Synthesis and dynamics of metallo-supramolecular polymeric assemblies

Associating polymers, based on the dynamic metal-ligand (M-L) coordination, form an interesting class of materials because of the richness in their tunable properties and the design of various self-assembled materials. These adaptable systems have potential applications in various domains such as tissue engineering, coatings, adhesives or shock absorbers. Regardless of the final application, the possible exploitation of the transient nature hinges on the rheological behavior and resulting processability. In this respect, the design of responsive entangled supramolecular polymers is dependent on our fundamental understanding of their structure and dynamics in the melt state. This thesis addresses this grand challenge, and aims at a deeper understanding of how the combination of M-L interactions with entanglements impacts the structure, the relaxation dynamics and the mechanical properties of well-defined entangled metallo-supramolecular polymers over a wide timescale or temperature range. The structure-property relationships are established based on several experimental techniques (RAFT polymerization, shear and extensional rheology, DSC, DRS and X-ray scattering) combined with theoretical tube-based models (upgraded TMA). Results showed that the viscoelasticity of these systems are affected by both the disentanglement process of the polymers and the dissociation mechanism of the metal-ligand complexes. By altering the temperature, we systematically vary the relative importance of the M-L interactions, which allows us to determine their specific contribution to the viscoelastic properties. Through this systematic investigation, general guidelines are achieved to unambiguously control the design of supramolecular materials with specific rheological features that can be engineered over a wide window of mechanical properties.
(FSA - Sciences de l'ingénieur) -- UCL, 2018