Researchers from Rutgers University have figured out a way to make plastics that can be programmed to self-destruct. What’s more, this innovation has been achieved without the use of new chemicals but through the use of polymer molecules folded in space.
This is a big deal because current plastics are designed to be extremely durable. Nature’s polymers (like DNA, RNA, proteins), on the other hand, aren’t durable forever.
In other words, they do their job, then fall apart naturally. Inspired by this, the Rutgers team set out to discover how to give synthetic plastics a similar “built-in end-of-life.”
Natural polymers degrade because their internal structure makes certain bonds easy to break when bumped by water, light, or small chemical changes. Synthetic plastics also have bonds that could break, but their shape prevents it.
This plastic will self-destruct
In other words, the bonds are shielded. To this end, the Rutgers team wondered what would happen if a polymer were folded such that its vulnerable bonds were exposed when needed?
To achieve this, they used something called conformational preorganization. This is basically the pre-folding of the molecule in such a way that, when the right moment comes, a specific bond is easy to snap.
The science is quite complex, but you can think of it like folding paper along a crease, introducing weaknesses that enable it to tear easily later. If you don’t fold it, it becomes nearly impossible to tear it cleanly.
And so, the team purposely introduced similar “creases” into the plastic. To achieve this, the team used a normal type of bond that exists in many plastics but rarely breaks.
Then they added small chemical groups placed right next to that bond, so they can swing into position and snap it when water or other triggers nudge them.
By changing the exact geometry of those helper groups, they can make the plastic degrade in a matter of days, months, or years. This means the very same material can be designed to have a different lifespan just by tweaking the angles.
More work needed
Because this doesn’t require weird chemicals or fragile materials, the idea could be applied to various real-world products like short-life plastics. It could also be used for things like food containers, packaging, and single-use items designed to hold shape for hours, then fall apart days later.
It could also find applications for more long-lasting plastic products like car parts or building materials. In either case, they could be designed to last decades, then slowly degrade when exposed to the environment.
According to the team, the new plastics even showed they can use light or metal ions as triggers, like an on/off switch for degradation. As great as this all sounds, the new materials have only been created and tested under laboratory conditions to date.
Much more testing is required before taking them to market, especially to ensure they are safe to use. They also need to be incorporated into real, everyday plastics
and need industrial manufacturing compatibility testing,
That said, conceptually, it’s a new toolkit for redesigning plastics without changing the basic chemistry.
You can view the study for yourself in the journal Nature Chemistry.