Flip-flops can be great summer shoes, but they are also responsible for a large amount of plastic waste that winds to fill landfills, pollute seashores and float in our oceans. Scientists at the University of California San Diego have come up with a more environmentally friendly alternative: biodegradable flip-flops made from algae.
UC San Diego biology professor Stephen Mayfield told that about three billion pairs of flip-flops are made each year. Surprisingly, these pollute ocean plastics by up to 25%. “We wanted shoes that, if finished at sea, would biodegrade.” “They will also biodegrade on the ground.”
Much more happens before you start imagining the unpleasant feeling of moving back and forth in the hideous sandals made from compact aquatic plant life. The UC San Diego solution involves manufacturing polyurethane foam made from algae oil, which is nonetheless capable of meeting the commercial specification for flip-flop footbeds.
Right now, only 52% of next generation flip-flops are made of biocont. However, researchers are confident that they will get 100% in the future. But even at just current biocontent ratios, flip-flops are capable of biodegrading. In tests, customized foam shoes were immersed in regular compost and soil, where they deteriorated after just 16 weeks.
“Many bacteria and fungi grew abundantly on polyurethane and we were able to separate microorganisms from manure and soil with polyurethane as the sole carbon source,” the researchers wrote in an abstract describing their work. “Scanning electron microscopy and imaging mass spectrometry were used to visualize biodegradation activity. Enzymatic hydrolysis confirmed that the breakdown products were reproductions of the original monomers. These results suggest that it is possible to make polyurethane products that have a biodegradation option for life. “
It is not just flip-flops that new environmentally friendly materials can be used either. “Our polyurethane can be used for foam cushions in chair seats or car seats, for luggage straps, yoga mats, foam insulation and even padding in car tires,” Mayfield said.
A paper describing the work was recently published in the Bioresource Technology Report Journal.