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 (D = 1.07-1.12). Moreover, the obtained poly(ester amide)s could undergo postpolymerization modification by methionine click functionalization to generate poly(ester amides 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.