Direct grafting poly(methyl methacrylate) from TiO2 nanoparticles via Cu2+-amine redox-initiated radical polymerization: An advantage of monocenter initiation



Cu2+ can oxidize amines to generate radicals to initiate radical polymerization of electron-deficient monomers under mild conditions. Here, CuSO4-catalyzed redox-initiated radical polymerizations of methyl methacrylate from amino-functionalized TiO2 nanoparticles (TiO2-NH2 nanoparticles) was performed to prepare TiO2 nanoparticles grafted with poly(methyl methacrylate) (TiO2-g-PMMA hybrid nanoparticles) in dimethylsulfoxide or N,N-dimethylformamide at 90°C. Infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy confirmed the presence of the grafted PMMA and the grafting yield was about 50 wt%. Microscopy and particle-size analysis indicated that TiO2-g-PMMA nanoparticles had a good affinity to organic media. Because only aminyl radical ([BOND]NH•) on TiO2 nanoparticles formed in Cu2+-amine redox-initiation step, there was no free PMMA chains formed during polymerization. Thus, our protocol provides a facile strategy to prepare inorganic/organic hybrid nanoparticles via one-pot Cu2+-amine redox-initiated free radical polymerization. POLYM. ENG. SCI., 55:735–744, 2015. © 2014 Society of Plastics Engineers