Scaling Synthesis Of Glowing Polymers

Chemically recyclable fluorescent polyesters via the ring-opening copolymerization of epoxides and anhydrides

Taylor B. Young, Owaen G. Guppy, Alysia J. Draper, Joshua M. Whitington, Benson M. Kariuki, Alison Paul, Mark Eaton, Simon J. A. Pope and Benjamin D. Ward

School of Chemistry, Cardiff University

Polym. Chem., 2023, 14, 2478-2484

https://doi.org/10.1039/D3PY00209H

The exponential growth in plastic production and consumption over the last few decades has led to severe environmental concerns. Recent research has focused on developing polymers that can be chemically recycled to address this challenge. Traditional plastic recycling methods are often limited by the presence of colourants, which cannot be removed by reprocessing and result in recycled plastic retaining the colour of the original material.

Reactor-Ready being used to synthesise glowing polymers at Cardiff University

Researchers at Cardiff University have developed single-component, coloured polymers that can be recycled back to their parent acid/alcohol and remade into colourless polymer. The paper explores the use of chromophore-containing monomers in epoxide-anhydride ring-opening copolymerisation (ROCOP) to create coloured polymers.

This method results in covalent bonding of the dye within the polymer, providing highly coloured materials with little change in properties from the base polymer. Only dopant levels of chromophore are needed.

ChemDraw Image showing synthesis of glowing polymers

They found that the addition of epoxide-functionalised chromophores induces colouration and luminescence of the polymers. The doped polymers can be depolymerised, the chromophore removed, and the base monomers remade and repolymerised to give colour-free polymer.

Reactor-Ready set up in Ben Ward's lab sat next to Huber minichiller

The polymerisation reactions were performed in a Radleys 2-litre Reactor-Ready Jacketed Lab Reactor, with overhead stirring from a Hei-TORQUE stirrer and temperature control from a Huber Ministat. The ability to perform these reactions on a larger scale using the Reactor-Ready enabled the group to synthesise 280-320 g of material in one reaction. The researchers noted that large-scale homopolymerisations of epoxides have the potential to be exothermic. However, an external PT1000 temperature probe was used in conjunction with the Huber Ministat which gave direct reaction temperature control – meaning exotherms could be rapidly detected and the reaction cooled.

The ability to take a coloured polymer and chemically recycle it to afford pure white polymer solves an important challenge in the plastics recycling industry. The strategy should be amenable to a wide range of dopants that can introduce different functionalities to impart bespoke physical and chemical properties upon the polymer. This research has the potential to transform the way we produce and consume polymers and create a more sustainable future for our planet.

To find out more about how the Reactor-Ready has been a “game changer” for Dr Ward’s research group, check out our video ‘Scaling up sustainable polymer synthesis in Reactor-Ready’.

Close up of 2000 mL Reactor-Ready with orange liquid