Synthesis of robust and self-healing polyurethane/halloysite coating via in-situ polymerization

Due to the outstanding properties comprised of thermal, anti-corrosion and excellent processing properties, the polyurethane coating has received attention from many researchers. However, absence of self-healing capacity limited their applications. In the present work, a self-healing polyurethane (PU) was developed for protective coating via Diels–Alder reaction. Moreover, incorporation of Halloysite nanotubes (HNTs) by in situ polymerization method in the PU enhances the mechanical properties. The macro- and micro-mechanical properties of materials were investigated by tensile and nanoindentation measurement, these results show the composites displayed higher tensile strength (34.2 MPa) and hardness (5.13 MPa) in comparison with pure PU (22.9 MPa and 4.24 MPa). The tensile and POM results indicated that the PU and composites have excellent self-healing property. The simulative salt spray tests indicated the coating possessed an excellent corrosion protection property. Therefore, this work is promising for the self-healing ability protective polymer coating.