Solène carried out her research in the P3R team at the Softmat laboratory, in close collaboration with Specific Polymers company.
On 22nd of November, she defended her thesis entitled: “Synthesis and characterization of biobased disulfide vitrimers for industrial applications”
Today, the development of new industrial strategies geared towards more eco-responsible processes is essential to improving our society’s environmental footprint. In this context, the aim of her project was to develop, synthesise and characterise new biobased and recyclable materials with a view to replacing certain conventional materials derived from the petroleum industry and used in numerous industrial applications.
To this end, a new family of polymers, known as vitrimers, has attracted her attention. Vitrimers are dynamically polymer networks that differ from conventional polymer classes such as thermoplastics and thermosets. The unique dynamic character of these new materials is linked to the presence of reversible cross-linking points that induce mobility of macromolecular chains under precise conditions of use. This network, whose topology can be rearranged by exchange reactions via thermal activation, has the ability to maintain its network integrity. In this way, the number of bonds remains constant during rearrangement, making it possible to combine structural stability with adaptive flexibility, opening up new perspectives. In particular, this time- and temperature-dependent dynamic behavior enables these materials to be reshaped and recycled at the end of their life cycle, thus promoting the reuse of damaged materials. Vitrimers based on disulfide exchange are well represented in the literature, and their interesting mechanical properties have proved highly advantageous.
The main objective of her work was therefore to incorporate recyclable properties into biosourced epoxy resins by introducing dynamic disulfide bonds.
Initially, the preparation of these innovative materials was based on the design and optimisation of epoxy/amine disulfide vitrimer systems.
Secondly, these new dynamic networks were characterised by thermomechanical analysis and compared to traditional petro-sourced networks reported in the literature.
Also, a complementary kinetic study based on model compounds highlighted the catalytic effect of amines on the disulfide exchange reactions involved in our epoxy/amine networks.
Besides the significant influence of the chemical environment (aromatic/aliphatic, nucleophilic), structure/property relationships have also been demonstrated through this research, extending the knowledge based on the control of dynamic properties within these disulfide vitrimers.
Finally, taking advantage of the results obtained, a new closed-loop chemical recycling method was evaluated with a view to placing synthesised vitrimers in a circular economy, a concept widely used to improve current industrial processes.
Highlights of the thesis:
- An article reporting on this work has been selected for inclusion in the “Emerging Investigators series” of the journal Polymer Chemistry;
- Solène won an award for her oral presentation at the Polymers & Composites 2023 conference.
Many congratulations to Solène for the quality of her work and her involvement in the life of the lab!
