A team from the University of Bath has developed a chemical recycling method for PMMA that operates at lower temperatures and allows for the recovery of high-purity monomer with over 95% efficiency, opening new possibilities for acrylic circularity.
PMMA (better known as acrylic) is one of the most widely used plastic materials worldwide, and while mechanical recycling of this material has increased in recent years, a team of researchers from the University of Bath in the UK has developed a new method for its chemical recycling.
As the team explained in a publication in Nature Communications, unlike conventional mechanical recycling, the new method uses lower temperatures and sustainable solvents, ensuring that the recovered material retains its original quality.
This development has potentially significant impacts on the global economy, given that an estimated 3 million tons of PMMA are used annually worldwide in the development of components for various industries.
The research was led by Drs. Jon Husband and Simon Freakley of the Institute for Sustainability and Climate Change (ISCC) at the University of Bath, and co-authored by Professor Matthew Davidson, Director of the Innovation Centre for Applied Sustainable Technologies (iCAST).
The Challenge of Recycling Acrylic
In optical applications, such as display cases, lighting fixtures, and screens, PMMA requires high transparency and stability. However, mechanical recycling causes discoloration and molecular degradation, limiting its reuse in high-value products.
Faced with this limitation, the industry has turned to pyrolysis, a thermal process that heats the material to between 350 and 400 °C to depolymerize it and recover the monomer. The problem is twofold:
High energy consumption.
Sensitivity to contaminants and mixtures with other polymers.
This reduces the economic and environmental viability of the process.
Chemical Recycling with UV Light: Lower Temperature, Greater Efficiency
The Bath team’s proposal introduces an innovative route based on ultraviolet light in oxygen-free conditions, which allows PMMA to be broken down into its original monomers at significantly lower temperatures: between 120 and 180 °C.
This temperature reduction represents a substantial improvement in terms of energy efficiency and carbon footprint.
Furthermore, the process uses more sustainable solvents, expanding its potential for industrial implementation compared to other research that relies on chlorinated solvents.
According to Dr. Jon Husband, a researcher at the Institute for Sustainability and Climate Change (ISCC):
“Current recycling methods are energy-intensive and inefficient. There is an urgent demand for cleaner and more efficient technologies. This work directly addresses both problems.”
Yields exceeding 95%: Towards true circularity
One of the most relevant findings of the study is its technical performance:
Over 95% plastic conversion.
Over 70% monomer recovery, ready for purification and repolymerization.
In practical terms, this means that recycled PMMA can be remanufactured with properties virtually equivalent to virgin material—a key step toward achieving true circularity in high-performance plastics.
Dr. Simon Freakley emphasized:
“Chemical recycling allows us to transform waste into new, pristine materials, instead of low-value, degraded products.”