Multifunctional corrosion inhibitors

Development of novel eco-friendly (multifunctional) corrosion inhibitors. 

Electrochemical methods are not usually carried out in the absence of a reference electrode. However, for the rapid screening of multifunctional corrosion inhibitors, the omission of the reference electrode offers the benefit of simplicity whilst retaining the key information regarding inhibition. Figure 9.5 demonstrates the current-potential relationship upon the application of a potential across two electrodes. 

Typically, cooling systems that are to be decommissioned or shut down for a period of time should be stored dry. If this is not possible or if there are dead-legs or other water traps, the cooling water should be deconcentrated and conditions adjusted so that the LSI of the water is approximately +0.5. A conventional, multifunctional chemical inhibitor with a strong anticorrosive action should be used, typically at 3 to 5x the normal dose. The objective is to prevent the onset of corrosion. 

Uses Pigment, corrosion inhibitor, tannin stain blocker, flame retardant, UV stabilizer for use In water- and solv.-based coatings stabilizer for metals and metal salts, esp. zinc, for formulation in zinc-rich coatings food-contact paper/paperboard Features Multifunction ... 

CAS 3775-90-4 EINECS/ELINCS 223-228-4 Uses Monomer, antistat, corrosion inhibitor for catephoretic metal primers, vinyl/acryl reactive resins, water-based resins, adhesive resins Features Multifunctional cation-active can be copolymerized with vinyl or acryl reactive systems exc. wet adhesion on metal low volatility Properties APHA 50 max. clear liq. m.w. 185 vise. < 10 mPa s 97.5% min. purity... 

Multifunctional rare earth organic corrosion inhibitors... 

There are advantages and inherent limitations associated with the use of multifunctional rare earth organic inhibitors for corrosion protection, with the most obvious advantage being the decreased toxicity of these compounds compared with chromate species. This reduced toxicity makes this class of corrosion inhibitors attractive in an industrial sense, as less health and safety issues would arise during manufacture, application and repair. There would also be fewer adverse environmental impacts to consider. 

Anodic inhibitor programs are generally single-drum, multifunctional products and commonly include nitrite and molybdate in addition to other inhibitors and ingredients. The inhibitors provide a corrosion stifling effect resulting from a buildup of corrosion products and by-products on the metal surface. 

A type of waterside maintenance chemical treatment. Any of a very wide range of chemicals that prevent or reduce tendencies of deposition, fouling, scaling, corrosion, or other unwanted phenomena to occur in a water system. Typically for smaller boiler plants, individual inhibitors are blended together to produce various multifunctional formulations specific for particular water chemistry and/or operating conditions. Larger boiler plants tend to use individual active component inhibitors. 

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. 

The sparing solubility of these multifunctional inhibitor compounds lend themselves more readily to incorporation into paints as slow-release corrosion protection. To avoid possible interference of rare earths elements with epoxy polymer coating systems, as has been observed, an encapsulation mechanism may be considered to successfully incorporate rare earth organic inhibitors into paint formulations. This would limit any detrimental interaction, while still allowing the release of an inhibitor as required. 

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