SURFACE MODIFICATION OF NANOSIZED ALUMINA HYDRATE

To enhance the dispersity of nanosized alumina hydrate (Al_2O_3·xH_2O)in organic solvent and polymer matrix,an effective surface modification method was developed by grafting PMMA onto the Al_2O_3·xH_2O nanoparticles. The Al_2O_3·xH_2O and the silane coupling agent KH570 (mass ratio is 1∶1) were firstly violently stirted in ethanol at boiling point for 4 h, then the silane treated nanopowder and the methacrylate (MMA) (mass ratio is 1∶2) copolymerized at 65 ℃ for 6 h in the water/ethanol (volume ratio is 1∶1)system. The product and its dispersion properties were investigated by FT/IR, DTA, SEM and TEM etc. Results show that PMMA is engrafted on the surface of nanosized Al_2O_3·xH_2O and thus greatly change its surface characteristics from hydrophilia to lipophilicity. Great dispersity and stability can be obtained for this product in toluene.