Revolutionizing construction – sustainable wood protection from tree bark waste

Researchers at Stockholm University have unveiled a fully biobased wood coating system that could transform the construction industry by providing a sustainable alternative to fossil-based synthetic coatings. Inspired by the protective functions of tree bark, this innovative solution, published in the journal Materials Horizons, utilizes components sourced from birch and spruce bark.

Fengyang Wang and Ievgen levchuk. Photo: Matilda Andersson
Fengyang Wang and Ievgen Pylypchuk demonstrate the water resistance of the wood coated with the bark-derived formulation. Photo: Matilda Andersson/SU.

Nature’s ingredients – turning tree bark into high-performance coating

The new coating combines suberinic acids from birch bark and polyphenols from spruce bark, forming a waterborne suspension that is both safe and easy to apply to wood surfaces.

“Polyphenols play a dual role in stabilizing the water-insoluble suberinic acids while also acting as nanofillers to enhance the coating’s mechanical properties, explains Fengyang Wang, the publication´s first author. When applied to spruce wood panels, the bio-based coating exhibited impressive water resistance, outperforming conventional synthetic coatings even after prolonged water exposure.

Turning waste into wealth – a sustainable resource

Picture of wood. Photo: Matilda Andersson.
A closeup of wood with bark-derived water-resistant coating alongside with birch and spruce bark. Photo: Matilda Andersson/SU.

Mika Sipponen, the project supervisor, highlights that tree bark, often burned for energy, can instead be a valuable resource for wood protection. This innovation addresses a crucial need in the construction sector, where traditional wood coatings frequently contain hazardous compounds and rely on fossil-derived chemicals. The new coating provides an eco-friendly alternative without sacrificing performance.

Furthermore, the research aligns with Europe's commitment to improving resource efficiency in the bio-based sector.

"Our approach not only reduces the carbon footprint of construction materials but also creates a circular, sustainable solution in wood processing," Sipponen explains.

Collaboration for a greener future  

Although the materials chemistry was developed at Stockholm University, the research team collaborated across the entire value chain – from bark supply to processing and performance testing. Ievgen Pylypchuk, another researcher involved, emphasizes the importance of interdisciplinary collaboration: "While the bark is locally available in large quantities, it’s crucial to work with various experts."

A bright future for sustainable construction

This discovery holds immense potential for expanding the use of wood in the construction industry while significantly reducing the environmental impact of protective coatings. The breakthrough supports the growing demand for renewable and sustainable materials in modern building practices, positioning wood as a more environmentally responsible construction material.

About the project BarkBuild

The project BarkBuild is funded under the ERA-NET ForestValue initiative, with contributions from the Swedish Energy Agency, Formas, and Vinnova (2021-05015).

For further information, please contact the project supervisor: Mika Sipponen 

Click the links below to read:

About the research project BarkBuild

The publication "Fully bio-based water-resistant wood coatings derived from tree bark" in the journal Materials Horizons