Tribological performances of polyurethane or phenol-formaldehyde resin solid self-lubricating composites doped with PTFE and Mg-Al LDH

Frictional wear has always been one of the main causes of energy consumption and material loss, and selflubrication is considered to be the most effective way to control or reduce frictional wear. However, with the increasing demand for lubrication performance in industrial production, traditional lubrication additives can no longer meet the demand. Polymers have low friction, self-lubricating properties, and therefore play a key role in a multitude of industries. Due to its low friction coefficient and self-lubricating performance, it can effectively reduce friction resistance and energy consumption under no or little lubrication conditions. This property makes the polymer perform well in environments where dry friction is required, especially for components like gears, bearings, and piston rings. Polytetrafluoroethylene (PTFE) and magnesium aluminum hydrotalcite (Mg-Al LDH) have better self-lubricating properties. In this study, polyurethane (PU) and phenol-formaldehyde resin (PF) were used as substrates, PTFE and various concentrations of Mg-Al LDH were doped to enhance the frictional properties and wear resistance of solid self-lubricating composites. The results indicate that PU-based self-lubricating composites with 1 wt% Mg-Al LDH exhibit optimal performance, achieving an average friction coefficient of 0.12358 and a wear loss of 0.00057 g. PF-based self-lubricating composites containing 2 wt% Mg-Al LDH demonstrate the best performance within their group, with an average friction coefficient of 0.14461 and a wear loss of 0.00183 g. These findings highlight the influence of Mg-Al LDH content on enhancing the frictional behavior and wear resistance of polymer composites.