Researchers from the University of California San Diego teamed up with a materials science and technology company, Algenesis Materials, to create an algae-based biodegradable material for flip flops.

Commerical-quality biodegradable flip-flops. Source: Stephen Mayfield, UC San DiegoCommerical-quality biodegradable flip-flops. Source: Stephen Mayfield, UC San Diego

Because flip flops are a huge source of waste in landfills, leeching harmful chemicals into groundwater, researchers approached the manufacture of environmentally friendly flip flops with one mission in mind: the life of the material should be in proportion to the life of the product. As such, the team developed a polyurethane foam made of algae oil that can be used to create midsole shoes and the footbed of flip flops. The polyurethane has biobased monomers that meet high materials specifications for footwear while also being biodegradable.

To test the foam’s biodegradability, the team immersed samples of the foam in traditional compost and soil where it degraded after 16 weeks. The team also tested the foam’s toxicity by measuring every molecule shed from the material as it decomposed and identified the organisms that degraded the foams.

Researchers tested enzymes from the organisms and found that they could be used to depolymerize polyurethane products. They proved that they could isolate depolymerized products and use them to synthesize polyurethane monomers. This entire process completes a bioloop.

The full recyclability and biodegradability of commercial products, like shoes, is one way to address waste management and plastic pollution.

The team is working with manufacturing partners to economically produce the new material.

A paper on this new material was published in Bioresource Technology Reports.