One-component Diels–Alder based polyurethanes: a unique way to self-heal. Issue 76 (12th October 2017)

• Record Type: Journal Article
• Authors: Willocq, B.; Khelifa, F.; Brancart, J.; Van Assche, G.; Dubois, Ph.; Raquez, J.-M.
• Is Part Of: RSC advances. Volume 7:Issue 76(2017)
• Page Start: 48047
• Page End: 48053
• Publication Date: 2017-10-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra09898g
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : In the present work, we synthesized one-component self-healing polyurethanes based on thermo-reversible furan/maleimide Diels–Alder reactions. Abstract : In this work, we introduce single-component self-healing polyurethanes based on reversible maleimide/furan Diels–Alder reactions with good physical integrity on healing. Diols bearing thermo-reversible furfuryl and maleimide moieties were synthesized by a four-step coupling strategy starting from commercially available 2, 2-bis(hydroxymethyl)propionic acid (bis-MPA) and thermo-responsive mono-alcohol (with furfuryl or maleimide functions). These diols were reacted in presence of 1, 6-hexamethylene diisocyanate and polypropylene glycol (PPG), in order to obtain amorphous polyurethanes with good chain mobility for the self-healing processes ( T g < RT). The cross-linking density, related to the healing process, could be readily tuned with the amount of thermo-responsive moieties as well as the PPG chain length. Swelling test and FTIR spectroscopy confirmed the formation of reversible networks. Qualitative micro-scratch test on thin films indicated tunable healing efficiencies based on the polyurethane composition as a function of the content, the chemical nature of the thermo-responsive moieties (reversible vs. irreversible), the PPG nature (hydroxyl or amino terminated) and chain length. This new structural concept is of great interest for thermally mendable, self-healing and adhesive polyurethanes.