Scientists have created a dense "bulletproof" wood, light but strong as steel

Scientists at the University of Maryland have developed a technology for making ultra-strong wood that can now be used in places where heavier metals and alloys have traditionally been used and are still used. Moreover, the process of creating such ultra-strong wood is quite simple, it consists in pre-processing a wooden blank in a solution of sodium hydroxide and sodium sulfate at the boiling point of water. These chemicals remove lignin and hemicellulose from the tree, substances that are the basis of its structure and give the tree its strength. After this chemical treatment, the wooden block is compressed between two plates heated to 100 degrees Celsius at a pressure of 5 megapascals, which is 50 times higher than normal atmospheric pressure.

As a result of the sequence of such processing, the volume of the tree is reduced by 20 percent relative to its original volume, and the density of the resulting material is three times the original density. And, thanks to this, the processed dense wood acquires completely new physical properties. It can withstand 11.5 times greater mechanical loads, which puts it on a par with steel in terms of strength, but processed wood, at the same time, is much lighter than steel. As an example of the properties acquired by a compacted tree, the researchers fired steel balls fired from pneumatic weapons at it. And if these balls passed through the untreated wood, then they either bounced off the board of the compacted tree, or got stuck in this board.

The chemicals used to produce compacted wood are not a significant environmental problem. At the same time, almost any type of wood is subjected to the compaction process, from the densest and heaviest varieties to lightweight and less dense varieties. Researchers believe that the new material can become an alternative to the use of steel where environmental cleanliness of buildings and structures under construction is required, for example. In addition, some parts of vehicles can be made from the new wood material, which due to this will become somewhat lighter and consume less fuel or energy. Sourc

e: www.dailytechinfo.org