Epoxidized natural rubber–magnetite nanocomposites for oil spill recovery

Abstract

New, eco-friendly nanocomposite materials have been synthesized from natural rubber (NR) and magnetite nanoparticles for the first time. The poor oil resistance of natural rubber is exploited for the removal of oil spills. Towards this purpose, mildly epoxidized natural rubber (ENR)–magnetite nanoparticle (MN) nanocomposites are prepared and the absorption of petrol (gasoline) is studied. The extent of epoxidation is controlled in such a manner that the NR does not lose its elasticity while retaining to a significant degree its oil absorbing property. Epoxidation also serves as a means for binding sufficient quantity of MNs so that the composite can be recovered using a magnetic field. ENR with 5 mol% of epoxidation served as the best absorbent among all the absorbents studied as it was stable in petrol even after many days of immersion. It is observed that the ENR–MN nanocomposite absorbs 7 g of petrol per gram without any mass loss. The material was reused for several cycles without much loss in the capacity. The petrol uptake of ENR–MN is greater than that of butyl rubber which is the most commercially used rubber for oil spill removal. Porous rubber was also synthesized for the first time as oil uptake is facilitated not only by the hydrophobicity but also by the capillary absorption. Porous ENR absorbed a relatively larger amount of oil and exhibited the highest stability in oil. All the sorbents have quite high absorption capacities to be applied practically with a very low water uptake and a few of the absorbents could be satisfactorily reused. The model studies promise their potential use in the environmental field.