This paper reports a novel nonlinear optical polymer BP-AVT-TCV functionalized with a thiophene- and tricyanovinyl-substituted chromophore. BP-AVT-TCV was synthesized by the post-tricyanovinylation of an epoxy-based precursor polymer BP-AVT, and had a high molar functionalization degree of chromophore (70 mol.%,). It had an enhanced glass transition temperature (T-g= 164 degrees C) compared with BP-AVT (T-g = 114 degrees C), and a high decomposition temperature (T-d.5% = 295 degrees C). BP-AVT-TCV was further cross-linked to achieve the three-dimensional (313) network of thermosetting polyurethane (PU). The poled PU films revealed an electro-optic (EO) coefficient (gamma(33) ) value of'21 pm/V at a wavelength of 1315 nm. The structures of the polymers were confirmed by FT-IR, UV-Vis, and H-1 NMR spectra. (c) 2007 Elsevier Ltd. All rights reserved.