Epoxy resin coatings modified by ionic liquid. Study of abrasion resistance

In the present study, an epoxy resin coating containing a uniformly dispersed 9 wt% of the ionic liquid 1-octyl-3-methylimidazolium tetrafluoroborate (EP+9%[OMIM]BF4) has been applied by spin coating on a neat epoxy substrate, and its abrasion resistance under multiple scratch has been compared with that of neat epoxy coating. EP+9%[OMIM]BF4 presents the lowest surface damage after 15 successive scratches. The ionic liquid-modified coating reduces instantaneous penetration depth in a 13% and residual depth in a 22% with respect to EP, and increases viscoelastic recovery (after 30 seconds) in a 7.6%. The lubricating effect of the ionic liquid reduces the coefficient of friction up to the tenth scratch number. EP and EP+9%[OMIM]BF4 have also been obtained in the form of spin-coated films with similar visual transparency. Dynamic-mechanical characterization of the films under a tensile configuration confirms that the addition of the ionic liquid increases the ductility and reduces the glass transition temperature of the epoxy resin.