Organocatalytic Polymerization of Morpholine-2,5-diones toward Methionine-Containing Poly(ester amide)s: Preparation and Facile Functionalization

Methionine-containing poly­(ester amide)­s (PEAs) were potentially attractive biodegradable materials whose postpolymerization modification via “methionine click” enlarges the scope of poly­(ester amide)­s but were surprisingly unexplored. In this manuscript, the controlled organocatalytic ring-opening polymerization (ROP) of methionine-derived morpholine-2,5-diones (MDs) was implemented utilizing 1,8-diazabicyclo[5.4.0]­undec-7-ene/thiourea (DBU/TU) binary organocatalytic system. A range of methionine-containing poly­(ester amide)­s having molecular weights (MWs) between 8.1 and 28.2 kg mol–1 were thus generated with low distributions (Đ = 1.07–1.12). Moreover, the obtained poly­(ester amide)­s could undergo postpolymerization modification by methionine click functionalization to generate poly­(ester amide)­s with a range of functionality in a facile procedure. Finally, the obtained poly­(ester amide)­s exhibited variable glass transition temperatures and could be manufactured into transparent films by hot compression, demonstrating their great potential for applications.