Immobilization of vinyl polymer chains on macroporous silica gel by atom transfer radical polymerization and surface structure control

Abstract

The commercially available macroporous silica gels (Daisogel SP-1000, particle diameter 7 μm, pore size 1000 Å) were utilized as a starting material for the atom transfer radical polymerization, and the silica gels grafted by polystyrene, poly(methyl methacrylate), and poly(2-hydroxyethyl methacrylate) were effectively synthesized using copper chloride/N,N,N′,N′,N′-pentamethyldiethylenetriamine or N-(n-propyl)-2-pyridylmethanimine complex. The amount of the immobilized polymers and the surface area of the obtained gels were facilely controllable by changing the polymerization time. These results were confirmed by BET experiments, SEM, and TG measurements. Various gels bearing the surface areas from 25.0 to 0.99 m2/g were synthesized by immobilization of 1.3∼2.5 g of polymers to one g of silica gel.