A new breakthrough by Japanese scientists could potentially be a game-changer.
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Why is plastic waste in our oceans a growing concern?
The biggest selling point of plastic is also its biggest environmental issue: its durability. We use plastic so much because it’s easy to shape, strong and lasts for a long time. However, this has come back to haunt us because it also means that it doesn’t break down when it’s thrown away.
Single-use plastic is theoretically recyclable. The issue is, though, that it often isn’t recycled. In the UK in 2023, around 52% of all single-use plastic was recycled. A lot of this is sent overseas to be sorted and recycled too, meaning it’s difficult to monitor actual rates.
Where does the rest of it go? Either into landfill or straight into the environment. This causes problems because of how long plastic takes to break down, and what happens after.
How long does it take for plastic to biodegrade?
Technically, plastic is biodegradable in the sense that it does break down in the environment. However, it can take centuries for this to happen – the specific time depends on the type. Plastic will never break down into its original components though. Instead, it wears down into smaller and smaller pieces, known as microplastics - pieces that are 5mm or below.
Once they become very small, they can enter marine life, in turn entering the food chain: micro plastics have been found in humans, including in our brains. Unsurprisingly, then, they are a big problem, particularly in the ocean but it’s impossible for us to deal with existing ocean plastic pollution on a microplastic level because of how difficult it is to extract.
The new biodegradable plastic
Dissolvable plastic is such an important breakthrough. Among other things, it doesn’t produce microplastics when it breaks down in the environment.
Japanese researchers at the Riken Center have developed a type of supramolecular polymer. In simple terms, this is a type of plastic where the chemical bonds between molecules are reversible. It was long believed that this subset of plastics was functionally useless because they were brittle and lacked the kind of strength we need. However, this team of researchers found a new chemical bond that makes a strong and highly functional material.
The best part of it? The ingredients used interact with electrolytes found in seawater. Specifically, the “salt bridges” in this new plastic can be broken down when soaked in salty water. Better still, the plastic breaks down into its original components, meaning no microplastics.
On a functional level, it can be moulded and shaped the same as any thermoplastic. However, it doesn’t produce any CO2 emissions because it’s completely non-flammable. It’s also non-toxic, meaning it could be used for food and drink containers.
The researchers found that their new plastics dissolve completely in seawater in 10 hours, and in soil in 10 days. They were able to recover up to 91% of the original ingredients, meaning the products are highly recyclable.
What does this mean?
This new biodegradable plastic is still in its very early stages, but it’s a promising start. Provided it can serve the function of traditional oil-based plastics, there’s no reason why it couldn’t replace them completely.
Although it won’t do anything about the microplastics currently found in the ocean, this plastic is definitely a step in the right direction. Considering we’ll never be able to completely phase plastics out of daily use, switching to one that doesn’t pollute the environment is the next best thing.