Enhancement of polyurea grease performance through graphene oxide-functionalized polyurea thickeners: A novel hydrogen-bond network approach

In conventional grease formulations, thickeners and additives are added as distinct components. This study introduces a method that integrates graphene oxide (GO) functionalized polyurea thickeners, creating a unified structure of polyurea and GO. The impact of GO functionalized polyurea on the rheological and lubrication performance of polyurea grease was investigated. Results showed that the polyurea modifies GO by covalent bonds and forms a hydrogen bond network. The GO modified polyurea reduced the yield stress and improved the flowability of the polyurea grease. The GO modified polyurea enhanced the tribological performance of polyurea grease because of the collaboration effect of tribo-chemical film and graphene boundary film. This study emerges as a viable strategy to improve the performance of polyurea grease.