摘要： 采用溶胶 －凝胶法制备出水性聚氨酯（WPU）/SiO₂ 纳米杂化物（WPUS），将WPUS和水性聚氨酯乳液复配制得复合涂膜。通过纳米粒度仪测定了 WPUS及不同 WPUS含量复合乳液的粒径及其分布；通过原子力显微镜（AFM）、紫外 －可见光分光光度计、拉伸实验机、视频高速接触角测量仪和吸水率测试等研究了不同 WPUS含量复合涂膜的微观形貌和性能。结果表明：随 WPUS含量增大，复合乳液的平均粒径和多分散指数（PDI）逐渐增大，但都保持在 100nm以内；随着WPUS含量从 2%增大到 10%，涂膜的表面粗糙度增大、SiO₂ 分布变得不均匀，拉伸强度、断裂伸长率都表现出先增大后减小的趋势，在 WPUS含量为 4% ～6%时具有最佳的力学性能；加入 WPUS后，复合膜的耐水性提高、透光率减小，但透光率都保持在 90%以上，其中 700nm处透光率表现出先减小后增大的趋势。

关键词: 水性聚氨酯, 纳米杂化物, 二氧化硅, 溶胶－凝胶法

Abstract: The title nano-hybrid WPUS was prepared by the sol-gel process of tetraethoxysilane and methyltriethoxysilane in the presence of selected special waterborne polyurethane, and used as an additive for modifying water based polymer coating such as polyurethane dispersion. Average particle size and particle size distribution of WPUS and related modified polyurethane dispersion were determined by particle size analyzer. Surface morphology and properties of composite films were investigated by atomicforce microscope(AFM), ultraviolet-visible spectrophotometer, tensile tester, video high speed contact angle instrument andwater absorption test. With the increasing of WPUS content, average particle size and polydispersity index (PDI)increased gradually, and average particle size of composite emulsion was not larger than 100 nm 2% to 10%, surface roughness of composite films increased and distribution of SiO₂  became more uneven, meanwhile, tensile strength and elongation at break showed tendency ofincreasing first and then decreasing; mechanical property of composite films was optimal when WPUS content was between 4%-6% water resistence enhanced and transmittance decreased after addition of WPUS whereas transmittance of the composite films were kept over 90%. In addition transmittance at 700 nm showed tendency of decreasing first and then increasing.

Key words: waterborne polyurethane, nano-hybrid, silica, sol-gel method