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Role of Diisocyanate Structure on Self‐Healing and Anticorrosion Properties of Waterborne Polyurethane Coatings
Author(s) -
Yu Changjiang,
Salzano de Luna Martina,
Russo Andrea,
Adamiano Ignazio,
Scherillo Fabio,
Wang Zhanhua,
Zhang Xi,
Xia Hesheng,
Lavorgna Marino
Publication year - 2021
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.202100117
Subject(s) - isophorone diisocyanate , hexamethylene diisocyanate , polyurethane , materials science , crystallinity , coating , fourier transform infrared spectroscopy , polyurea , chemical engineering , composite material , polymer chemistry , engineering
Organic coatings are extensively investigated as possible solution to prevent or at least retard the occurring of corrosion processes on metal surfaces. Their actual breakthrough is still hampered by the risk of barrier properties loss because of local failure of the coating integrity. To address this issue, self‐healing coatings, which are intrinsically able to recover from damages upon exposure to external stimuli, are currently gaining increasing attention. Herein, waterborne polyurethanes (PU) are synthesized, and a Diels–Alder adduct is added into the polymeric backbone to endow the material with self‐healing functionality. The effect of different diisocyanate in PU synthesis is explored, namely isophorone diisocyanate, 4,4′‐dicyclohexylmethane diisocyanate (HMDI), and hexamethylene diisocyanate. The obtained results highlight the key role of the interactions among soft and hard segments in ultimately defining the coating performances. Actually, the combination of Fourier transform infrared spectroscopy, atomic force microscopy and X‐ray diffration analysis reveals that the HMDI‐based PU have showed the best balance in terms of H‐bonding strength among hard segments and crystallinity degree in the soft ones. This allows to reach a good compromise in terms of mechanical resistance, anticorrosion properties, and self‐healing ability.