Polydepsipeptides: Ring‐opening polymerization of 3‐Methyl‐2, 5‐Morpholinedione, 3,6‐Dimethyl‐2,5‐morpholinedione and copolymerization thereof with D, L‐Lactide

Poly (ester‐amide)s were synthesized by ring‐opening polymerization of 2,5‐morpholinedione derivatives. The monomers: 3‐methyl‐ and 3,6‐dimethyl‐2,5‐morpholinedione were prepared first, and subsequently polymerized with tin(II) bis(2‐ethylhexanoate) as an initiator at 145°C in bulk. Copolymerizations with D, L‐lactide were also investigated; in this way copolymers with higher molecular weight were obtained, which provide materials with a wider range of properties.