Modeling the viscoelastic properties of unentangled sticky polymer chains

Inspired by nature, supramolecular chemistry has been developed to form associating blocks with diverse properties. Among several non-covalent interactions that can be used in the supramolecular chemistry, the highly-directional metal-ligand (M-L) coordinations are attracting high attentions as they can be finely tailored with the choice of ion and ligand types. The properties of supramolecular junctions were first used to assemble small chemical entities or oligomers, while more recently they have been used with polymers of higher molecular weight. They are later on incorporated into polymers with higher molecular weight. With both the characterisations of M-L coordination and polymer chains, the features of the metallo-supramolecular polymers can be dynamically tuned based on several approaches. The resulting metallo-supramolecular polymers can self-assemble into large architectures. In specific cases, the metal-ligand complexes can phase separate and lead to well-organized nanostructures, which can reinforce the sample. This gives the polymeric materials a wider range of properties that can be adjusted during the processing. As a consequence, the metallo-supramolecular polymers can be more easily processed with external stimuli such as temperature, irradiation, shear or elongation. The dynamics of these metallo-supramolecular polymers are measured by rheometer. While today, there is a good understanding of the viscoelastic properties of conventional polymer melts, the response of metallo-supramolecular polymers have not yet been well understood. In the framework of this master thesis, the material studied is a linear poly(n-butyl acrylate)-co-poly(terpyrindine acrylate), bearing with terpyiridine ligands along its backbone. A stoichiometric amount of ions are then added to the system to create a supramolecular network. The aim of the project is to develop a series of models to analyze the dynamic behavior of the metallo-supramolecular polymers. Starting from the normal Rouse and sticky Rouse model, we then explore and discuss different ways to account for the effect of the metal ions on the properties of these samples, with the aim of providing guidelines to develop new associating polymers.