Super wood material can replace steel

Posted Feb 9, 2018 by Tim Sandle
A new process has the potential to transform wood into a material that is as strong as titanium alloys, but one that is also lighter and less expensive.
Patterns of narrow and wide tree rings correspond to dry and wet years.
Patterns of narrow and wide tree rings correspond to dry and wet years.
Daniel Griffin
Researchers from the University of Maryland have discovered the means to transform wood into a material that is over 10 times stronger and tougher than before. The outcome is to create a natural substance that is far stronger than many types of titanium alloys.
The process of creating the material is called wood densification. remarkably the process results in both increased strength and toughness. These two properties are typically offset by each other. Te process involves two-steps. First, there is the partial removal of lignin and hemicellulose from the natural wood. This happens by boiling in an aqueous mixture of sodium hydroxide and sodium sulphite. The second step is a form of hot-pressing.
The most complex part of the development with controlling the concentration of lignin. This is the glue-like substance found between wood cells. Getting this right helps to maximize the mechanical performance of the densified wood.
The new wood based material is as strong as steel, but it is also six times lighter. Furthermore, it requires 10 times more energy to fracture compared with natural wood. The material is also flexible and it can be bent and molded, at the beginning of the manufacturing process. The researchers are of the view that the developed wood material could be used in cars, airplanes, buildings, in fact to replace anything that currently relies on steel.
According to lead researcher Dr. Liangbing Hu, the new material "could be a competitor to steel or even titanium alloys, it is so strong and durable. It's also comparable to carbon fiber, but much less expensive."
The research has been published in the journal Nature. The research paper is headed "Processing bulk natural wood into a high-performance structural material."