In addition to aesthetic appeal, coatings are designed to protect the wood from weathering degradation in outdoor conditions. This chapter gives an overview of the effects of the main coating components, coating properties, wood properties and treatments on coated wood performance in service. Understanding how different type of resins, pigments, solvents, and other major additives affect coating performance on wood, helps coating formulators to develop more durable coatings. It is beneficial for both wood scientists and coating chemists to learn which properties of coatings have the highest impact on predicting their service lives when exposed to weathering. For instance, measuring glass transition temperature (Tg) defines the degree of flexibility of a coating. Since wood swells and shrinks due to moisture uptake and subsequent drying, flexibility of a coating plays a critical role in defining its durability on wood in exterior conditions. Similarly, learning how preservative treatment or a new modification technique changes the surface properties of wood will help coating formulators to adjust properties of coatings in way that would have better adhesion and performance on that specific modified wood. Also, the effects of these factors in increasing service life of exterior wood coatings are discussed.
Part of the book: Wood in Civil Engineering