Modified SiO2 microspheres/polyacrylate resin composites for the enhancement of oil-absorbing performance

Inserting inorganic materials into the skeleton of oil-absorbing resin (OAR) would weaken the interchain winding of polymer, regulate the pore channel structure, and thus enhance the oil-absorbing performance. However, the effects of surface modifiers on the oil-absorbing ability have been rarely explored. Herein, SiO2 microspheres coated with three kinds of silane coupling agents (3-aminopropyltriethoxysilane (APTES), γ-(methacryloxypropyl) trimethoxy silane (MEMO) and chlorotrimethylsilane (TMCS)) were composited with P(SMA-co-BA-co-ST) (octadecyl methacrylate (SMA), butyl acrylate (BA) and styrene (ST)). The as-prepared composite resin microspheres (OAR-APTES-SiO2, OAR-MEMO-SiO2 and OAR-TMCS-SiO2) were fully characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), optical microscopy (OM) and thermal gravimetric analysis (TGA). The results showed that the average particle sizes of the as-prepared SiO2 microspheres were nearly 300 nm and the silane coupling agent of APTES exhibited the best surface modification for SiO2 microspheres (grafting rate reached 16.78%). While, the average particle sizes of composite resins (OAR-APTES-SiO2, OAR-MEMO-SiO2 and OAR-TMCS-SiO2) were nearly 1.5 mm, 2 mm and 2.5 mm, respectively. Meanwhile, composite resin OAR-APTES-SiO2 showed the highest saturated oil-absorbing capacities, which were calculated to be 44.97, 38.12, 27.29 and 22.86 g/g for CCl4, CHCl3, CH2Cl2 and gasoline, respectively, under the optimal adding amount of SiO2 (ω(SiO2) = 0.8%), reaching more than 90% of the saturated oil-absorbing capacity in 30 min. Meanwhile, the oil-absorbing capacity of composite resin is 1.34 times higher than that of bare acrylic resin. It can be recycled 7 times without the obvious decrease in oil absorption ability. This study provides a novel method for the preparation of composite materials with high stability, high oil-absorbing capacity and low-saturation oil-absorbing time by regulating the resin pore structure.