An α-iminocarboxamide nickel complex was activated by trimethylaluminum (TMA) and used in the polymerization of ethylene and its copolymerization with 10-undecen-1-ol. The best activity was observed upon activation with 9 equiv of TMA at a temperature of 26 °C. NMR spectroscopic studies did not show 10-undecen-1-ol incorporation. However, FTIR analyses suggest the incorporation of a very small amount of comonomer, which affects the glass transition temperature, the degree of branching, and the mechanical properties of the materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 54–59, 2008