University of California: Develops shoes that biodegrade in seawater
Scientists have developed shoes that biodegrade in seawater enough for marine life to eat them. Alternatives to plastic could solve the pollution problem plaguing the world's oceans because it's degraded enough to be swallowed by marine life, they say.
Footwear is an important plastic product, shoes account for a significant portion of the world's water and landfill plastic waste, and plastic flip-flops are the most popular shoes in the world. Currently, the plastics that pollute our oceans never degrade, but instead break down into smaller and smaller particles until they become microplastics that survive for centuries. But an interdisciplinary team at UC San Diego has created materials that begin to degrade after just four weeks.
In an interdisciplinary collaboration, a team of experts from biology, polymer and synthetic chemistry, and marine science tracked the samples and found that the material began to degrade after just four weeks in the sea. Afterwards, the researchers identified microbes capable of breaking down and eating the substance from six sites in San Diego.
They biodegraded in land-based composting with previously developed biodegradable polyurethane materials that have turned into the first biodegradable shoes available from their subsidiary Blueview. They were able to trial the biodegradable polyurethane material in an ecosystem close to the coast, where most of the plastic gathers.
The team found a variety of marine organisms that thrived on the polyurethane foam and biodegraded the material back to its original chemical, which was then consumed as nutrients by the same microbes in the ocean. Data from the study, published in the journal Science of the Total Environment, show that a mixture of bacteria and fungi forms a mixture of microbes living throughout natural marine environments.
Stephen Mayfield, a biologist at the University of California, San Diego, said: "There is no single discipline that can address these general environmental problems, but we have developed a comprehensive solution that works on land - and now we know about biodegradation in the ocean too , we have shown that it is absolutely possible to make high-performance plastic products that also degrade in the ocean."
Plastic should never end up in the ocean in the first place, but if these degradable shoes do, the material becomes food for microbes instead of plastic litter and microplastics that harm aquatic life.
