UV-Curable Polyester Acrylate Coatings: Barrier Properties and Ion Transport Kinetics Along Polymer/Metal Interfaces

Abstract

Zinc and iron substrates were coated with polyester acrylate films. The samples were cured by an exposure to different doses of ultraviolet (UV) radiation energy at different radiant fluxes of the UV light source. Infrared spectroscopy was used to estimate the resulting degree of macromolecular cross-linking. Its effect on the barrier properties of the coating was investigated by Electrochemical Impedance Spectroscopy (EIS). A reduced water uptake and a reduced swelling of the coating as well as a decelerated diffusion of water through the polymer bulk were detected on polyester acrylate coated zinc samples that were exposed to increasing UV energy doses at low UV light intensity. With the Scanning Kelvin Probe (SKP), a similar tendency was detected for the resistance of polyester acrylate/iron oxide/iron interfaces against cathodic delamination. In contrast, curing with large energy doses at high UV intensity led to decelerated ion transport kinetics along the interface, but did not further improve the barrier properties of the coating. This indicated that SKP data gained on Fe substrates and EIS data recorded on Zn substrates can be correlated if UV curing does not result in strong tension within the polyester acrylate films.

Inhibition of Steel Corrosion and Alkaline Zinc Oxide Dissolution by Dicarboxylate Bola-Amphiphiles: Self-Assembly Supersedes Host-Guest Conception

“…Imperfect substrate coverage would enhance the probability of ahead potential drops within the zone of the supposedly intact interface. This has been reported for UV cured coatings on iron 45 but is absent in the present work.…”

Corrosion protection by hydrophobic silica particle-polydimethylsiloxane composite coatings

“…Water uptake of polymer coatings as well as water diffusion coefficients in the coatings are often used to characterize their barrier properties [26], and this is of particular interest when evaluating hydrophobic coatings.…”

Factors Affecting MoO42– Inhibitor Release from Zn2Al Based Layered Double Hydroxide and Their Implication in Protecting Hot Dip Galvanized Steel by Means of Organic Coatings

“…The EIS spectra of the coated HDG samples with and without LDH/Mo fillers during the immersion in 0.5 M NaCl with and without additions of 0.1 M NaHCO 3 are shown in Figure . Because of the presence of the defect in the polymer layer (an artificial scratch), EIS spectra refer to the corrosion behavior of the metal substrate in the defect and beneath the coating and do not refer to the organic coating; its resistive part would be several orders of magnitude higher. − Moreover, the observed low frequency impedance values are somehow typical for Zn exposed to electrolytes containing a high level of salinity …”