Novel Polyesteramide‐Based Diblock Copolymers: Synthesis by Ring‐Opening Copolymerization and Characterization

Abstract

Block copolymers based on a polyesteramide sequence and a polyether block were synthesized in bulk at 250 °C by ring‐opening copolymerization (ROP) of ε‐caprolactone (CLo) and ε‐caprolactam (CLa) as initiated by Jeffamine® M1000, i.e., ω‐NH2 copoly[(ethylene oxide)‐co‐(propylene oxide)] copolymer [P(EO‐co‐PO)‐NH2]. For an initial molar ratio of [CLa]0/[CLo]0 = 1, the copolymerization allowed for the formation of a diblock copolymer with a statistical polyesteramide sequence, as evidenced by 13C NMR. Investigation of the ROP mechanism highlighted that CLo was first polymerized, leading to the formation of a diblock copolymer P(EO‐co‐PO)‐b‐PCLo‐OH, followed by CLa hydrolysis to aminocaproic acid that inserted into the ester bonds of PCLo via aminolysis and subsequent condensation reactions. The outcome is the selective formation of P(EO‐co‐PO)‐b‐P(CLa‐co‐CLo)‐OH diblock copolymers where the composition and length of the polyesteramide sequence can be fine‐tuned by the [CLa]0/[CLo]0 and ([CLa]0 + [CLo]0)/[P(EO‐co‐PO)‐NH2]0 initial molar ratios.

Amide-containing segmented copolymers

“…PEAs also demonstrate favorable properties of both polyesters and PA including degradability, excellent toughness, and good processing properties. The biodegradation of PEA segmented copolymers serves as a driving force for the development and understanding of more environmentally friendly plastics as a result of the growing issue of plastic waste in the environment [91]. Besides PEA TPE applications, copolymers also showed promise for biomedical applications because of biocompatiblility, and tunable biodegradation rates.…”

Synthesis of polylactide/poly(ethylene glycol) diblock copolymers with functional endgroups

“…The repeat unit number of PPO segments is equal to 2, as determined from the integrations of the peaks belonging to the methine group of PO units and to that adjacent to the amine end, while that of the PEG block is found to be 31. Since the length of PPO segments is much shorter than that of PEG, the structure of Jeffamine can be simplified as H 2 N‐PEG‐NH 2 …”

Quasi‐alternating polyesteramides from ε‐caprolactone and α‐amino acids

“…Various approaches have been employed to synthesize amino acid‐based polyesteramides exhibiting block, random, or alternating structures. Block amino acid‐based polyesteramides are prepared by the ring‐opening polymerization of ɛ‐caprolactone initiated by amine‐terminated peptides or by the ring opening polymerization of α‐amino acid N‐carboxyanhydrides (NCAs) initiated by amine‐terminated polylactide or poly(ɛ‐caprolactone) .…”