Despite scientific advances in the area of plastics sustainability, the pollution that results from its use remains a serious problem. New research from the University of Akron (UA) offers a promising solution with the potential for acceptance by the rubber, tire, automobile and electronics industries.

The research, led by Dr. Junpeng Wang, assistant professor in UA's School of Polymer Science and Polymer Engineering, addresses the problem of synthetic polymers, used in almost all aspects of daily life, including rubber and plastics. Their widespread adoption resulted from their excellent stability and versatile mechanical properties, one of those being durability, the effects of which are at the heart of the plastics pollution problem that impacts the land and the oceans.

Another consideration is the fact that the vast majority (over 90%) of synthetic polymers are produced from petroleum and coal which are finite resources. Future production requires the recycling and reuse of the materials.

Recyclable polymers have, for the most part, lacked the thermal stability and high performance mechanical properties of synthetics. Wang and his team have developed unique recyclable materials that exhibit superior thermal stability and mechanical versatility.

"We are particularly interested in chemically recyclable polymers that can be broken down into the constituents (monomers) from which they are made," says Wang. "The recycled monomers can be reused to produce the polymers, allowing for a circular use of materials, which not only helps to preserve the finite natural resources used in plastics production, but also addresses the issue of unwanted end-of-life accumulation of plastic objects."

Source: University of Akron

The team is focused on breaking down the polymers into their constituent parts. When the catalyst for depolymerization is removed or absent, the polymers are highly stable and their properties can be adjusted to make them suitable for different applications.

Through careful computational calculation, the researchers identified a targeting monomer, the key in the design of chemically recyclable polymers. Using readily available starting materials, they prepared the monomer and polymers through chemical synthesis.

"The chemically recyclable polymers we developed show excellent thermal stability and robust mechanical properties and can be used to prepare both rubber and plastics," says Wang. "We expect this material to be an attractive candidate to replace current polymers. Our molecular design is guided by computation, highlighting the transformational power of integrating computation and experimental work. Compared to other recyclable polymers that have been demonstrated, the new polymers we demonstrate show much better stability and more versatile mechanical properties. When a catalyst is added, the polymer can be degraded into the constituent monomer for recycling."

The UA researchers will expand the scope of their work to develop carbon-fiber reinforced polymer composites, and analyze economic performance of this industrial process as well as the life-cycle for commercialization of the polymers.

The current research is published in Nature Chemistry.