Primary and secondary amino-functionalized polyethylenes were synthesized from commercially available maleic anhydride-modified polyethylene by reaction with mono-tert-butoxycarbonyl-protected diamines, N-(tert-butoxycarbonyl)-1,6-diaminohexane (tBocHMDA), and N-(tert-butoxycarbonyl)-N-ethyl-1,6-diaminohexane (tBocEtHMDA) followed by deprotection with trifluoroacetic acid. The structures of amino-functionalized polyethylenes were characterized by NMR and IR spectroscopies, and the data compared favorably to that of the corresponding model compounds. The amino-functionalized polymers showed significantly improved adhesive strength toward thermoplastic polyurethanes as compared to the parent maleic anhydride-modified polyethylene.