Meet 2DPA-1, a new polymer that is as strong as it is lightweight, which can be used to coat car parts, cell phones, build bridges and more.
A team of MIT chemical engineers say they have created “a new material that is stronger than steel and as light as plastic.”
The result of a feat that was once believed to be impossible, the material can easily be manufactured in large quantities.
The secret is in a novel polymerisation process that creates a two-dimensional polymer, which, according to a news release, self-assembles into sheets rather than forming one-dimensional, spaghetti-like chains.
This new material out of say, a Bond movie, or the laboratory of Bruce Wayne, could be used in technology such as “a lightweight, durable coating” for car parts and cell phones, or as “a building material for bridges or other structures,” says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and the senior author of the new study.
“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things,” he enthuses. “It has very unusual properties and we’re very excited about that.”
Two patents are already pending for the process used to generate the new polymer, which the researchers discussed in a paper published in Nature journal on February 2, 2022. MIT postdoc Yuwen Zeng is the lead author of the study.
Researchers say that the new material is between four and six times more resistant to deformation than bulletproof glass and twice as much strength is needed to break it than steel. Even though the new material has all these wondrous qualities, it is only one sixth as dense as steel.
Matthew Tirrell, dean of the Pritzker School of Molecular Engineering at the University of Chicago, says that the new technique “embodies some very creative chemistry to make these bonded 2D polymers.”
“An important aspect of these new polymers is that they are readily processable in solution, which will facilitate numerous new applications where high strength to weight ratio is important, such as new composite or diffusion barrier materials,” adds Tirrell, who was not involved in the study.
Polymers, which include all plastics, are formed of monomers, that are chains of building blocks that grow by adding new molecules onto their ends. Polymers can be shaped into 3D objects such as water bottles by using injection molding, the news release explains.
Even though hypothetically 2D polymers were possible, in reality none of the scientists working in the field was able to create such sheets.
Yet Strano and his colleagues were able to generate a 2D sheet called a polyaramide, using melamine, a type of plastic, as the monomer building blocks. The resulting 2D disks, stacked on top of each other, created a very strong and stable structure.
“Instead of making a spaghetti-like molecule, we can make a sheet-like molecular plane, where we get molecules to hook themselves together in two dimensions,” Strano says. “This mechanism happens spontaneously in solution, and after we synthesise the material, we can easily spin-coat thin films that are extraordinarily strong.”
The material can be produced en masse by increasing the quantity of ingredients which then self-assemble in solution. The researchers demonstrated they could coat surfaces with films of this material, which they named 2DPA-1.
“With this advance, we have planar molecules that are going to be much easier to fashion into a very strong, but extremely thin material,” Strano says.
2DPA-1 is also impermeable to gases, unlike other polymers made from coiled chains with gaps. The new polymer is made from monomers that lock together, preventing molecules from getting between them.
“This could allow us to create ultrathin coatings that can completely prevent water or gases from getting through,” Strano says. “This kind of barrier coating could be used to protect metal in cars and other vehicles, or steel structures.”
Strano and his students are carrying out further research into 2DPA-1’s ability to form 2D sheets and they are looking into altering its molecular makeup to create other types of unique materials.