摘要： 【目的】提升混凝土结构表层防护涂料体系的服役耐久性。【方法】将盐酸多巴胺与坡缕石粉末（Pal）按不同质量比分别制得 2种聚多巴胺（PDA）包覆的纳米仿生改性粒子 [Pal@PDA（1∶4）和 Pal@PDA（1∶1）]，随后将其分别引入环氧清漆和聚氨酯清漆中制得纳米仿生环氧封闭底漆和纳米仿生高性能聚氨酯防护面漆，研究了 Pal@PDA（1∶1）掺量对聚氨酯面漆力学性能、耐腐蚀性的影响规律，同时对比了环氧底清漆+聚氨酯面清漆配套体系和纳米复合高性能防护涂层体系的抗氯离子渗透性、耐人工气候老化性及黏结性能。【结果】聚氨酯清漆中引入 Pal@PDA（1∶1）可有效提升漆膜的柔韧性、附着力及耐碱性；当 Pal@PDA（1∶1）的质量分数为 5%时，漆膜拉伸强度和断裂伸长率较纯聚氨酯的分别提升 24. 3%和 40. 3%。与环氧底清漆+聚氨酯面清漆配套体系相比，当纳米复合高性能防护涂层体系中底漆和面漆各含 5%Pal@PDA时，其非稳态氯离子迁移系数降低 36. 6%、1 500 h人工气候老化测试后保光率提高 12. 5%，浸水 1a后的黏结强度同比提升 1. 5倍，达 4. 20 MPa。【结论】基于聚多巴胺的纳米仿生复合高性能防护涂层体系具有更优异的服役耐久性，为混凝土结构的长期保护提供了一种有效策略。

关键词: 聚多巴胺, 坡缕石, 仿生改性, 混凝土防护涂层, 服役耐久性

Abstract: ［Objective］ To improve the service durability of the protective coating systems for concrete structures，a polydopamine（PDA）-based nano-bionic composite coating system was designed and evaluated.［Methods］ Two nano-bionic modified particles，denoted Pal@PDA（1∶ 4） and Pal@PDA（1∶1），were prepared by coating dopamine hydrochloride onto palygorskite（Pal）powder at different mass ratios. These particles were then incorporated into epoxy varnish and polyurethane varnish to formulate a nano-bionic epoxy sealing primer and a nano-bionic high-performance polyurethane topcoat，respectively. The effect of Pal@PDA（1∶1）on the mechanical properties and corrosion resistance of the polyurethane topcoat was examined. In addition，the chloride penetration resistance，artificial weathering resistance，and adhesion of the nanocomposite system were comparedwith those of a conventional epoxy primer plus polyurethane topcoat system.［Results］ The results show that incorporating Pal@PDA（1∶1） into the polyurethane varnish effectively enhanced the flexibility，adhesion，and alkali resistance of the coating film. At a Pal@PDA（1∶1）loading of 5%，the tensile strength and elongation at break increased by 24. 3% and 40. 3%，respectively，relative to pure polyurethane. For the nanocomposite system，in which both the primer and topcoat contained 5%Pal@PDA，the non-steady-state chloride migration coefficient decreased by 36. 6% and the glossretention after artificial weathering was increased by 12. 5% compared with the control system.Furthermore，the bond strength after 1 a of water immersion increased by 1. 5 times，reaching 4. 20 MPa.［Conclusion］ These findings demonstrate that the PDA-based nano-bionic compositeprotective coating system exhibits markedly superior service durability，providing an effective strategy for the long-term protection of concrete structures.

Key words: polydopamine, palygorskite, biomimetic modification, concrete protective coating, service durability

中图分类号: 

• TQ637