Published : 2022-09-01

Amines as (co)initiators of cyclic esters' polymerization


A review reports on application of amines as (co)initiators in the ring-opening polymerization of aliphatic cyclic esters. First, the use of tertiary amines (R3N) as initiators of the controlled polymerization of highly strained, four-membered b-lactone (b-propiolactone, PL) is described [equation (1)]. Then attempts at the high temperature polymerizations of the medium strained, six- and seven-membered d- and e-lactones initiated with primary amines (RNH2) or a-amino acids are briefly discussed. Finally, it is shown in more detail that the best results have been obtained recently in the processes catalyzed additionally with tin(II) octoate [Sn(Oct)2]. Mechanisms of these polymerizations are also discussed. Results of the kinetic studies [equation (9) and (10)] as well as 1H NMR, MALDI TOF mass spectrometry, and size exclusion chromatography (SEC) measurements, carried out in the authors' laboratory, indicate that polymerizations of e-caprolactone (CL) or L,L-lactide (LA) initiated with RNH2/Sn(Oct)2 fulfill living process criteria and therefore allow to fully control the syntheses of the corresponding polymers. The selected syntheses applications, such as preparation of the copolymers N-carboxyanhydrides of a-aminoacids and LA [equation (7)] or star-shaped polymers based on polyamino dendrimers [formula (I) and (II)] are also described.





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Duda, A., Biela, T., Kowalski, A., & Libiszowski, J. (2022). Amines as (co)initiators of cyclic esters’ polymerization. Polimery, 50(7-8), 501-508. Retrieved from