Cerium-based inhibitors

Using cerium-based inhibitors in eCoat paints... 

Schuman T.P., Shahin A., Staffer J.O. (2002), Cerium based inhibitors of aluminum alloy corrosion, Proc. International Waterborne, High Solids, and Powder Coatings Symposium, New Orleans, LA, February, p. 371. 

Developing rare earth-based inhibitors for paint systems may present different issues. As discussed below, there is a developing body of work on rare earth organophosphates, " and the health risks of these compounds depends more on the oiganophosphate anion than the cerium ion. As can be seen in Table 7.2,... 

Montemor et al., 2006b), zinc (Aramaki, 2002 Garcia-Heras etal, 2004) and stainless steel snbstrates (Pepe et al, 2006). Since cerium-based compounds provide good corrosion protection and are much less toxic than chromates, they have been one of the main candidates as environmentally friendly corrosion inhibitors. 

Although the application of WBE system described by Tan et al. in REM-based corrosion inhibitor research has not been reported, a similar multi-electrode method has been used for the evaluation and selection of REM-based corrosion inhibitors. Muster et al. described a rapid screening approach for the evaluation of candidate corrosion inhibitors including REM compounds. Garcia et al. used this multi-electrode system to study the influence of pH on corrosion inhibition of AA2024-T3 aluminum alloy in O.lMNaCl solution containing potassium dichromate, cerium dibutylphosphate and cerium chloride. 

Forsyth et al. discussed the effectiveness and mechanism of inhibition of a number of novel corrosion inhibitors for mild steel, based on Ce and snbstitnted caiboxylates. The organic component was chosen to be environmentally benign and known to have some inhibitive action in its own right. The componnds included cerium salicylate (Ce[salH]3 H O), cerium anthranilate (Ce[anth]3) and cerium glycolate (Ce[gly]3). Weight-loss measurements were performed over a 7-day time period. Polarization resistance measurements nsnally showed identical... 

F. Blin, S. G. Leary, G. B. Deacon, P. C. Junk and M. Forsyth, The nature of the surface film on steel treated with cerium and lanthanum cinnamate based corrosion inhibitors , Corros. Sci. 48,404 (2006). 

The synergistic inhibition of steel with multifunctional compounds based on cerium(III) and substituted carboxylates was reported by Forsyth et al. in 2002. The work was aimed at developing an environmentally benign inhibitor that provided a high degree of protection to steel in corrosive environments. 

For this reason, corrosion inhibitors such as cerium salts or organic biocides are successfully added to the silane sol-gel layer. Akid and coworkers, for example, have developed a broad range of chromate-free xerogel coatings based on doped Ormosil formulations with very high corrosion resistance and with little evidence of change after extensive salt spray tests for a variety of different metal substrates (aluminum alloys, steel, magnesium, etc.). 

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