The present project is based on the synthesis of new essentially amino-ended copoly(ether sulphone)s which are characterized by the presence of rigid biphenyl units in the main chain. All the compounds have been fully characterized by (H-1 and C-13) NMR, FTIR, and MALDI-TOF MS techniques. Complete assignments of the H-1 and C-13 NMR spectra have been accomplished by comparison with model compounds and literature data. The thermal properties of the copolymers were studied by differential scanning calorimetry (DSC). The glass transition temperature of the copolymers increases as increasing the molar composition of ethere sulphone units containing biphenyl moiety. The copolymers synthesized might find application as reactive toughening agents for multifunctional epoxy resins when high thermal properties are a requirement. (C) 2010 Elsevier Ltd. All rights reserved.