Ultra-low Friction and Wear of Phenolic Composites Reinforced with Halloysite Nanotubes

To decrease the number of interfaces and facilitate the designing of polymer tribo-composites, traditional fillers in phenol-formaldehyde resins (PF) with multiple dimensions and components were replaced with halloysite nanotubes (HNTs). The composites’ tribological performance were studied under a wide range of pv (pressure × speed) conditions. It is revealed that the single incorporation of HNTs significantly lower the friction and wear of PF. In particular, the composites exhibit ultra-low friction and wear under high pv conditions. Mechanism analyses demonstrate that the composites’ tribofilms show distinctly different nanostructures depending on the pv conditions, which was studied thoroughly through morphological and chemical characterizations. Findings of the present work provide new strategies for formulating tribo-composites for applications subjected to harsh sliding conditions.