They have been working on producing the material for eight years and it has been designed to replace conventional plastic packaging. It is composed of polyurethane foam and dissolves in seawater and land-based composts. The researchers worked alongside marine biologists to test the material in natural nearshore ecosystems, which is where disposed plastic is most likely to end up.
Improper disposal of plastic in oceans has led to an environmental crisis, but the research team believe this new biodegradable packaging could make advances in solving plastic pollution issues in our oceans.
The dangers of plastic pollution
Plastic pollution is a global environmental issue, becoming a rising threat to both humans and the world we live in. Around the planet, plastic pollution stretches from shopping bags in the ocean to microplastics in both our food supply and blood.
In 2010, scientists estimated that eight billion kilograms of plastic disposal enter the ocean every year, with a huge increase expected by 2025.
Plastic waste is disruptive to marine ecosystems, eventually migrating to central locations and forming huge compositions of plastic disposal. The Great Pacific Garbage Patch is the largest, covering an area of more than 1.6 million square kilometres. Shoes, including flip-flops, make up the largest percentage of plastic waste in our oceans and landfills.
Stephen Mayfield, a professor in the School of Biological Sciences at the University of California, explained: “Improper disposal of plastic in the ocean breaks down into microplastics and has become an enormous environmental problem.”
Conventional plastics never fully decompose, instead breaking up into smaller particles and turning into microplastics that persist in the environment for centuries.
Biodegradable packaging: Would it solve plastic pollution in oceans?
When running tests on the new material, the team discovered that marine organisms colonise on the polyurethane foam and biodegrade the material back to its starting chemicals. Microorganisms, such as bacteria and fungi, live throughout the ocean and are able to consume the packaging’s chemicals as nutrients.
“We’ve shown that it’s absolutely possible to make high-performance plastic products that also can degrade in the ocean. Plastics should not be going into the ocean in the first place, but if they do, this material becomes food for microorganisms and not plastic trash and microplastics that harm aquatic life,” Mayfield said.
The team carried out further tests on the biodegradable packaging with experts in biology, polymer and synthetic chemistry, and marine science. They exposed their polyurethane foam samples to tidal and wave dynamics and tracked for molecular and physical changes using infrared spectroscopy and scanning electron microscopy.
Results of the test showed that the material started to decompose in as little as four weeks. The team also found microorganisms from six different marine sites that are capable of breaking down and consuming the biodegradable packaging.
“No single discipline can address these universal environmental problems but we’ve developed an integrated solution that works on land—and now we know also biodegrades in the ocean,” Mayfield concluded. “I was surprised to see just how many organisms colonize on these foams in the ocean. It becomes something like a microbial reef.”