Anticorrosive zinc decanoate additive in acrylate varnish

This work is focused on the inhibitory effect of zinc decanoate on steel substrates for improvement of acrylate varnish anticorrosion performance. Experiments were carried out on a bare steel surface in sodium sulphate solution as well as on samples painted with acrylate varnish. The efficiency of inhibition was estimated by electrochemical impedance spectroscopy and an exposure test in a condensation chamber. A cross-section of the modified varnish was observed by scanning electron microscopy. Decanoate mobility on the surface was estimated by energy-dispersive X-ray analysis and infrared spectroscopy. Zinc decanoate provides very good inhibiting efficiency, about 65%. The mobility of decanoate on the surface is limited and it can protect rather small defects. Zinc decanoate can be used as an environmentally friendly anticorrosive additive in varnishes for preservation practice.