A kinetic analysis of the cyclotrimerisation reaction of a dicyanate ester monomer catalysed by cobalt(II) acetylacetonate and nonylphenol in air and argon atmospheres has been carried out by differential scanning calorimetry (DSC). Dynamic and isothermal DSC scans as well as the glass transition temperature are the experimental data obtained. From isothermal scans a higher cyanate conversion in air than in argon was obtained. The cyanate conversions are satisfactorily described with a second-order kinetic equation in the kinetically controlled region, and by in-order (m < 1) equation after vitrification is reached. Activation energies determined by different procedures agree among them, showing slightly higher values in argon than in air. (C) 2004 Elsevier B.V. All rights reserved.