Polyester Obtained by Anionic Polymerization of Ethylketene

Aldoketenes are well known to undergo fast dimerization and trimerization even at low temperatures but have never been polymerized so far. For the first time, ethylketene, synthesized following the Staudinger procedure modified by McCarney, was polymerized anionically in THF with various initiators, at different temperatures (–40 and –78 °C), and with several monomer/initiator ratios. The resulting polymer was composed exclusively of polyester units, and the initiator did not affect the stereoregularity. Molecular weights up to 24 000 g · mol −1 were obtained with lithium‐based initiators. Transfer reactions and the failure to make block copolymers highlighted a non‐living polymerization. T g values around –18 °C and thermal stability up to 160 °C were measured. magnified image