New bio-sourced monomer based on sesamol for copolymerization with Elium® resins and its depolymerization behavior

Following the circular plastic economy, environmental awareness, and more stringent environmental regulations, thermoplastic resins are experiencing renewed interest. Even though thermoplastic resins for high-performance applications are a major breakthrough towards sustainable materials due to their high recycling potential, the sourcing of the material is also a critical point to investigate. In this regard, both the sourcing and the recyclability properties must grow together as the ultimate goal for sustainable materials. In the present investigation, a novel bio-based monomer derived from sesame (Sesamum indicium L.) has been integrated into Elium® thermoplastic resins in order to increase the amount of bio-based content in the final material. It was expected that linear copolymers with high glass transition temperatures would be produced. Nevertheless, the thermoplastic chemistry of Elium® has been modified by adding its sesamol methacrylate counterpart. The polymer network morphology was established by studying the relationship between crosslinking density and swelling properties. Furthermore, significant enhancements were achieved by adding sesamol methacrylate (SM) to Elium® thermoplastic resins: i) the curing time decreased from 10 min. to 5 min., and ii) the thermo-mechanical properties exceeded the initial performances of Elium® thermoplastic. Additional research was carried out to assess the recycling potential of these bio-based copolymers through monomer recovery, also known as depolymerization. In parallel to PMMA unzipping depolymerization, it has been demonstrated that materials made from sesamol methacrylate can also be depolymerized, leading to regenerated sesamol methacrylate monomers.