Preparation of styrene‐acrylic emulsion by using nano‐SiO 2 as seeds

A styrene‐acrylic/SiO 2 nanoparticle composite emulsion was prepared by using SiO 2 nanoparticles as seeds. The effect of factors such as the level of nano‐SiO 2 , reaction temperature and ultrasound treatment of nano‐SiO 2 on the stability of the polymerization reaction was investigated. Water‐resistance of the emulsion was measured. The level of nano‐SiO 2 in the emulsion was determined by inductively coupled plasma (ICP) spectrometry. The particle morphology of the emulsion with nano‐SiO 2 was observed with transmission electron microscopy (TEM). The kinetics of the polymerization was also studied at various temperatures and various levels of nano‐SiO 2 . They showed that the level of nano‐SiO 2 and reaction temperature had a great influence on the monomer conversion, particle size, coagulum content and viscosity of the emulsion. Nano‐SiO 2 treated by ultrasonics can increase the coagulum content greatly, but it does not improve the water resistance of the emulsion. The level of nano‐SiO 2 in the emulsion was lower than the theoretical value. The reaction kinetics indicated that the level of nano‐SiO 2 had less influence on the reaction rate than the reaction temperature. Even a small amount of nano‐SiO 2 can decrease the reaction rate. Copyright © 2004 Society of Chemical Industry