UD scientists and employees urgently call for action against plastic pollution

Image Credit: Graphics by Jeffrey C. Chase

Humans have lived without plastic for the last century or so, but most of us find it hard to imagine how.

Plastics are everywhere in our lives today, offering inexpensive convenience and other benefits in myriad applications. They can be shaped for almost any task, from thin films to squishy kids’ toys to hardcore components. They have been shown to be essential in medicine and have been instrumental in the global effort over the past 16 months to slow the spread of the COVID-19 pandemic.

Plastics seem indispensable these days.

Unfortunately, they are also almost indestructible in the long run. Our planet now weighs more than seven billion tons of plastic, and more is being produced every day. A steadily growing waste stream is clogging our landfills, polluting our waterways and creating an urgent crisis for our planet.

Four scientists have published a call to action in a new issue science, is dedicated to the plastic problem.

In a comprehensive introductory article, the scientists – including two from the University of Delaware, one from the Lawrence Berkeley National Laboratory in California, and one from the University of Sheffield in the UK – call for a fundamental change in the way plastics are designed and manufactured , used and reused.

The ultimate goal: to design, introduce and ensure a “circular” life cycle for plastics that does not lead to a landfill or an ocean or a roadside, but to a long lifespan of the almost unlimited use and reuse of the valuable resources and applications they represent .

That requires new approaches to chemistry, engineering, industrial processes, politics and global collaboration, according to co-authors LaShanda TJ Korley, director of the Center for Plastics Innovation (CPI) at the University of Delaware and principal researcher of a National Science Foundation (NSF) partnerships for international research and education efforts in bio-inspired materials and systems; Thomas H. Epps, III of UD, co-director of CPI, senior research director of an NSF Growing Convergence Research (GCR) initiative in materials lifecycle management, and director of the Center for Hybrid, Active, and Responsive Materials (CHARM) at UD; Brett A. Helms of the Molecular Foundry at Lawrence Berkeley National Laboratory in California; and Anthony J. Ryan of the Grantham Center for Sustainable Futures at the University of Sheffield in the UK.

“The plastic waste dilemma is a global challenge that requires urgent intervention and a concerted effort that connects partners from the industrial, academic, financial and government sectors, backed by significant investments in sustainability,” they write.

It is a big task that involves paying attention to recycling, “upcycling” (reusing materials in new ways with added value), developing new materials and recognizing the needs of underserved communities.

“There is no one-size-fits-all solution,” says Korley, Distinguished Professor of Materials Science and Engineering at UD, who has spent her career developing new plastics with specific properties. “How people live with waste and how they recycle is so different. Traveling in Europe has shown the stark contrast in the use of single-use plastics such as drinking straws and cutlery compared to the US. In the US, cities and towns within a single state can do things differently. “

Many plastics use complex formulations, Korley said, and often contain multiple types of polymers and other additives. Any component can make recycling efforts difficult or impossible, which is why recyclers accept some types of plastic and reject others.

But how can plastics be designed so that all of their components can be broken down for future use in other products?

This is the challenge for CPI that Korley leads. The focus is on the “upcycling” of plastics – the search for ways to convert plastic waste into valuable materials such as fuels and lubricants. Researchers use catalysis and enzymes to reconstitute some types of plastics, such as: B. High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE), and Polystyrene / Styrofoam, which are used in milk jugs, shampoo bottles, sandwich bags, and coffee cups, grocery bags, and food packaging.

“Different material properties require the use of different polymers and blends and additives, which adds complexity and hierarchy to waste,” said Korley.

The science Paper deals with this and much more, with an urgency that reflects the real and present dangers to a planet suffocated by discarded plastic that is going nowhere for the foreseeable future.

Some of these realities are grim indeed. Take, for example, the plastic water bottle that helped quench your thirst after a morning jog five years ago. It will probably stay with us – somewhere – for another 395 years. Slow decay doesn’t help us either. Scientists have found that tiny microparticles of worn plastic are widespread in the water we drink and the food we eat.

Less than 10% of plastic waste is recycled at all and less than 1% is recycled more than once. About 12% are burned. Millions of tons of discarded plastic end up in huge vortices of rubble in the sea and the rest is piled up in landfills, sinks into river beds or lies on roadsides around the world.

But Helms, a co-author of the Lawrence Berkeley National Lab, was part of the team that created a next-generation plastic called PDK (polydiketoenamine) that can be reduced back to its molecular parts and put back together if necessary.

“We are at a critical point where we need to think about the necessary infrastructure to modernize recycling facilities for future waste sorting and processing,” said Helms after the announcement of the new material. “If these facilities were designed to recycle or recycle PDK and related plastics, we could divert plastic more effectively from landfills and the oceans. This is an exciting time to think about how both materials and recycling facilities can be designed to make circular plastics possible. “

The building blocks of plastics – monomers – consist of elements such as carbon, hydrogen, oxygen, nitrogen, chlorine and sulfur. These monomers are linked by chemical bonds to form polymers that can be used in the formation of plastics that can be processed in various forms for many different uses.

The value of all those resources is lost in single-use applications, said Ryan of Sheffield. He calls it a “convenient truth” – the convenience and low cost of such products make them attractive to consumers without recognizing their inherent value and cost to the planet. Marketing strategies that claim that certain plastic products are “green” and biodegradable in order to attract well-meaning consumers are particularly important to him.

“Cynical ‘greenwash’ is the biggest problem for plastic sustainability,” he said. “So I was very interested in working on it with LaShanda and Thomas. I’ve known her since she got her Ph.D. Students.”

With innovation and collaboration as the pillars of the new centers they jointly lead – Korley’s US Department of Energy-backed CPI and Epps’ NSF-backed CHARM and GCR, Korley and Epps, Allan and Myra Ferguson Distinguished Professor of Chemical and Biomolecular Engineering, stand at the forefront of efforts to extend the life of petroleum and bioplastics and / or put them on a cycle that spans production, first use, and reconstitution forever.

Ryan said he was critical of a “circular economy”. He sees the value in recycling and upcycling and in the development of new materials, but none is a “silver bullet”. To address the plastics dilemma, the real value of plastics must be recognized.

“A solution is something America is not very good at – regulations, politics, and taxes,” he said. “There is no simple answer to the plastic problem. An unrestrained market will not offer it.

“With all these topics where science and technology and society overlap, the answer is always: It’s complicated.”

A more precise perspective, in Ryan’s view, is to see the plastic problem in the context of the climate change problem, without letting it distract.

“Climate change is an inconvenient truth and an invisible truth,” he said. “You can’t see what’s causing it, and you can’t see carbon dioxide in the atmosphere. They don’t associate driving to charge with climate change.

“You associate things with plastic waste – and that’s a convenient truth. We have no problem turning fossil fuels into plastics. But now we have to take care of this precious plastic. Don’t just throw it away. It’s just too cheap. Because of the pollution problem, we have to give it an artificially high price. “

Life cycle analysis data is key to making evidence-based decisions, Ryan said, and consumers and lawmakers cannot do this alone. You need experts who break down costs and benefits and explain the possibilities.

“It’s a lot more complex than most people can imagine,” he said.

The call to action is extensive.

“In order to achieve a more sustainable future, not only technological considerations, but also stock analysis, consumer behavior, geographic requirements, policy reforms, life cycle assessments, infrastructure alignment and supply chain partnerships are crucial,” the authors say.

Korley said she saw a growing passion for this daunting challenge.

“These initiatives generate excitement among our students – high schools, bachelors, and graduates, and our postdocs,” she said. “People are passionate about doing something to make the world a better place. And they can talk to their grandmother or their niece or nephew and explain why their work is important. ”


https: //www.mess.edu /Every day/2021 /July/plastic-pollution-lashanda-korley-thomas-epps-circular chemistry /


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