New Low-Heat Method Could Make Acrylic Plastics Endlessly Recyclable

A team at the University of Bath has developed a low‑temperature chemical process that breaks acrylic plastics back into their building blocks, potentially allowing them to be recycled again and again without losing quality.

Acrylic glass is everywhere: in car lights, phone screens, shop signs and protective barriers. But once it scratches, cracks or yellows, it usually heads for landfill or incineration.

Now chemists at the University of Bath in the UK say they have found a way to chemically recycle this common plastic at much lower temperatures and with more sustainable solvents, turning old acrylic back into material that is essentially as good as new.

The work, published in the journal Nature Communications, focuses on polymethyl methacrylate, or PMMA, the clear plastic sold under brand names such as Perspex and Plexiglas. About 3 million metric tons of PMMA are used worldwide each year in products that demand glass-like clarity.

With that scale of use, how to handle acrylic waste has become a pressing question.

One of the study leaders, Jon Husband, a research fellow at the university’s Institute of Sustainability and Climate Change (ISCC), noted the status quo is not working.

“With current methods for recycling both energy intensive and inefficient, the demand for cleaner, more efficient recycling technologies has never been greater,” he said in a news release.

Most plastics recycling today is mechanical. Old parts are shredded or melted, then remolded into new items. For PMMA, that approach comes with a major trade-off.

In the press materials, the Bath team described what they call the Perspex problem: mechanical recycling is the most common recycling method, which can involve shredding or melting the plastic to reform pellets for new uses. However, this leads to discoloration and a gradual decline in quality, meaning the recycled material can no longer be used for glass-like applications such as screens or spectacles. That pushes recycled acrylic into lower-value uses and, eventually, disposal.

To get around that, industry has turned to a more advanced option known as pyrolysis. In that process, PMMA is heated to roughly 350-400 degrees Celsius to break it back down into its original building blocks, called monomers, which can then be used to make fresh, high-quality plastic.

But those high temperatures require a lot of energy, and the process can be easily contaminated by traces of other plastics mixed in with the waste stream, making it harder to recover pure material.

The Bath team’s method aims to keep the benefits of chemical recycling while cutting the environmental and energy costs.

Their process uses ultraviolet light under oxygen-free conditions to trigger a reaction that essentially unzips the long PMMA chains back into their monomer units. Crucially, this chemistry runs at 120-180 degrees Celsius, far below the temperatures needed for conventional pyrolysis.

Lower heat means less energy use and potentially lower operating costs, which are key barriers to scaling up advanced recycling technologies. The team also designed the system to work with more sustainable solvents, rather than the chlorinated solvents used in a recent, related PMMA recycling discovery from researchers at ETH Zurich.

According to the Bath group, the new approach converts more than 95% of the plastic and yields over 70% of the original monomer. That monomer can then be purified and repolymerized into new PMMA with properties comparable to virgin material.

In other words, instead of downgrading old acrylic into cloudy, low-grade products, the process is designed to keep it in a high-value loop.

Simon Freakley, an ISCC co-investigator and a senior lecturer in the Department of Chemistry at the University of Bath, who co-led the study, noted the goal is to move beyond recycling that only delays disposal.

“This method allows us to recover high-quality monomers from used PMMA, offering a clear pathway toward genuine circularity in acrylic materials,” he said in the news release.

The idea of circularity — keeping materials in use at their highest value for as long as possible — has become a central theme in efforts to reduce plastic waste. Traditional recycling often falls short because each cycle degrades the material. Chemical routes like the one from Bath aim to reset the clock by returning plastics to their original ingredients.

Right now, the team can recycle only a few grams of real plastic waste at a time in the lab. Their next steps include improving the efficiency of the reaction and scaling it up so it can handle larger volumes and more complex waste streams, such as mixed or colored acrylic from consumer products.

If the method can be industrialized, it could offer manufacturers a way to design acrylic products with their end of life in mind, knowing that the material can be broken down and rebuilt many times over without losing clarity or strength.

More broadly, the work adds to a growing push in chemistry to redesign plastics and their life cycles. While no single technology will solve the global plastics problem, advances like this one suggest that some of the most widely used materials might one day be part of a truly circular economy, rather than a one-way trip from factory to landfill.