Studies on Acrylic Emulsion Polymerization Containing Hydrophilic Hydroxyl Monomer in the Presence of Nano‐SiO2Particles

Emulsion polymerization with nano‐scale SiO2 particles as seeds composed of methyl methacrylate (MMA), butyl acrylate (BA), hydroxyethyl methacrylate (HEMA), and acrylic acid (AA) was studied from varying reaction temperatures, level of SiO2 particle, HEMA, and emulsifier. The morphology of the emulsion particle was examined with a transmission electron microscope (TEM). The results showed that the addition of nano‐SiO2 particles decreased the coagulum greatly when its level was lower than 7%. The coagulum also decreased with the increasing of temperature from 65°C to 75°C. The level of HEMA and emulsifier had little influence on the coagulum in the presence of nano‐SiO2. The particle size of the emulsion increased with the increase of level of nano‐SiO2 and HEMA. Part of the emulsion particles connected together due to the existence of HEMA, and yet some of the nano‐SiO2 particles were not covered with polymer.