The synthesis and the study of DC electrical transport properties (electrical conductivity, sigma, and Seebeck coefficient, S) as a function of temperature of some recently synthesized nylon 6/12 copolymers with 0, 5, 10, 20, 30, and 50 wt % lauro-lactam (LL), respectively, are reported. Nylons were obtained by rotational molding via the anionic activated copolymerization of e-caprolactam and LL. As evidenced by XRD analyses, they are semicrystalline. The temperature dependences of U and S are typical for polycrystalline semiconducting (p-type) materials. The activation energy of electrical conduction lay in the range 0.79-1.22 eV, while the ratio of charge carrier mobilities ranged between 0.53 and 0.77. (c) 2007 Wiley Periodicals, Inc.