目的 研究半酯质量分数对环氧树脂性能的影响，获得较佳参数，制备性能优良的半酯改性环氧树脂。方法 采用半酯法合成半酯改性环氧树脂，通过酸值计算、傅里叶变换红外光谱、接触角和热重分析研究酯化规律及改性树脂的疏水性和热力学性能等。结果 酸值随时间的变化基本符合指数函数。随着半酯含量的增加，接触角虽然整体上呈递减趋势，但在半酯质量分数为50%时，接触角较大；半酯与环氧树脂充分反应，热稳定性较好。结论 成功合成了半酯改性环氧树脂，改性环氧树脂的力学性能和热稳定性得到提高。

The influence of semi-ester mass fraction on the properties of epoxy resin was studied, and the better pa-rameters were obtained to prepare the semi-ester modified epoxy resin with excellent performance. Semi-ester modified epoxy resin was synthesized by semi-ester method. The esterification law and the hydrophobicity and thermodynamic properties of the modified resin were studied by acid value calculation, Fourier transform infrared spectroscopy (FT-IR), contact angle (CA) and thermogravimetric analysis (TGA). The change of acid value with time basically conformed to the exponential function. With the increase of the content of semi-ester, the contact angle decreased as a whole, while the contact angle was larger when the mass fraction of semi-ester was 50%, the semi-ester and epoxy resin fully reacted, and the thermal stability was good. The semi-ester modified epoxy resin was successfully synthesized, and the mechanical properties and thermal stability of the modified epoxy resin were improved.