Progress in non-chromate powder coatings for corrosion protection
The development of non-chromate technologies for powder coatings has been at the forefront of the industry because of the carcinogenic and toxic nature of chromates. In this regard, powder coatings based on nanomaterials, conducting polymers, nontoxic conversion coatings, and ultraviolet (UV) radiation curable powder coatings are some of the new developments on which researchers have focused their attention. This article describes, in detail, the impact that adhesion and corrosion protection parameters have on non-chromate powder coatings and how these new and changing technologies are shaping the industry as it moves forward.
Powder coatings act as an exceptional barrier to the penetration of corrosive species, such as salt water, and can be blended with corrosion inhibiting species to further limit corrosion if film defects do occur in the lifetime of the paint. To optimize the corrosion protective properties of powder coatings, film defects must be kept at a minimum and strong adhesion to the substrate or the pretreatment of the substrate is needed. There is a great deal of research on different parameters that are shown to have an impact on the performance of powder coatings.