Systems from polyamide-6 (PA-6) and partly crosslinked polyethyl acrylate (PEA), containing residual crosslinking agent (diglycidyl ether), were studied using differential calorimetric methods. It is shown that the dramatic changes in the morphology of the blends can be detected and interpreted using Delta C-p-values of the components as well as their glass transition temperatures. An increase in the Delta C-p-values is observed with increasing PEA content because the degree of crosslinking is reduced by simultaneous increase in the amount of crosslinking agent in the mixture. Remarkably the values are always lower than those of pure PA-6 with similar degrees of crystallinity. The crosslinking agent reacts with both components. In the interface regions copolymers are formed.