Kinetics of acrylate emulsion polymerization containing hydrophilic hydroxyl monomer in the presence of nano-SiO2 particles

Kinetics of acrylate emulsion polymerization containing hydrophilic hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) in the presence of nano‐SiO2 were investigated. The influence of temperature, emulsifier level, hydroxyl monomer content and the level of nano‐SiO2 on monomer conversion, polymerization rate (Rp), and the particle size was studied. The results showed that the presence of nano‐SiO2 increased the Rp when the level was below 5% but decreased when the level was above 7.5%, the more levels, the more seriously. As the temperature and emulsifier levels increased, and the presence of hydroxyl monomer, the Rp increased. The active energy of the system was 142.01 kJ/mol and the relationship of Rp and the concentration of emulsifier (E) was Rp ∞ [E]0.38. The mean particle size increased, particle size distribution became broader as the nano‐SiO2 levels increased. Copyright © 2008 John Wiley & Sons, Ltd.