Researchers at the University of Maryland have developed a method to make wood more than 10 times stronger and tougher than before which can make it a strong competitor for steel as a building material. These researchers have developed a two-step process that produces dense wood with a specific strength higher than that of most structural metals and alloys, making it a lightweight and low-cost alternative for building projects.
According to the researchers treated wood is as strong as steel, but six times lighter. It takes 10 times more energy to fracture than natural wood. It can even be bent and molded at the beginning of the process.
In the first step of the two-step process developed by the researchers, lignin and hemicellulose substances of the wood will be partially removed. This is done by boiling wood in a mixture of sodium hydroxide (NaOH) and sodium sulphite (Na2SO3). In the second part, the wood is put through a hot-rolling process, which causes what is left of the cell walls to collapse. This process makes the wood more dense characterised by tightly aligned cellulose nanofibres. Same process is used irrespective of the species of tree.
The process makes softer wood as strong or even more stronger than teak wood. As a result, one could grow soft wood like pine or balsa which grow fast and are more environmentally friendly, and could replace slower-growing but denser woods like teak in furniture or buildings. Eventually, the technology has the potential to replace even steel.