Pheno-recycle: phenolic resin finally recyclable
The result of a collaboration between researchers at the Charles Gerhardt Institute in Montpellier (ICGM) and Saint-Gobain, the Phéno-recycle project has led to the development of innovative processes for recycling phenolic resin. Until now, this has been one of the most solid types of waste in the chemical industry, destined for incineration or landfill. Supported by the Montpellier University Innovation Cluster in Montpellier, this virtuous partnership has been a resounding success.
They overcame an industrial impasse in less than three years. Working hand in hand, researchers at the Charles Gerhardt Institute in Montpellier (UM/ENSCM/CNRS) and Saint-Gobain have finally found a way to recycle phenolic resin, one of the most resistant and, until now, incompressible waste products in the chemical industry. And to cap off this first successful collaboration, the two partners, boosted by the resources of the University Innovation Cluster, have just filed a patent application.
Resistant thermosetting polymers
The story begins in 2021. Saint-Gobain approaches ICGM, which has expertise in the synthesis of phenolic resins with reduced environmental impact (formaldehyde-free) and "places particular importance on recycling and the more virtuous use of resources," emphasizes Vincent Ladmiral, director of research at the institute.
The industrial company Saint-Gobain uses these phenolic resins to design insulating materials, such as glass wool, and to manufacture abrasives, such as sandpaper.
“There is an issue surrounding these materials, which have a very long lifespan. They are thermosetting polymers, mainly consisting of carbon-carbon bonds, one of the strongest bonds in chemistry. They are extremely resistant to aging and chemical attacks. They also have high thermal stability. So, by definition, they are not easy to recycle," explains the researcher.
Small, reusable molecules
Specifically, through a thesis by the National Agency for Technological Research (ANRT) funded by Saint-Gobain in November 2022, the teams found a way to break down this resin into smaller, reusable molecules. After publishing an initial proof of concept in 2023, the team joined the "Companies & Campus"program, a tool developed as part of the University Innovation Cluster and designed to improve collaboration between public research and the business world.
Thanks to the €50,000 grant awarded by the University Innovation Hub's call for projects, the team was able to hire an additional engineer for 12 months. "We had the process, we already had promising recycling channels, but Companies&campus enabled us to further our understanding of the depolymerization mechanism and the structure of these oligomers," says Morgane Petit, head of the eco-processes and innovations for chemistry research and development group at Saint-Gobain Research Paris and coordinator of the sustainable chemistry network at Saint-Gobain.
“Winning on all fronts”
Through their research, scientists have succeeded in turning these resins into valuable residues. They have also managed to transform them into vitrimers, which have reversible properties. Invented in 2011, this new class of polymers consists of materials that can be melted and recycled at will... A godsend at a time when ecological transition is necessary. "It's a win-win situation, "says Vincent Ladmiral.
If Saint-Gobain implements this technology, it could enable these recycled materials to be used in the manufacture of new products, thereby helping to minimize the use of global resources. "We have high hopes for these materials, which could prevent the accumulation of thermosetting polymers that cannot be recycled. Until now, their end of life was limited to incineration or landfill... So from both a scientific and industrial point of view, this is a great success, " summarizes the ICGM researcher.