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

Abstract

Glycine‐ɛ‐caprolactone‐based and α‐alanine‐ɛ‐caprolactone‐based polyesteramides with a strong tendency to form alternating sequences (degree of randomness = 1.64 and 1.31) were synthesized by melt polycondensation of intermediate hydroxy‐ and ethyl ester‐terminated amides. These intermediates were synthesized by the reaction of equimolar amounts of ɛ‐caprolactone and glycine or L‐α‐alanine ethyl esters in mild conditions. The structure and microstructure of these polyesteramides are discussed on the basis of an in‐depth nuclear magnetic resonance study. Both polyesteramides are semi‐crystalline, but the glycine‐based one presents the highest melting enthalpy. This polyesteramide also exhibits higher Young's modulus and stress at break than its α‐ and β‐alanine counterparts. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44220.

Recent Advances of Poly(ester amide)s-Based Biomaterials

“…have prepared high molecular weight PEAs from dimethyl adipate, 1,4-butanediol, and the bisamide-diol based on CLO and 1,2-diaminoethane or 1,4-diaminobutane that can be easily incorporated in the chain of polymer without any ester amide interchange taking place. , The thermal and mechanical properties of PEAs are only influenced by the amount of crystallizable hard segments in the polymer chains. The associations of CLO with amino acids and CLA with hydroxyl acids were further studied in which the CLO/hydroxyl acids were the sources of ester bond formation and CLA/amino acids were the precursors for amide bonds. , More notably, dual ring opening of both CLO and CLA could also be easily polymerized into PEAs . In spite of the feasibility of CLO and CLA for PEA synthesis, morpholine-2,5-dione and the derivates are more advantageous for preparing oligodepsipeptide PEAs because ester and amide linkages concurrently exist in the alicyclic (Figure ).…”

“…The associations of CLO with amino acids and CLA with hydroxyl acids were further studied in which the CLO/hydroxyl acids were the sources of ester bond formation and CLA/amino acids were the precursors for amide bonds. 38,39 More notably, dual ring opening of both CLO and CLA could also be easily polymerized into PEAs. 40 In spite of the feasibility of CLO and CLA for PEA synthesis, morpholine-2,5-dione and the derivates are more advantageous for preparing oligodepsipeptide PEAs because ester and amide linkages concurrently exist in the alicyclic (Figure 4).…”