Kinetics of the reactive blending of epoxy with a four-armed epsilon-caprolactone-based carboxylic acid end-functionalized oligomer was analyzed with a model-free approach. The employment of a dual catalyst system ensured high density of crosslinking in the blends and minimized phase separation even when comparatively high concentration of the oligomer was incorporated. The two reactions were examined separately before analysis of the dual-catalyzed system. The apparent activation energy of the single-catalyzed reactions could be seen to fall into three regimes. It is proposed that regime I is due to reaction control, the middle part (II) to mass transport, and the high conversion tail (III) to structural control. The results of a thermal analysis carried out on the crosslinked samples corresponded well with the findings of the kinetic analysis. The combined kinetic and thermal results can be used in optimization of the crosslinking process. (c) 2006 Wiley Periodicals, Inc.