Abstract: ［Objective］To address the premature cracking and delamination of steel structurecoatings induced by vibration and thermal deformation in dynamic service environments，this studydeveloped a fast-curing aspartic acid-modified polyurethane topcoat with enhanced weather resistanceand dynamic fatigue resistance. The aim was to improve the long-term protection of steel structuresunder harsh conditions.［Methods］ The effects of key formulation components including the resin system（hydroxyacrylic-aspartic acid hybrid resin），curing agent，and pigment volume concentration（PVC）on coating performance were systematically investigated. The optimized coating was preparedand subjected to comprehensive evaluation through tensile tests，UV aging，thermal cycling，and combined vibration fatigue testing.［Results］At a hydroxyacrylic-to-aspartic acid resin mass ratio of 1∶1 and a PVC of 0.20，the coating demonstrated optimal performance：rapid curing（full drying achieved within 1 hour at 45 ℃）， excellent mechanical properties（tensile strength：7. 3 MPa； elongation at break：140%）， outstanding weather resistance（no chalking after 2 000 hours of UVB aging，with 54. 6% gloss loss）， and superior dynamic fatigue resistance（no cracking or delamination after 20 thermal cycles and 10 million vibration cycles）.［Conclusion］ The aspartic acid-modified polyurethane topcoat demonstrated rapid curing，excellent mechanical properties，high weather resistance，and dynamic fatigue resistance. This significantly extended the service life of steel structuressubjected to temperature fluctuations and vibrational stresses. This work provides a novel solution forthe long-term protection of dynamically serviced facilities.

Key words: dynamic service environment, rapid curing, weather-resistant topcoat, HDI trimer, aspartic acid, polyurethane topcoat

摘要： 【目的】针对动态服役环境中钢结构涂层因振动、温差形变等因素导致的早期开裂与脱落问题，开发一种兼具快速固化、高耐候性和动态抗疲劳性能的天门冬氨酸复合聚氨酯面漆，以提升钢结构设施在恶劣环境下的长效防护能力。【方法】通过系统研究树脂体系（羟基丙烯酸与天门冬氨酸树脂复配）、固化剂类型及颜料体积浓度（PVC）对涂层性能的影响，优化成膜物配比与工艺参数，制备高性能复合涂层。采用拉伸测试、 UV老化试验、耐温变循环及振动疲劳复合试验评估其力学性能、耐候性和动态抗疲劳性能。【结果】当羟基丙烯酸与天门冬氨酸树脂质量比为 1∶1、PVC为 0. 20时，涂层表现出最佳综合性能：45 ℃烘烤 1h即可实干，拉伸强度达 7. 3 MPa，断裂伸长率 140%；经 UVB 2 000 h老化后粉化等级为 0级，失光率 54. 6%；在耐温变循环（20次）加 1 000万次振动疲劳复合试验后无开裂脱落。【结论】该天门冬氨酸复合聚氨酯面漆具有快速固化及力学性能、耐候性、动态抗疲劳性优异的特点，可显著提升钢结构在温差与振动环境下的服役寿命，为动态服役设施的长效防护提供了新方案。

关键词: 动态服役环境, 快速固化, 耐候面漆, HDI三聚体, 天门冬氨酸, 聚氨酯面漆

CLC Number: 

• TQ630. 7