by Scientists may have found the answer to manufacturing plastic products that actually break down without becoming microplastics, or tiny pieces of plastic that can last for thousands of years.
Researchers at the University of California, San Diego, and materials company Algenesis said they found a way to build plastic with polyurethane, a “bio-based” polyurethane polymer that can compost and break down in the natural environment, compared to conventional petroleum-based. plastic polymers, which are not normally accessible to biological processing, according to a study published in Scientific Reports earlier this year.
MORE: How the UN Plastics Treaty aims to tackle the pollution crisis
But the big question is whether the algae-based material would break down into microplastics — microscopic pieces of plastic that are smaller than one micrometer in size, or smaller than the width of a human hair.
“The argument was always brought back to us, ‘How do you know they’re not making microplastics?'” Skip Pomeroy, a professor in the Department of Chemistry and Biochemistry at UC San Diego and one of the authors of the study, said ABC News.
So the researchers set a goal to prove that their substances don’t microplastic over time because they’re actually being broken down by microbes in the environment, Pomeroy said.
They found a strain of bacteria in compost that could completely survive the plastics made of polyurethane, Michael Burkart, another UC San Diego chemistry researcher and co-author of the paper, told ABC News.
“In the past, we thought we might need many different microbes working together to biodegrade these materials,” Burkart said. “But no, we found one bacterial strain that could survive on these things, so that really means that these materials that we’re making are truly completely biodegradable.”
MORE: Plastic bags from Walmart US bins traced to controversial plastic facilities in Southeast Asia
The organisms that break down the bio-based plastic think the material is similar to leaves or wood they would find in regular compost, Burkart said. And the process – from manufacturing with algae-based materials to breakdown – is 100% renewable, according to the research.
The study shows that their plant-based polymers can biodegrade beyond the microplastic level in less than seven months. Examination of samples after 90 days of aerobic composting showed a 68% reduction in the number of particles. After 200 days, an overall reduction of 97% from the initial count was observed, according to the paper.
Burkart said part of the reason why plastic made from a bio-based polymer has been accepted is because people were skeptical that it could work.
“Some people didn’t believe us,” Burkart said. “They didn’t think that what we were doing – that we were actually making truly biodegradable materials or that it was or was even possible at all.”
MORE: Plastics recycling directory ends, citing lack of ‘true industry commitment’
The accumulation of microplastics in the natural environment is ultimately due to the chemical nature of the widely used petroleum plastic polymer, the researchers said. Microplastics can take hundreds or thousands of years to break down completely.
“We don’t need to be using these materials that will last forever,” said Burkart. “We can really start replacing all these materials that are around us into things that are much more sustainable.”
However, cost is a prohibitive issue for widespread use, the researchers said. While petroleum is readily available to siphon from the ground, widespread use of bio-based polymer plastics will require extensive infrastructure for algae farming, Burkart said.
However, the process devised by the researchers can also be applied to other plant-based materials, Burkart said.
MORE: Irish teenager devises method to remove microplastics from ocean, wins $50K Google Science Fair prize
The researchers hope their new process can eventually be widely applied for food packaging, Pomeroy said.
“But if you’re going to ask me, ‘Could we do this with anything?’ I’m pretty sure we could do this with most anything,” he said.
Scientists have developed a way to completely decompose algae-based plastic appeared first on abcnews.go.com
