Preparation and properties of core-shell nanosilica/poly(methyl methacrylate-butyl acrylate-2,2,2-trifluoroethyl methacrylate) latex

摘要

A core-shell nanosilica (nano-SiO_2)/fluorinated acrylic copolymer latex, where nano-SiO2 served as the core and a copolymer of butyl acrylate, methyl methacrylate, and 2,2,2-trifluoroethyl methacrylate (TFEMA) served as the shell, was synthesized in this study by seed emulsion polymerization. The compatibility between the core and shell was enhanced by the introduction of vinyl trimethoxysilane on the surface of nano-SiO_2. The morphology and particle size of the nano-SiO_2/poly(methyl methacrylate-butyl acrylate-2,2,2-trifluoroethyl methacrylate) [P(MMA-BA-TFEMA)] core-shell latex were characterized by transmission electron microscopy. The properties and surface energy of films formed by the nano-SiO _2/P(MMA-BA-TFEMA) latex were analyzed by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and static contact angle measurement. The analyzed results indicate that the nano-SiO _2/P(MMA-BA-TFEMA) latex presented uniform spherical core-shell particles about 45 nm in diameter. Favorable characteristics in the latex film and the lowest surface energy were obtained with 30 wt % TFEMA; this was due to the optimal migration of fluorine to the surface during film formation. The mechanical properties of the films were significantly improved by 1.0-1.5 wt % modified nano-SiO_2.