The integration of supramolecular interactions in macromolecular architectures offers the opportunity to design a great variety of self-healing polymers. Such systems are important in the context of the development of sustainable materials. Here, we will consider dynamic polymer networks, in which the chemical bonds between the polymer chains and the cross-links, occurring in conventional polymer networks, are replaced by electrostatic interactions. More precisely, n-butyl acrylate and 2-acrylamido-2-methyl-1-propanesulfonate anions (AMPS) were copolymerized while AMPS forms electrostatic interactions with butyltin oxo-cluster macrocations, [(BuSn)12O14(OH)6]2+ (Figure 1). For such materials, the description of the mechanical behavior requires the characteristic lifetime of the ionic interactions between the polymer chains and the hybrid cross-links to be determined. The segmental dynamics of the polymer chains and their interactions with the oxo-cluster macrocations will be investigated by 1H and 13C solid-state NMR. These motions will be probed over a time scale of tens of microseconds, but the dynamical processes involved will also be monitored over a longer time scale (1 ms – 1 s). The fraction of elastically active chain portions will be determined using 1H double-quantum experiments. The networks will be first studied in the molten state. In this case, temperature will allow to modulate the characteristic lifetime of the ionic interactions. In a second step, the same networks will be swollen in a good solvent (chloroform) and small amounts of another good solvent (DMSO), characterized by a higher dielectric permittivity ε, will be progressively added. This latter is another parameter allowing the characteristic lifetime of the ionic interactions to be varied. The evolution of the dynamical processes within the networks will be investigated as a function of the permittivity of the solvent mixture.

Dynamical processes in self-healing hybrid polymer networks: A solid-state NMR study

255th National Meeting (2018)

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