Binary systems based on aromatic amines with a view of development of novel hardeners for epoxy resins

Three binary systems based on aromatic amines [4,4′-diaminodiphenylmethane (DDM), 4,4′-diaminodiphenyl sulfone (DDS), 4,4′-diaminodiphenyl ether (DDE) and m -phenylenediamine (MPDA)] were investigated by differential scanning calorimetry (DSC). Phase diagrams for different compositions were constructed. The DSC results showed that all binary systems form simple eutectic mixtures. Formation of eutectic physical mixture of MPDA–DDM and MPDA–DDS was confirmed by powder XRD study. In the case of DDE–DDS system, it was found that besides the eutectic mixture a small amount of the charge transfer complex forms with the novel crystal structure.