摘要
以植酸(PA)掺杂聚苯胺(PA/PANI)作为光热转换材料和防腐蚀抑制剂构筑了一种光热自修复智能防腐涂层.通过扫描电镜、电化学阻抗及盐雾测试研究了PA与PANI的掺杂质量比(m(PA)/m(PANI))以及PA/PANI的添加量(w(PA/PANI))对涂层防腐性能及自修复性能的影响.结果表明,PA/PANI的加入能够同时提高涂层的附着力、防腐性能和自修复性能.当m(PA)/m(PANI)为 10,w(PA/PANI)为 1%时,PA/PANI在涂层中的分散性最好,涂层的拉拔附着力从 2.06 MPa提升至 3.48 MPa,800 h盐雾测试中未观察到任何腐蚀迹象.经过仅 10s的近红外光照辐射后,涂层的表面划痕几乎完全消失,其阻隔性能得到有效恢复,低频阻抗值(|Z|0.1 Hz)从6.58×105 Ω·cm2 提升至2.25×108 Ω·cm2.
Abstract
Phytic acid(PA)was used as a dopant for polyaniline(PANI)to prepare a series of phytic acid-doped polyaniline composites(PA/PANI)by varying the doping mass ratio of PA to PANI(m(PA)/m(PANI)).Then PA/PANI were employed to fabricate an intelligent anticorrosive coating with photothermal conversion capability for self-healing.The dispersion of PA/PANI in the coating was investigated,and the influence of m(PA)/m(PANI)and PA/PANI loading(w(PA/PANI))on the anticorrosive and self-healing properties of the coating was studied using scanning electron microscopy,electrochemical impedance spectroscopy,and neutral salt spray tests.Results demonstrate that the incorporation of PA/PANI significantly enhances the adhesion,anticorrosive performance,and self-healing capability of the coating,achieving a synergistic effect.When m(PA)/m(PANI)is 10 and w(PA/PANI)is 1%,the dispersion of PA/PANI in the coating is optimal,and the pull-off adhesion strength of the coating is increased from 2.06 MPa to 3.48 MPa.After immersion in a w=3.5%NaCl solution for 28 d,the low frequency impedance at 0.1 Hz(|Z|0.1 Hz)of the intact coating is two orders of magnitude higher than that of the pure resin coating,and no corrosion is observed during the 800 h salt spray test.Following just 10 s of near-infrared light irradiation,the scratches on the coating surface almost completely disappear,and its barrier properties are effectively restored.As a result,it can withstand a 400 h neutral salt spray test,with the|Z|0.1 Hz value increasing from 6.58×105 Ω·cm2 to 2.25×108 Ω·cm2.In contrast,the scratch width of the pure resin coating remains largely unchanged,being accompanied by obvious signs of corrosion.
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