Structure and swelling behaviour of hydrophilic epoxy networks prepared from alpha,omega-diamino terminated poly (oxypropylene)-block-poly(oxyethylene)-block-poly(oxypropylene) and diglycidyl ether of brominated Bisphenol A in dependence on the initial molar ratio of reactive amino and epoxy groups has been investigated by small- and wide-angle X-ray scattering (SAXS and WAXS), differential scanning calorimetry (DSC) and dynamic mechanic analysis (DMA). Anomalous swelling behaviour of the networks in water has been found. The anomaly is attributed to the changing microphase separation in the networks controlled by their composition and crosslinking density, and inhomogeneous swelling on nanometer space scale. (C) 2004 Elsevier Ltd. All rights reserved.