Fully bio-based water-resistant wood coatings derived from tree bark

Area of Science:

• Materials Science
• Forest Products Chemistry
• Sustainable Coatings

Background:

• Wood requires surface protection for durability in construction.
• Current wood coatings predominantly rely on unsustainable fossil-based synthetic materials.
• There is a critical need for eco-friendly alternatives to enhance wood's water resistance.

Purpose of the Study:

• To develop a fully bio-based wood surface protection system using components from birch and spruce bark.
• To investigate the potential of bark extracts as sustainable water-resistant coatings for wood.
• To evaluate the performance of a novel bark-derived coating against conventional options.

Main Methods:

• Formulation of a waterborne coating suspension using suberinic acids and spruce bark polyphenols.
• Utilizing polyphenols for stabilization of suberinic acids and as nanofillers.
• Thermally curing the coating on spruce wood samples.
• Assessing water absorption of coated wood under prolonged water exposure.

Main Results:

• The developed bio-based coating effectively protected spruce wood surfaces.
• A formulation with 10% polyphenol and 90% suberinic acids showed a water absorption of 100 g m⁻² after 72 hours.
• Performance was superior to a standard alkyd emulsion coating, indicating excellent water resistance.

Conclusions:

• Tree bark, often combusted, is a valuable, underutilized resource for wood protection.
• This bark-based coating system offers a sustainable alternative to fossil-based wood treatments.
• The findings support circular economy principles within the wood processing industry.