Mike Shaver is currently Professor of Polymer Science at the University of Manchester in the School of Materials. In this article Mike explores how we should be viewing the use of plastic and also how we can avoid the potential environmental problems from plastic alternatives.

• Sustainable alternatives to plastic need thoughtful analysis of the whole material life cycle to address present and future challenges.
• Urgent technology development is needed as well as the infrastructure for companies or public authorities to profit from and properly collect ‘end-of-life’ products and materials.
• Policy decisions on the future of plastics need to be joined up with the science that underpins our understanding.

As a society we have a problem – like it or not, we’re addicted to plastic. And it’s not hard to understand why. Plastics are miraculous materials – a remarkable 20th century invention which has changed our world. From Lego bricks to heart valves, from toothbrushes to computers, plastic has countless practical uses. But what was once hailed as a wonder material is now widely viewed as an environmental scourge of the planet. So how should we view this most astonishing and prolific material and more importantly, how can we solve the problem we’ve created?

Plastics have provided massive energy savings compared to the many materials it has replaced during the last 50 years: lighter cars that burn less fuel, food that lasts longer on shop shelves, packaging that weighs less, windows that better insulate your home – plastics have revolutionised supply chains across practically all industries. And yet it’s the poster child for the wasteful take-make-dispose linear economy. A lot of that is to do with the fact that every single piece of plastic that has ever been produced is either still with us somewhere, in your kitchen cupboard, in a landfill site or floating somewhere in the oceans. Or, if it has been incinerated, it’s released its entrapped carbon as the greenhouse gas, CO2.

Thoughtful sustainability?

So how might we design alternative materials that fit our lifestyles, economy, and needs without such environmental damage? And how can we create a regulatory environment that incentivises genuinely sustainable innovation and avoids putting barriers in the way of getting solutions rolled out?

Sustainable advanced materials need thoughtful analysis of the whole material life cycle to address present and future challenges. We need to be clear on how the product is being made, the cost of that process, what the final product is actually going to be used for, and most pressingly, what will happen to the product when it’s reached the end of its ‘life’; things that perhaps weren’t given much thought, at the start of the 20th century, when plastics were the ‘advanced materials’ of their time.

BBC Television’s Blue Planet II highlighted the problem of single-use plastic packaging, but when people talk of wanting a ‘plastic ban’ it’s important to realise that plastics in particular are pervasive and impact every aspect of our lives, because of their incredible versatility. Trying to find a replacement material that can do all the same things as plastic is impossible – there is no one silver bullet that can solve our plastic problems – and solutions often do more hidden environmental damage than good. Blanket bans are foolish and overly simplistic – microbeads in personal care products are fine if they degrade – but degradation needs to be proven in real environments. Demonstrating that a material can degrade in a controlled solution isn’t the same as showing it can do so in a fatberg-infested sewer.

Solutions and quick wins

And so, the solutions must be product specific. What is the best solution for all the different waste challenges we face? While it is perilous to replace all of our plastics with biodegradable alternatives due to the unknown ecological risks and loss of arable land, there are some quick wins.

Plastic films that are challenging to recycle, such as those found at the top of meat packaging or fruit punnets, are an excellent target for biodegradable plastics, as are many sources of microplastics found in cosmetics or from washing textiles. Conversely, hard plastic containers can often be recycled well, and so we should focus here on smartening our recycling infrastructure and encouraging reuse. The key is to efficiently make this waste worth something – to give it a value, regardless of its origin, which means that different solutions are needed for each plastic challenge. The plastic legacy isn’t going to disappear from a whole suite of alternatives, but from a combined approach of innovation in advanced materials alongside innovation in how we recycle and manage our waste.

Recycling rates in the UK and the rest of the world are far short of where they could, and I’d argue, should be. This individual and infrastructural laziness has been compounded by China’s decision to stop accepting all the contaminated recyclable materials that most of the Western world has been sending them. This is forcing us to finally fix these problems ourselves and will hopefully lead to innovation, both in policy and in solutions, such as the development of optical sorting, where cameras or lasers sort our solid waste matter for us.

We must urgently develop technology and infrastructure for companies or public authorities to profit from and properly collect ‘end-of-life’ products and materials. Simple policy interventions can help with that, whether it’s ensuring local authorities can all recycle the same materials, or simply that they all use the same colours for recycling bins.

Science and industry

A big part of getting to these solutions, is the problem of scale. There are lots of inventions and processes that are being done on a laboratory scale, but the problem of plastics is huge. And while there are companies interested in these potential solutions, scaling up from a lab experiment to a marketable product is a massive challenge.

The University of Manchester is quite progressive in its approach to bridging this gap – for example, the Graphene Engineering Innovation Centre (GEIC) is bringing industry into the University to work closely with academics to help scale up pilot projects to market, while the Royce Institute is bridging the materials science gap in a similar way. This leadership is built on exceptional research efforts, including Dr Arthur Garforth’s development of catalysts for waste valorisation, the Sustainable Consumption Institute’s recognition of the societal factors that impact decision making around plastic packaging use or work in our own group on fast-degradable polymers using designer monomers – new molecules that work together to mimic polystyrene packaging.

A more collaborative future

So where do we go from here? We clearly need policy decisions to be joined up with the science that underpins our understanding. Simplifying our recycling systems will greatly improve personal compliance. We need experts who can work comfortably across disciplines, versed not only in materials science decisions, but also in the social science understanding of how the complex industry supply chain and public consumer will interact with these materials. The RE3 research project led by The University of Manchester brings together manufacturing, social, and material scientists, and several other academic and industrial partners. Among other things, this project is looking at demonstrating new methods for recycling soft and mixed plastics and non-plastic films, and creating smart circular economies that allow users to take ownership of and reduce plastic waste.

We need a unified understanding of what terms mean – compostable does not mean biodegradable, and biodegradable in a lab does not mean biodegradable in a sewer or the ocean – preferably underpinned by proper metrics. This will help shape a future where the best academic research is developed in collaboration with industry partners from across the supply chain, underpinned by funding from government to translate new ideas, like The University of Manchester work I’ve described here, into scalable solutions.

Most importantly, all developments should be based on rigorous and robust science, utterly transparent and accountable, and follow through any new solutions to their own ‘end-of-life’, otherwise we risk creating new problems for future generations. Academics, industry, waste managers and government regulators must start pulling in the same direction to solve this grand challenge.

And if there’s one thing we can’t waste, it’s time.

• This article was originally published in ‘On Materials,’ a collection of essays aimed at the advanced materials community in Greater Manchester and across the UK. You can read the full publication here, or in shorthand here.