酚醛环氧／环氧树脂复合涂层不同紫外线吸收剂含量时的抗老化性能

Ageing Resistance of Phenol Aldehyde Epoxy / Epoxy Resin Composite Coatings with Various Contents of UV Absorber

为了进一步探讨酚醛环氧/环氧树脂复合涂层的抗老化性能,采用浸渍-提拉法在Q235碳钢表面制备其涂层,并用紫外线老化箱进行加速老化。采用电化学测试技术分析了复合涂层不同辐照阶段的阻水性能,以红外光谱和慢正电子束分析技术对UV-B紫外辐照下复合涂层的化学结构变化进行了推测。结果表明:复合涂层的阻水性能优异,辐照前、中期(<528 h)时的化学结构相对稳定;含紫外线吸收剂(UV-531)的复合涂层抗老化性能大幅提高,在辐照后期(864 h),当UV-531含量为1.5%时,阻水性能最佳,浸泡20 d后低频阻抗依然保持在109Ω·cm2。

Phenol aldehyde epoxy / epoxy resin composite coatings on Q235 steel were prepared by dipping-pulling method,and then the ultraviolet accelerated weatherometer was used to accelerate the ageing of coatings. The water-proof capability of the composite coatings was analyzed by electrochemical measurement during the various irradiation stages,and the changes of chemical structures under UV irradiation were evaluated by infrared spectrum and slow positron beam. Results showed that the composite coatings had excellent water-proof performance,and the chemical structures remained stable during the early and medium stage( < 528 h) of UV irradiation. Moreover,the ageing resistance of composite coatings with UV absorber( UV-531) was increased significantly. In the later stage of UV irradiation,the composite coatings with 1. 5% content of UV-531 had optimum water-proof performance,and the low-frequency impedance still remained 109Ω·cm2after immersion for 20 d.