Synthesis melamine-formaldehyde microcapsules containing paraffin to improve the tribological properties of self-lubricating fabric liner composites

Hence, melamine-formaldehyde microcapsules containing paraffin wax (MF@PW) with lubrication and phase change functions were prepared for enhancing the tribological properties of self-lubricating fabric liner. The particle size of MF@PW is between 3 and 5 mu m, and the shell thickness of melamine-formaldehyde (MF) is about 70 nm. The dispersion and binding properties of MF@PW in phenol-formaldehyde (PF) were regulated by in situ polymerization (PF-MF@PW), which guarantees good mechanical properties of composites. The tribological properties of PF-MF@PW-coating and PF-MF@PW-liner were systematically studied. The results show that 6 wt % MF@PW can reduce the friction coefficient (COF) of PF-coating from 0.549 to 0.065, and that of the corresponding liner reduces from 0.081 to 0.066. The friction mechanism shows that under the combined action of force and friction heat, the microcapsules break and releases PW at the friction interface, PW provides lubrication while inhibiting the adhesion of PF abrasive chips and the large-area peeling of PTFE. At the same time, the coordinated action of PW and PTFE can promote the formation of transfer films with higher surface quality. This work provides a new modification method of self-lubricating liners, which is beneficial to improve the tribological properties of the self-lubricating fabric liners.