Healable Supramolecular Polyurethane Elastomers Possessing Pendant Bis-Aromatic Urea Recognition Units for Use in Repairable Coatings

This paper describes the synthesis, characterization, and supramolecular assembly of polyurethane elastomers. Bis-aromatic urea hydrogen-bonding motifs have been used to promote the self-assembly of the materials. The materials described comprise a soft block, namely, polytetramethylene ether glycol (PTMG), as a telechelic diol and hard crystalline domains that feature a bis-aromatic urea hydrogen bonding motif as a chain extender. Two diols were polymerized (one featuring the bis-aromatic urea hydrogen bonding motif) with a PTMG diisocyanate prepolymer to yield supramolecular polyurethanes with molecular weights ca. 185000 with polydispersities ca. 2.0. The mechanical properties and processing temperatures of the polyurethanes were shown to be tunable by controlling the feed ratio of the supramolecular chain extenders. These supramolecular polyurethanes were found to be healable in nature, offering a useful property for use of these elastomers in applications such as cable coatings.