Project Context and Objectives
Steel is an important building material whose strength and mechanical properties have encouraged its use for centuries. Novel eco-friendly anti-corrosion coatings should ensure its continued use with lower environmental impact.
Steel is subject to corrosion that can reduce service life and lead to collapse in the most severe cases. Protective coatings are commonly applied to prevent contact with moisture and oxygen, but many compounds present in these are now known environmental and public health hazards.
In response to the urgent need for eco-friendly corrosion protection, scientists initiated the STEELCOAT project . They are investigating the use of high-solids solvent-based coatings that have low concentrations of dangerous volatile organic compounds (VOCs) as well as water-based coatings. In addition, they are employing green nanoparticles, conductive polymers and binders to enhance performance.
Nanoceria has been produced by three different methods, liquid method, supercritical method and plasma method. The ceria has been tested for compatibility with conductive polymer dispersions, and binders, both water and solvenborne, as well as used for research into the enhance understanding of the corrosion protection mechanism.
Nanoclays have been surface modified and tested for compatibility with conductive polymer dispersions (water and solvent borne). Conductive polymer dispersions has been developed at different concentration degree, as well as from natural based resources. The dispersions have been tested for compatibility with nanoceria, nanoclays and binders, both water and solventborne.
Binder polymers with inherently high corrosion resistance have been developed for both water and solvent-borne formulations. Also hybrid systems have been developed and tested.
The compatibility with other formulation ingredients has been tested in clear varnishes i.e. formulation of pure binder and binder mixed with cerium oxide and conductive polymer respectively.
The corrosion inhibition has been tested by several corrosive environmental testing methods. All the results from the abovementioned work is confidential.
The potential impact on VOC reduction in the anti-corrosion coatings is huge since only 0.7% of the heavy duty coatings today are based on low VOC or water-borne systems (based on figures from Australia). One of the objectives of the STEELCOAT project is to develop coatings that have VOC contents below 20 g/l for water-borne coatings and 300 g/l for solvent-borne coatings. These values are well below the limits of the EU directive 2004/42/EC for these types of coatings.
One objective of the SteelCoat project is to increase the service life of the coating with 25%. Using a life cycle approach for a 50 year lifetime for 20 200 tons of structural Steel. We can conclude that $136,322 can be saved by using the STEELCOAT coating with 25% extended service life. This amount is almost as high as the cost for the initial coating of the steel construction.
Coating industries can benefit from this technical development, resulting in a sound economical development in this industrial sector with secured employment for a large number of persons. Companies involved in the production of nanoparticles will also benefit from this development since new market segments will be available for these companies, resulting in new jobs.