Facile method towards mono-component polyurea composite coating with excellent mechanical properties and self-recovery ability

Polymeric coatings are often suffered from damages or irreversible deformations due to external impact during their server life, which may have adverse influences on the protection effect and aesthetics. Developing coatings that are mechanically robust and capable of recovering from deformation is urgently needed yet highly challenging. In this work, a class of mono-component polyurea/asphalt composite coatings with excellent mechanical properties and self-recovery ability is prepared through a facile method. The FTIR measurements indicate that the asphalt can react with polyurea, thus the interaction between asphalt and polyurea is enhanced. As a result, the mechanical stress and toughness of polyurea are increased. Moreover, the hydrogen bonds in the composite are identified by variable-temperature FTIR, which endows the composite coating with self-recovery ability as revealed by cyclic tensile tests. In addition, the thermal stability of polyurea is also improved after the inclusion of asphalt. Except for mechanically reinforcing, the incorporation of asphalt can also cut the cost as the mechanical properties of the composite coating are still better than pure polyurea even with 20 wt% asphalt. Moreover, the preparing process of the composite coating are quite facile, which hold great promise for large-scale production and application.