Synthesis, characterization and hydrolytic degradation of novel biodegradable poly(ester amide)s derived from Isosorbide and α-amino acids

Abstract

A series of poly(ester amide)s (PEAs) derived from the nontoxic building blocks, isosorbide, α-amino acids (L-phenylalanine, L-alanine, L-valine and glycine) and dicarboxylic acids was synthesized by interfiactial polymerization using a two-step method. The majority of PEAs were amorphous except for some glycine containing polymers. The PEAs showed good thermal stabilities and had Tg temperatures from 115.9 to 182.6 °C. The hydrolytic degradation behavior of the PEAs was followed by weight loss in both alkaline solution (pH 9) and under stimulated physiological conditions (pH 7.4) in phosphate buffer saline solution at 37 °C. The polymers with hydrophobic pendent or rigid dicarboxylic acid groups prevent degrading media from penetration into the polymer bulk leading to slow degradation rate. The monomers synthesized were characterized by FTIR, 1H and 13C NMR spectroscopy, the PEAs structures were confirmed by FTIR, 1H and 13C NMR spectroscopy and their thermal properties were studied by TGA and DSC.