摘要： 【目的】改善光固化聚氨酯的强度与柔韧性。【方法】使用 N，N-二甲基丙烯酰胺（DMAA）对纳米 SiO₂进行改性并与聚氨酯丙烯酸酯（PUA）复合，制备了 PUA/SiO₂复合树脂。重点研究了改性 SiO₂含量对 PUA树脂及复合膜微观结构和性能的影响。【结果】改性 SiO₂均匀分散于 PUA基体中，且对 PUA树脂黏度影响较小。改性 SiO₂含量为 5%时，复合膜力学性能显著提升，模量、拉伸强度、断裂伸长率分别达到 0. 55 GPa、20. 72 MPa、132. 49%（分别提升 27. 91%、67. 78%、27. 95%），同时保持较高透明性（透光率 91. 25%、雾度 4. 04%）。【结论】制备的光固化 PUA/SiO₂复合树脂在高强度、高柔韧性、高透明性涂层与膜材料领域应用前景广阔。

关键词: 聚氨酯丙烯酸酯, 改性 SiO₂, 复合膜, 力学性能, 光学性能

Abstract: ［Objective］ In order to improve the strength and toughness of UV-curable polyurethane materials.［Methods］ A PUA/SiO₂ composite resin was prepared by compoundingpolyurethane acrylate（PUA）with nano-silica（SiO₂）surface-modified by N，N-dimethylacrylamide（DMAA）. The effects of modified SiO₂ content on the microstructure and properties of PUA resins andits films were investigated systematically.［Results］The modified SiO₂ nanoparticles were uniformlydispersed in PUA matrix and had a slight influence on the viscosity of PUA resin. The mechanicalproperties of composite film were significantly improved at a modified SiO₂ content of 5%. The modulus， tensile strength and elongation at break reached 0. 55 GPa，20. 72 MPa，and 132. 49%（representingincreases of 27. 91%，67. 78% and 27. 95%），respectively，while high transparency was maintained with a light transmittance of 91. 25% and a haze of 4. 04%.［Conclusion］The above composite resin features high strength，high toughness，and high transparency，thus exhibiting broad application prospects in the field of coatings and film materials.

Key words: polyurethane acrylate, modified SiO₂, composite film, mechanical properties, optical properties

中图分类号: 

• TQ630. 4