Increasing the use of wood, for instance in construction, can be quite problematic. Moisture and sunlight, for example, are harmful to wood, which must be protected. Traditional protective agents are chemical substances, some of which are quite toxic. Better options have been developed, although they often impair the durability of the wood.

Coatings typically used to protect wood, concrete, metal, and composite materials are oil-based. They often contain environmentally harmful substances. Coatings based on vegetable oils derived from pine, linseed, coconut, soy, or castor can be more ecologically sustainable, but they are often not resistant to wear and tear. They are frequently combined with synthetic materials. A similar situation applies to volatile hydrocarbons, which are often used in coatings, but they are hazardous to health and also damage the ozone layer. The European Union has restricted the use of several chemical substances used in the production of protective coatings.

Researchers at Aalto University's School of Chemical Engineering (Aalto University) have developed a wood coating made from components found within wood itself. Wood consists of cellulose, hemicellulose, and lignin. The new coating material was developed from lignin. The wood-based coating is safe, inexpensive, and high-performance. It preserves the natural structure and texture of the wood surface, is waterproof, and protects against both stains and discoloration caused by sunlight.

“The coating also very well maintains the wood's ability to breathe,” explains Alexander Henn (Alexander Henn), a doctoral student at Aalto University's School of Chemical Engineering.

Lignin as a coating has many advantages over currently used coatings. It is very effective at preventing corrosion and icing, and it also protects against bacteria and ultraviolet radiation. “Next, we will explore ways to make the coating more flexible,” says Aalto University Professor Monika Österberg (Monika Österberg).