A new family of liquid crystalline columnar polyethers was obtained by modification of Poly(epichlorohydrin-co-ethylene oxide) (P(ECH-co-EO)) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy]benzoate, under different conditions. The highest modification degree that we could achieve was 69%. The copolymers were fully characterized by 1H and 13C nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction (XRD). All copolymers exhibited liquid-crystalline columnar behavior whose range of stability depended on the modification degree. X-ray diffraction experiments on oriented samples showed that the dendrons are approximately perpendicular to the column axis and that their average number per unit cell ranged from 5 to 6. The formation of a stable columnar mesophase in the polyether should determine the presence of a continuous ion channel along the column axis. Therefore, these copolymers are suitable candidates for the preparation of membranes for small cation transport, in agreement with the results that we obtained by using poly(oxy-1-chloro methylethylene) (PECH) modified with the same dendron. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers