Hydrogen-bonding network boosts the anti-wear performance of Ca/Al layered double hydroxide/polytetrafluoroethylene composite

Polytetrafluoroethylene (PTFE) molding is regarded as a promising component for shaft sealing owing to its excellent insulation and lubricity properties. However, the low anti-wear performance derived from the large creep of the PTFE polymer limits its highly stable operation. Herein, two-dimensional calcium aluminum layered double hydroxides (Ca/Al-LDHs) are introduced as solid lubricants to enhance the anti-wear property of PTFE-based molding to yield LDH-PTFE-x% (where x denotes the mass ratio of Ca/Al-LDHs). The wearable performance of LDH-PTFE-8% is 3.4 times greater than that of pure PTFE-based molding, while maintaining excellent mechanical properties. The high unctuosity of Ca/Al-LDHs, in addition to the hydrogen-bonding intermolecular interaction between the OH- anions of Ca/Al-LDHs and -F groups in PTFE, results in the formation of a protective transfer film containing Ca/Al-LDHs during the friction process to enhance the wear resistance of LDHPTFE molding.