Preparation of ionic liquid@SiO2 nanocapsules for improving self-lubricating performance of PA6 composites

A novel high temperature resistance ionic liquid@SiO2 (IL@SiO2) nanocapsules were successfully prepared in order to meet the high temperature processing requirement. The average diameter and the loading capacity of as-obtained IL@SiO2 nanocapsules were about 420 nm and 44.7 wt% respectively. The IL@SiO2 nanocapsules showed excellent thermal stability with a 340 °C initial thermal degradation temperature. The frictional and wear properties of PA6 composites containing IL@SiO2 nanocapsules under different friction temperature were studied systemically. Self-lubricating PA6 composites with 3 wt% IL@SiO2 nanocapsules showed the optical tribological propertied. The corresponding friction coefficient of PA6 composites reduced by 38.9%, and the wear rate also showed a 60.7% decrease compared with pure PA6. Unlike most microcapsules, the addition of nanocapsuels did not cause an undesirable and obvious decrease in mechanical properties of PA6. Anti-wear and friction-reduction mechanism were depth analyzed, and results revealed that IL core and SiO2 wall in nanocapsules synergistically contribute to improve self-lubricating performance of PA6 composites.