Comparative degradation data of polyesters and related poly(ester amide)s derived from 1,4‐butanediol, sebacic acid, and α‐amino acids

Abstract

ABSTRACT:Two new sequential poly(ester amide)s (PEAs) derived from 1,4-butanediol, sebacic acid, and L-alanine (PABA8) or glycine (PGBG8) are prepared and characterized. For comparative purposes the related polyesters (PEs) 4,10 and 6,10 are also studied. The calorimetric analysis shows that the inclusion of amino acids improves the thermal properties such as the melting temperature without a significant reduction in their thermal stability. All polymers show hydrolytic and enzymatic degradability. The degradation rates of the PEAs are higher for the alanine derivative (PABA8) because of its low crystallinity and the higher specificity of the essayed proteolytic enzymes. The PEs are only degraded faster when enzymes with esterase activity are employed.

Degradable Poly(ester amide)s for Biomedical Applications

“…This procedure has been successfully applied to prepare poly(ester amide)s containing -amino acid units by reaction of a diol with a diamide-diester previously obtained by condensation of a diacid chloride with an -amino acid methyl ester [23,24] (Figure 3). Secondary reactions derived from the required high temperatures constitute the main disadvantage of this method that may limit the final molecular weight and cause problems when monomers have functional side groups highly susceptible to undertake these undesirable reactions.…”

Concept and Synthesis of Poly(ester amide)s with One Isolated, Two or Three Consecutive Amide Bonds Randomly Distributed Along the Polyester Backbone

“…Other types of preformed monomers were condensed with activated esters in solution [37,[42][43][44][45][46][47][48] or with dicarboxylic acid dichlorides or activated esters by interfacial polymerisation [49][50][51][52][53][54][55][56][57]. Polymerization of diamide-diesters with diols yields alternating PEAs which have a higher degree of crystallinity than the corresponding random PEAs [58][59][60].…”

“…The incorporation of amino acids makes the polymer biocompatible. Preformed monomers can be synthesized by condensing amino acids such as alanine or glycine with diols to form diester-diamine salts which are then reacted with dicarboxylic acids or their dichlorides to form alternating PEAs [41,43,47,48,[51][52][53][54][55][61][62][63]. α,ω-Amino-alcohols-based alternating PEAs can also be obtained by condensing dicarboxylic acids with linear aliphatic amino alcohols with varying numbers of methylene groups [41,64].…”

Poly(ester-amide)s Derived From Adipic Acid, 1,4-Butanediol and β-Alanine: Synthesis and Characterization

“…Alternating PEAs are synthesized by reacting diol or diacid derivatives with intermediate compounds, such as diamine-terminated diesters or diester-terminated diamides (20)(21)(22)(23)(24)(25)(26)(27) or by ring-opening polymerization of a cyclic morpholine-2,5-dione derived from natural a-amino acids and a-hydroxy acids (28)(29)(30)(31)(32). On the other hand, block PEAs can be carried out by ringopening polymerization of e-caprolactone initiated by amine-terminated peptides or by ring-opening polymerization of a-amino acid N-carboxyanhydrides (NCAs) initiated by amine-terminated polylactide or poly(e-caprolactone) (33)(34)(35)(36).…”