Influence of milled and acid-treated graphene oxide on the self-healing properties of graphene oxide reinforced polyurethane

The presence of microcracks in polymer coatings degrades the structural stability and lifespan of the protective layers. Enhancing the polymer-coated surfaces with self-healing properties has attracted considerable attention as it increases the reliability and lifespan of polymer systems. Herein, the strength and self-healing properties of polyurethane/graphene oxide (PU/GO) composite materials were improved using two GO treatments, referring to mechanical milling and chemical treatment with HF. When GO was surface treated for 5 h with an HF concentration of 40%, and PU/GO was heated 80 °C for 6–8 h, the over 80% healing efficiency can be obtained. The HF-treated GO-reinforced composites demonstrated high self-healing efficiency and remarkable mechanical performance, making them a promising self-healing material for protecting structural composites.