The synthesis of amino-terminated telechelic poly(propylene glycol) and polyisobutylene from their corresponding dihydroxy-terminated derivatives was studied. The synthesis of these aminotelechelics was achieved by the coupling of imidazolyl-formates with ethylenediamine. The structure of the resulting amino-functionalized polymers was determined by H-1 NMR, C-13 NMR, and matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry. On the basis of the spectroscopic and spectrometric results, a complete conversion of dihydroxy termini into diamino end groups was observed; that is, the number-average functionality was found to be 2. (C) 2003 Wiley Periodicals, Inc.