The preparation and study of functionalized graphene oxide/self-healing waterborne polyurethane composites

In this study, silane coupling agent KH560-FA containing furan groups was synthesized to modify the surface of graphene oxide, and maleimide group-capped waterborne polyurethane was synthesized at the same time. A self-healing material with a microcrosslinking network structure based on polymer/modified graphene oxide was synthesized by Diels–Alder (DA) reaction. The materials obtained can control the formation and fracture of DA chemical bonds under thermal stimulation and repair the damage macroscopically. With the addition of modified graphene oxide from 0 wt% to 0.4 wt%, the tensile strength of the material increased from 3.59 MPa to 15.27 MPa, the repair efficiency reached a maximum of 89.19%, the water contact angle increased from 61° to 77°, and the water absorption decreased from 10.52% to 3.40%. The addition of modified graphene oxide significantly improved the hydrophobicity and mechanical properties of the material. When the addition of KH560-FA-GO was 0.4 wt%, the corrosion resistance of the coating prepared by the emulsion was remarkably improved in deionized water, 5% sodium chloride solution, and 5% sulfuric acid solution. It showed the application potential of materials in the field of coatings.