(New) materials with optimized properties
The infinite possibilities opened by recent chemistry and better controlled processes make it all the more necessary to understand the structure/properties relationships, which can then intervene in an efficient way from the design of materials. The team is also interested, in collaboration with chemists, in the properties of different systems called "supramolecular" or "self-associative". This activity was consolidated by the MdC recruitment in 2016 of Guilhem Baeza. The targeted properties were adhesion (ANR Supradhesion), self-repair (ANR Arcade), or an optimized viscoelastic mechanical response (R. Gallu's thesis, 2018, coll. IMP/Eiffage/Soprema on bituminous admixtures). In all these projects, the team had the task to understand the link between local properties (dynamic, physicochemical...), multiscale microstructure and macroscopic properties of these systems through the use of many experimental characterization techniques (AFM, SAXS, SEM, TEM, DMA, rheology...), and sometimes the development of theoretical models.
Représentation schématique d’un copolymère segmenté
The PVMH team is also recognized for its expertise in the field of polymer matrix nanocomposites. Among the different materials studied, we can mention latexes reinforced by LDH nanoplatelets encapsulated by RAFT polymerization in emulsion in which the role of interactions and chemical composition on the formation of a mixed LDH/Macroraft percolating structure was explained, this structure being essential in the level of reinforcement observed. Moreover, the study of silica/SBR nanocomposites showed that the viscoelastic properties at small and large deformation could be decoupled by adjusting the amount of polypropylene glycol oligomer used as a coating agent.