Double dynamic self-healing polymers: supramolecular and covalent dynamic polymers based on the bis-iminocarbohydrazide motif

Self-healing polymers are a class of functional polymers that, by the virtue of the presence of certain dynamic chemical linkages, may undergo self-repair at a mechanically cut surface. Herein we report the synthesis of a self-healing polymer giving access to double dynamicity within the polymer network by making use simultaneously of reversible covalent bonds and dynamic non-covalent hydrogen bonding interactions. These features are provided, respectively, by doubly dynamic cassettes comprising chemically reversible imine linkages and multiply hydrogen-bonded urea groups, connected by a siloxane-based backbone that imparts softness to the material. Such a system can be envisaged to give access to a broad spectrum of functional materials, which can be tuned by convenient modulation of the structural motifs of the polymer. (C) 2013 Society of Chemical Industry