Diamines represent, besides many technically important classes of substance, a particularly interesting family of molecules for the purpose of testing group-contribution models. A differential scanning calorimetry (DSC) was used to determine binary (solid + liquid) phase equilibria for {diamines NH2-(CH2)(n)-NH2 (n = 6,8,9, and 12) + biphenyl} mixtures. Results obtained with this technique are compared with those predicted by modified UNIFAC (Larsen and Gmehling) and DISQUAC models. It was found out that all the systems are eutectic and deviations were observed between experimental and predicted SLE. (c) 2005 Elsevier Ltd. All rights reserved.