Details

Autor(en) / Beteiligte

• Yu, Changjiang
• Salzano de Luna, Martina
• Russo, Andrea
• Adamiano, Ignazio
• Scherillo, Fabio
• Wang, Zhanhua
• Zhang, Xi
• Xia, Hesheng
• Lavorgna, Marino

Titel

Role of Diisocyanate Structure on Self‐Healing and Anticorrosion Properties of Waterborne Polyurethane Coatings

Ist Teil von

• Advanced materials interfaces, 2021-05, Vol.8 (10), p.n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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. Tailoring the polyurethane chemistry is essential to obtain protective coatings with reliable and durable anticorrosion properties. The addition of a Diels–Alder adduct in the polyurethane backbone also allows to impart self‐healing ability. To this aim, the proper choice of the diisocyanate molecule is crucial to determine the proper phase morphology and molecular mobility, ultimately dictating the material performances.