Measurement of mechanical properties of multilayer waterborne coatings on wood by nanoindentation

Abstract

Abstract Waterborne coatings are widely used for environmental protection. However, they lead to many defects and lower the mechanical properties when applied to wood surfaces. To address this challenge, the effects of multilayer waterborne polycrylic coatings on the mechanical properties of southern pine cell walls were investigated by nanoindentation. The experimental results indicated that the coating layers significantly reduced the elastic modulus ( E r ) and hardness ( H ) values than the wood cell walls. The E r and H values measured along the coating layer thickness direction increased significantly as the distance of the indents to the wood surface decreased. Intact cell walls adjacent to or away from the coating layers had higher E r and H values than partial ones. This study will also be useful in helping to understand the bonding mechanism at the interface between coatings and wood cell walls.