Researchers from Taiwan investigated the effects of addition of multiwall carbon nanotube (CNT) on the anticorrosion and underwater acoustic absorption properties of polyurethane (PU) coatings. electrochemical impedance spectroscopy, polarization curve measurement, salt spray tests, pull-off tests, and dynamic mechanical analysis were performed to examine the effects on the corrosion and mechanical properties of various coatings while underwater acoustic absorption properties were evaluated using an underwater acoustic impedance tube system. It was found that 0.4 wt.% addition of CNT was increased the the corrosion resistance and adhesion strength of the PU coating.

Addition of 1wt.% of CNT

However, 1 wt.% addition of CNT increased not only the corrosion rate of the coating but also the underwater acoustic absorption properties of the PU + CNT composite coatings.

This article is published on Progress in Organic Coatings, Volume 121, August 2018, Pages 226–235.