水性UV聚氨酯丙烯酸酯/二氧化硅复合材料的制备及涂膜性能

目的 制备光固化水性聚氨酯改性丙烯酸酯/二氧化硅（WPUA/SiO2）复合材料，提高水性光固化聚合物材料的涂膜性能。方法 制备含双键官能化的二氧化硅纳米粒子，将其引入到制备的可光固化聚氨酯改性丙烯酸酯乳液体系中，制备水性UV固化WPUA/SiO2复合乳液，研究复合材料制备方法，分析体系中官能化二氧化硅纳米粒子的分散稳定性及其对涂膜形貌、透光性、硬度等性能的影响。结果 由于WPUA和官能化二氧化硅纳米粒子均含有C==C，所制备的WPUA/SiO2复合材料可以用UV光进行固化，官能化二氧化硅纳米颗粒由于表面存在有机分子链，与水性聚氨酯改性丙烯酸酯相容性提高，使得二氧化硅纳米颗粒掺杂量达到10％（质量分数）时可存储稳定性达30天以上。固化后涂层的透光性和力学性能明显提升，涂层铅笔硬度达到3H，粘附性为1级，抗冲击强度大于50 kg?cm。结论 制备的WPUA/SiO2复合体系具有良好的稳定性，改性纳米粒子的掺杂对水性UV固化聚氨酯改性丙烯酸酯的力学性能有明显改善，且可提高复合涂层的透光性。

Preparation and Film Properties of UV-curable Waterborne Polyurethane Modified Acrylate/Silica Composites

The work aims to prepare photo-curable waterborne polyurethane-modified acrylate/silica (WPUA/SiO2) compo-sites and improve the coating properties of waterborne photo-curable polymer materials. Silica nanoparticle functionalized with a double bond was prepared and introduced into a prepared photo-curable polyurethane-modified acrylate emulsion system to make a UV-curable aqueous WPUA/SiO2 composite emulsion and study the composite material preparation method. The dispersion stability of the functionalized silica nanoparticles in the system and its effect on the morphology, light transmission, hardness and other properties of coating films were analyzed. WPUA and functionalized silica nanoparticles contained C==C double bonds in the system, so the prepared WPUA/SiO2 composite could be cured by UV light. The organic molecular chains on the surface of functionalized silica nanoparticles improved its compatibility with the water-borne polyurethane modified acrylate, so the compound emulsion could be stored for more than 30 days when the silica nanoparticle reached 10 wt% (mass fraction). After curing, the light transmission and mechanical properties of the coating were significantly improved, the pencil hardness of the coating reached 3H, the adhesion was Grade 1, and the impact strength was greater than 50 kg?cm. The WPUA/SiO2 composite system prepared by this method has good stability, and the doping of the modified nanoparticles can improve the mechanical properties of UV-curable waterborne polyurethane modified acrylate and the light transmission of the composite coating significantly.