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In a new study, scientists at the University of California San Diego show that their plant-based polymer could offer a viable alternative to traditional petroleum-based plastics.
We know all too well that we have a problem with plastics entering our soils and ocean. According to US environmental advocacy group Ocean Conservancy, 11 million metric tons of plastics enter our oceans every year. This is in addition to the estimated 200 million metric tons that are already there.
This petroleum-based plastic comes from a whole variety of sources including drinks bottles, other types of plastic packaging and resin pellets used in manufacturing.
Much of this plastic will bob on the surface of the ocean for years, such as in the Great Pacific Garbage Patch. It has an estimated surface area of 1.6 million square km – an area twice the size of Texas or three times the size of France. Rather than biodegrade, this plastic will simply break down into tinier and tinier pieces.
These seemingly indestructible pieces of plastic, known as microplastics, measure less than five millimetres long and can take anywhere from 100 to 1,000 years to break down.
The frightening part is that in the meantime these microplastics are being ingested by marine life, and in turn are finding their way into our bodies. Studies have already shown that microplastics have been detected in human arteries, lungs and even placentas. It’s unclear what impact these microplastics will have on our bodies.
As such, researchers are very keen to find viable alternatives to traditional petroleum-based plastics and microplastics that do biodegrade, including plant-based polymers.
New research from scientists at the University of California San Diego and materials-science company Algenesis has shown that the plant-based polymers they have studied do biodegrade – even at the microplastic level – in under seven months.
“We’re just starting to understand the implications of microplastics. We’ve only scratched the surface of knowing the environmental and health impacts,” said professor of chemistry and biochemistry Michael Burkart.
“We’re trying to find replacements for materials that already exist, and make sure these replacements will biodegrade at the end of their useful life instead of collecting in the environment. That’s not easy.”
It was over six years ago that the scientists first started looking at algae-based polymers. While they had data to suggest that the material was disappearing in the compost, they are now able to accurately measure this at the microparticle level.
Having ground the plastic into fine microparticles, the research team used three different measurement tools to confirm that, when placed in a compost, the material was being digested by microbes.
However, the challenge now is using this new material on pre-existing manufacturing equipment that was originally built for traditional plastic. Algenesis has partnered with several other companies to make products that use the plant-based polymers developed at University of California San Diego, including Trelleborg for use in coated fabrics and RhinoShield for use in the production of mobile phone cases.
“When we started this work, we were told it was impossible. Now we see a different reality. There’s a lot of work to be done, but we want to give people hope. It is possible,” stated Burkart.
The paper, written by professors, alumni and former research scientists, has been published in Nature Scientific Reports.
