H-1 T-1 and T-1p measurements together with FID function fitting were used to investigate the effect of electron beam irradiation on the dynamics of a poly(ether-block-amide). Rigid polyamide and mobile polyether phases art: seen in the FID of the control polymer. Irradiation causes a decrease in mobility of the mobile phase. Spin diffusion evident in the T-1 and T-1p shows qualitatively a phase separated morphology on the 2 nm scale and prevents a clear interpretation of the changes caused by irradiation. Only minor differences were seen in the C-13 CPMAS NMR spectra of the control and irradiated polymers. (C) 2001 Elsevier Science Ltd. All rights reserved.