Dimethyladipate or diniethylsebacate were polycondensed with all excess of 1,2-ethane diet ill bulk using two different temperature/time Programs. Bismuth(III)n-hcxanoate (BiHex(3)), tin(II)2-ethylhcxanoate (SnOct(2)) and titanium tetrabutoxide were used as catalysts. Only the bismuth catalyst yielded clean telechelic Polyesters having two ethylene glycol endgroups. With SnOct(2) cyclic oligoesters were obtained as byproducts. Ti(OBu)(4) yielded OH-terminated linear chains containing large amounts of diethylene glycol units (detectable LIP to three ether groups Per chain). Furthermore, small amounts of cycles were also formed. Acid-catalyzed polycondensations of ethylene glycol with sebacic acid gave low yields of low oligomers, part of: which contained diethylene glycol units. (c) 2005 Elsevier Ltd. All rights reserved.