In the journal Nature Lanbin Hu (Liangbing Hu) and his colleagues at the University of Maryland, College Park published an article describing technology to obtain a new highly functional structural material from wood, and described its impressive properties.
“Ultra-wood” is formed by boiling wood block in an aqueous solution of sodium sulfite with the addition of sodium hydroxide. Thus there is a partial removal of wood sturdy structural polysaccharides, lignin and hemicellulose. It would seem that it should weaken her, but then the sample is squeezed between the metal plates of the press (again at 100 °C) under pressure of 5 MPa, i.e. about 50 atmospheres. This impact crushes preserved the most stable polymers, reducing the sample by about 20 percent and making it three times more dense.
Experiments with this material showed that tensile it can withstand is 11.5 times more than the raw samples of the original wood. In fact, this figure is comparable with the properties of good steel, and the “ultra-wood” is much easier for her. But was particularly impressive demonstration of her “bullet-proof” characteristics. The video shows that a projectile moving at a speed of 30 m/s, easily sews conventional wood, but is delayed by a layer of “ultra-wood” of the same thickness.
The authors add that the detailed composition of the solution to obtain a new material depends on the source of wood, but in any case does not involve any expensive or environmentally hazardous substances.
“Ultramarina wood” can become a suitable “green” alternative to traditional steel for the construction of buildings and bridges, vehicle bodies and railway wagons, betrays socportal.info.