A new lightweight substance is as strong as wood yet lacks its standard vulnerabilities to fire and water.
To create the synthetic wood, scientists took a solution of polymer resin and added a pinch of chitosan, a sugar polymer derived from the shells of shrimp and crabs. They freeze-dried the solution, yielding a structure filled with tiny pores and channels supported by the chitosan. Then they heated the resin to temperatures as high as 200 degrees Celsius to cure it, forging strong chemical bonds.
The resulting material, described in August in Science Advances, is as crush-resistant as wood, says author Shu-Hong Yu, a materials chemist at the University of Science and Technology of China in Hefei. Faster freeze-drying creates even smaller channels and pores, which further strengthens the material, Yu says. And higher curing temperatures increase bonding within the resin and increase the material’s strength, the team found. Adding human-made or natural fibers to the mix could also help.