Low-temperature plasma polymerization of dicyclopentadiene for anti-corrosion properties

We successfully synthesized plasma-polymerized films from a highly crosslinkable monomer, dicyclopentadiene (a norbornene derivative), using a low-temperature plasma process as an anti-corrosion coating for Cu metal plates. Plasma-enhanced deposition of polymer films from a dicyclopentadiene precursor was carried out using radio frequency (13.6 MHz) plasma generation with argon or nitrogen carrier gas and varying the input power (50-200 W). The surfaces of plasma-polymers synthesized using an argon carrier gas were more hydrophobic than those prepared with a nitrogen carrier gas, which can be attributed to the formation of C-N-CH_x bonds due to nitrogen dissociation. The inhibition efficiency (IE) for Cu corrosion was estimated from potentiodynamic polarization curves to be enhanced up to ∼93%, which was proportional to the input power in the polymer synthesis. Interestingly, when using a nitrogen carrier gas, the plasma-polymerized films showed shifts of the corrosion potential to negative values. We suspect that nitrogen insertion into the films may result in polarization between nitrogen and copper atoms.