Self-Assembly in Solution of a Reversible Comb-Shaped Supramolecular Polymer

We report a single-step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a comb-shaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration, or the temperature. Moreover, we demonstrate that the bulkiness of the arms has a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the number of polyisobutene arms can be controlled by simply mixing with a low-molar-mass bis-urea. This system thus combines a tunable structure and a dynamic backbone in solution. It is worth investigating its self-healing properties in bulk.