A wooden 12 times more resistant than natural wood and stronger than many titanium alloys.
Is the “superwood“, developed by engineers of the University of Maryland, in the United States, which found a way of treating wood which makes it as strong as steel.
“We found a solution promising in the search for sustainable materials and high performance,” he told BBC World Liangbing Hu, an associate professor of materials science and engineering in the University of Maryland and leader of the team that developed the new material.
“This type of wood could be used in automobiles, airplanes, buildings and any application where the use of steel”.
The process to transform the wood in a superwood has two steps, as explained Hu.
“The first step is a chemical treatment that partially the lignin (the glue between the cells of the wood),” he said.
“And the second step is the compression of the wood with heat to 100 degrees celsius, which reduces its thickness in about 80%”.
This process allows, according to Hu, “the complete collapse of any void or space, which reduces the defects in the wood and significantly increases their resistance.”
Limit of lignin
A key aspect of the process, according to its inventors, is that the extraction of the lignin must be partial.
Lignin is the second polymer, most common on the planet, after cellulose.
“If compress the wood with heat without removing partial lignin densification of the wood would be very limited and would leave a lot of spaces between the cell walls collapsed,” said Hu.
“And if compress the wood after removing completely the lignin, the whole structure would collapse”.
“But the process of partial removal of the lignin, we have invented allows for a densification complete without the collapse of the structure.”
The scientists from the University of Maryland tested the material by shooting projectiles of steel similar to bullets.
The projectile went through the natural wood, but treated wood stopped the projectile until the half.
“The superwood is strong as steel, but six times lighter, “said Hu to the BBC.
He and his colleagues dealt with the new system three types of hardwoods (lime trees, oaks, and poplars) and three softwoods (species of cedar and pine).
“The treatment works with both hardwoods and soft and grows significantly at the same time its strength and its hardness,” said Hu.
These two properties “are excluded from the greater part of the materials of engineering. But this process demonstrated that it is possible to achieve strength and hardness at the same time”.
Hu ensures that the new wood offering, in addition to its strength and resistance, a material of low cost, abundant, and whose production minimizes the use of fossil fuels that increase carbon dioxide emissions.
“Our densified wood can also be used for a long time, so it will not lead to an increase in the destruction of forests”, he added.
Scientists are investigating now the different applications for the superwood.
And a startup of the university itself, Inventwood LLC, is working to commercialize this technology.
The study by Hu and colleagues was published in the journal Nature.