A kinetic study of the trimerization reaction of bisphenol A dicyanate ester with an aromatic imidazolium-based ionic liquid (IL) as additive is performed using dynamic and isothermal differential scanning calorimetry. The reaction follows second-order autocatalytic kinetics, and a slight acceleration effect is observed in the presence of the aromatic IL relative to the neat resin. The activation energy also increases with the IL additive, whereas the glass transition temperature (T-g) is depressed, consistent with the Fox equation and a homogeneous one-phase material. A model incorporating diffusion effects is able to describe the dynamic and isothermal curing data for both the neat resin system and that containing aromatic IL. A comparison with aliphatic-based IL additive indicates that the reaction is more accelerated with aliphatic IL than with the aromatic IL in spite of the fact that the aliphatic additive phase separates during cure. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019