Kinetics of miniemulsion polymerization of 1,6-hexanediol diacrylate (HDDA) was investigated. The particle size of microgel particles remained relatively constant (ca. 270 nm) during polymerization in the temperature range 65-75 degrees C. The model-fitting method in combination with the model-free method was used to determine the relevant kinetic parameters. The droplet nucleation involved in the miniemulsion polymerization process was satisfactorily predicted by the nucleation Avrami-Erofeyev model {g(alpha)= [-ln(1 - alpha)](1/2)}. The overall activation energy (E = ca. 75 kJ mol(-1)) determined by the model-fitting and model-free methods is quite close to the overall activation energy (ca. 80 kJ mol(-1)) for polymerization initiated by a thermal initiator. By contrast, the conventional model [g(alpha) = -1/2ln(1 - alpha)] was incapable of adequately predicting the polymerization kinetic data. The miniemulsion polymerization was characterized by DSC, DLS and TEM. (C) 2016 Elsevier B.V. All rights reserved.