteristic of polyimide being dissolved in alkaline solution. Relationship between concentration, temperature, time and treatment conditions of NH3?H2O, NaOH and KOH solutions and modification effect of PI surface was studied to determine the optimal modification method. Polyimide substrates were treated with different concentration of NH3?H2O, NaOH and KOH solutions at room temperature or under hydrothermal conditions. Orthogonal experiments were performed to determine the optimal alkali concentration, temperature and treatment time for hydrothermal conditions. Change of contact angle before and after sample treatment was measured with contact angle meter, light transmittance was characterized with UV-visible spectrophotometer, and tensile strength and elongation at break were measured with smart electronic tensile tester. The best surface treatment conditions acquired by the experiments were: 25 μm thick PI substrates, 1.0 mol/L NH3?H2O solution, room temperature, for 30 minutes; 50 μm thick PI substrates, 0.05 mol/L NaOH, 120 ℃ hydrothermal temperature, for 90 minutes. For the 25 μm thick PI substrates, surface contact angle decreases to 45° after treatment with 1.0 mol/L NH3?H2O solution, indicating that NH3?H2O solution can effectively improve surface hydrophilicity of thin PI substrates. The hydrophilicity of KOH treated polyimide substrates increases significantly, but alkali concentration is not easy to control. NaOH hydrothermal surface modification method can better improve surface hydrophilicity of polyimide substrates, so as to improve interfacial adhesion between the substrate and the inorganic coating.