Designer plastic can be recycled over and over again

An entirely new class of polymers that matches popular plastics’ thermal and mechanical properties but has the potential to be recycled and reused indefinitely has been developed by scientists in the US, China and Saudi Arabia.

Plastic pollution is one of the greatest environmental problems of our time, so creating polymers that can be turned back into their monomer building blocks for reuse is an important goal in materials science. But designing chemically recyclable plastics with desirable properties remains challenging.

Eugene Chen of Colorado State University, US, who led the study together with Laura Falivene from the King Abdullah University of Science and Technology in Saudi Arabia, explains that designing recyclable plastics that can compete with today’s leading materials means dealing with three apparently unbreakable trade-offs. ‘First, polymers that can be easily deconstructed typically don’t exhibit good properties. Second, highly crystalline materials tend to be brittle and easy to break, and third, to achieve high crystallinity for better mechanical properties, one must be able to precisely control the stereochemistry of the polymerisation.’