Conducting polyaniline was prepared using acidic phosphate (HPAA) as dopant of emeraldine base (EB)
which can be nano-dispersed in the polyurethane acrylates
and ultraviolet cured polyaniline anti-corrosion coating without any heavy metals was obtained.The surface drying time of this kind of anti-corrosion painting was only 3-5 s under ultraviolet light.Particle size distribution of conductive polyaniline can be controlled from 60 nm to 765 nm
the particle size increased from 60-100 nm to 190-765 nm when the polyaniline loading in the coating increased from 0.5 wt% to 5.0 wt%
accompanied by the increase of porosity of anti-corrosion coating
the reason was due to the agglomeration of conducting polyanilines with increasing polyaniline content.The absolute impedance at 0.1 Hz (|Z|0.1 Hz) of the anti-corrosion coating with 1.0 wt% polyaniline content can maintain 1.0108cm2 after 2400 h immersion in 3.5% NaCl solution
where the ES particle size was 110-180 nm.Moreover
for such anti-corrosion coating with 45-50 m thickness
though red rust was found after 300 h due to the red iron oxide from interaction between conductive polyaniline and mild steel
no blister was found in the coating after 500 h cross scratch neutral salt spray test
and the rusted frontier around the scratch was less than 1 mm
indicating its very nice anti-corrosion performance.