Effects of technical Kraft lignin particles on the performance of anticorrosive epoxy-based coatings

To provide protection against corrosion in harsh environments, high performance anticorrosive coatings are applied on large steel structures. However, to also limit the use of fossil-based ingredients in anticorrosive coatings, there is a growing demand to incorporate renewable raw materials in the coating formulations.

In this study, effects of technical Kraft lignin particles on the performance of epoxy coatings were investigated. More specifically, the corrosion resistance of lignin-based epoxy novolac coatings (L-EN) was evaluated via salt spray exposure testing and compared with an epoxy novolac (EN) coating containing iron oxide pigment, a commercial anticorrosive coating, and a neat EN (i.e. a particle-free binder). Subsequently, to identify chemical changes in the (L-EN) coatings following salt spray exposure, an FTIR measurement was conducted and compared with results for the neat EN coating. Other characterization techniques, such as differential scanning calorimetry (DSC), adhesion and hardness tests, and microscopic analyses, were also applied on the coatings.