Self-Healing of Abrasion Damage in Epoxy Resin–Ionic Liquid Nanocomposites

Abstract

The present work describes the self-healing, under ambient conditions, of abrasion surface damage in epoxy resin (ER) modified by a dispersed ionic liquid (IL) phase. The abrasion resistance of ER containing a 9 wt.% of the IL 1-octyl, 3-methylimidazolium tetrafluoroborate (ER + 9IL) was determined by multiple scratching under constant load and by single scratching under progressively increasing load, and compared with that of neat ER. ER + 9IL shows higher instantaneous penetration depth and residual depth values than neat ER. In the case of ER, the viscoelastic recovery process ends after 30 min. For ER + 9IL, the recovery process continues with time to reach a total healing of multiple scratch abrasion grooves after 22–25 h at room temperature. For single scratches under the maximum load of 20 N, ER + 9IL shows an 88 % reduction in surface damage with respect to ER, after 24 h at room temperature. The addition of IL reduces hardness and tensile strength, while increases elongation at break by a 42 %. Hardness test scars on ER + 9IL show an area reduction of approximately 55 % after 5 h. Results are discussed upon the basis of optical and electron (SEM) microscopy and 3D profilometry.