Corrosion protection of magnesium alloy AZ31 sheets by spin coating process with poly(ether imide) [PEI]

Abstract

In the present study, the potential of poly(ether imide) as corrosion protective coating for magnesium alloys was evaluated using the spin coating technique. The influence of different parameters on the coating properties was evaluated and the corrosion behaviour of the coatings was investigated using electrochemical impedance spectroscopy. The best corrosion protection was obtained preparing the coatings under N 2 atmosphere, using 15% wt. solution in N'N'-dimethylacetamide (DMAc) which resulted in a coating of approximately 2 µm thickness, with an initial impedance of 10 9 Ω cm 2 and of 10 5 Ω cm 2 after 240 h of exposure to a 3.5% NaCl solution.

Corrosion resistance of a composite polymeric coating applied on biodegradable AZ31 magnesium alloy

“…No relevant defects were detected, neither in the top image nor in the cross-section. It is reported that the PEI coating morphology can be tuned by changing different parameters such as solvent, atmosphere (humidity), composition, temperature and time of curing [8,10,17]. In the present study the PEI coating showed dense and non-porous morphology (Fig.…”

“…It was reported that PEI coatings protect magnesium perfectly for a short time in sodium chloride solution, allowing for potential application of this polymer for biomedical research. The effect of solvent on coating performance and corrosion protection was investigated by other researchers [10]. However, there are very few reports about the corrosion performance of polymeric coatings in long term tests in physiological media and, in particular, the application of PEI composite coatings in orthopedic implants [9].…”

Laser surface structuring affects polymer deposition, coating homogeneity, and degradation rate of Mg alloys

“…The moderate degradation behaviour of worms coated sample might be attributed to a denser polymeric barrier over the surface, which reduces the exposure of the metallic substrate to the test solution. Furthermore, the porous nature of LbL coating is a relevant parameter affecting Mg degradation rate: in fact Conceicao et al [20] reported that a porous poly(ether imide) coating over a metallic substrate is responsible for a lower degradation rate than a denser one, because in the former case hydrogen is released without excessively damaging the coating and the interface. In addition to role of the coating stability, the degradation process of the Mg alloy is also affected by solution composition, surface morphology and chemistry as well as microstructure [6,21,22].…”

Surface modification of magnesium by functional polymer coatings for neural applications

“…Coatings to prevent corrosion of magnesium are best when they do not let Cl ions through, so the best coating materials are hydrophobic polymers (Conceicao, Scharnagl, Blawert, Dietzel, & Kainer, 2010;Zomorodian et al, 2013). Polylactic acid (PLGA) (Makadia & Siegel, 2011) and polyetherimide (PEI) (Conceicao et al, 2010) both fit these criteria.…”