A new lightweight material that is stronger than steel

The new material is a two-dimensional polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains.

Such a material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures.

In the new study, researchers came up with a new polymerization process that allows them to generate a two-dimensional sheet called a polyaramide.  

Because the material self-assembles in solution, it can be made in large quantities by simply increasing the quantity of the starting materials. The researchers showed that they could coat surfaces with films of the material, which they call 2DPA-1.

The researchers found that the new material's elastic modulus—a measure of how much force it takes to deform a material—is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.

Another key feature of 2DPA-1 is that it is impermeable to gases. While other polymers are made from coiled chains with gaps that allow gases to seep through, the new material is made from monomers that lock together like LEGOs, and molecules cannot get between them.

This could allow us to create ultrathin coatings that can completely prevent water or gases from getting through. This kind of barrier coating could be used to protect metal in cars and other vehicles, or steel structures.