Bioinspired corrosion and abrasion protection for steel structures
Polybenzoxazine (PBZ) is a kind of high corrosion-resistant polymer, however, the brittleness and weak adhesion strength of PBZ have puzzled their applications. In a new work, researchers have introduced ether amine molecules into benzoxazine monomers via molecule design, and then copolymerised them with tannic acid (TA) to realise flexible PB-TA coating systems, aiming at achieving durable corrosion and abrasion protection for steel structures. It is found that the PB-TA copolymer gains favorable plasticity up to 39.44 % elongation.
High corrosion resistance
Meanwhile, TA provides more active sites and stronger hydrogen bond interaction, which increases the crosslinking density of PB-TA coating and achieves a high adhesion strength (13.57 MPa) to the mild steel substrate. Further experiments evidence that the PB-6TA coating (with 6 % mass of TA addition in the PBZ) presents high corrosion resistance (>109 Ω.cm2 after 600 h salt spraying test), far beyond polyurethane and epoxy resin coatings. Also, the PB-6TA coating exhibits a higher anti-friction ability during cyclic wear corrosion test than the pristine PBZ coating.
The study has been published in Progress in Organic Coatings, Volume 174, January 2023.