The efficient formation of cyclic polyesters from the ring-opening polymerization of lactide, ϵ-caprolactone, and β-butyrolactone catalyzed by a 1,4-dithiabutanedyl-2,2′-bis(4,6-dicumylphenol) [OSSO]-FeCl complex activated with cyclohexene oxide was achieved. The catalyst was very active (initial turnover frequency up to 2718 h−1), robust, and worked with a monomer/Fe ratio up to 10 000. The formation of cyclic polymers was supported by using high-resolution matrix-assisted laser desorption ionization (MALDI) MS, and the average ring size (≈5 kDa for cyclic polylactide) independent of the reaction conditions. A monometallic ring-opening polymerization/cyclization mechanism was proposed from the results of a kinetic investigation.
Cyclic Polyester Formation with an [OSSO]-Type Iron(III) Catalyst
Impemba S.;Della Monica F.;Grassi A.;Capacchione C.
;Milione S.
2020-01-01
Abstract
The efficient formation of cyclic polyesters from the ring-opening polymerization of lactide, ϵ-caprolactone, and β-butyrolactone catalyzed by a 1,4-dithiabutanedyl-2,2′-bis(4,6-dicumylphenol) [OSSO]-FeCl complex activated with cyclohexene oxide was achieved. The catalyst was very active (initial turnover frequency up to 2718 h−1), robust, and worked with a monomer/Fe ratio up to 10 000. The formation of cyclic polymers was supported by using high-resolution matrix-assisted laser desorption ionization (MALDI) MS, and the average ring size (≈5 kDa for cyclic polylactide) independent of the reaction conditions. A monometallic ring-opening polymerization/cyclization mechanism was proposed from the results of a kinetic investigation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
