Accelerating New Additive Development through the Use of Automation

By Ingrid K. Meier, J. Renae Bennett, K.T. Griffin Lai, C. James Reader, Tyler Webber, Evonik Corporation, USA

Many additives used in waterborne coatings and inks are complex formulations. For example, most defoamers are comprised of insoluble oils, compatibilizers, and, oftentimes, hydrophobic solids and surface-active species. Since their mechanism of action involves delivering incompatible droplets capable of spreading across and rupturing foam lamellae, it is important to balance this incompatibility with the equally critical requirement that the defoamer not cause defects or recoatability issues in the cured film. Additionally, it is important that the formulated additive resist phase separation under typical transportation and storage conditions. The objective of this article is to share specific details of how a project team developed unique automated test methods and used them, in combination with design of experiments, to accelerate the development of new defoamers and deaerators. Case studies in which the team optimized silicone polyether structures, as well as formulated defoamers, for both performance and stability will be discussed.