Study on the degradability of poly(ester amide)s derived from the alpha-amino acids glycine, and L-alanine containing a variable amide/ester ratio

Two series of poly(ester amide)s prepared from sebacic acid and different r atios of 1,12-dodecanediamine and a diamine that contains both alpha -amino acid residues and ester groups have been synthesized and characterized. In order to maintain hydrogen bonding interactions, two diamines with the sam e number of main chain atoms were selected. The series differ on the nature of the alpha -amino acid residue: glycine or L-alanine. The calorimetric a nalysis shows that melting temperatures increase as the amide/ester ratio d oes. Polymers derived from L-alanine show lower crystallinities and melting temperatures than those constituted by glycine units. Hydrolytic and enzym atic degradabilities of both series of poly(ester amide)s have also been st udied. The ratio and nature of alpha -amino acid residues in the chemical r epeat unit greatly affect the degradation rate. (C) 2001 Elsevier Science L td. All rights reserved.