Synthesis, characterization and degradation studies on the series of sequential poly(ester amide)s derived from glycolic acid, 1,6-hexanediamine and aliphatic dicarboxylic acids

Sequential poly(ester amide)s derived from glycolic acid, 1,6-hexanediamine and dicarboxylic acids with an even number of methylene groups have been synthesized by two different methods. Molecular weights are higher when a new thermal polycondensation reaction based on the formation of metal halide salts is employed. The thermal properties of the series of new polymers have been studied by differential scanning calorimetry. In all cases, a melting point in the 115-150 degrees C range has been measured, which tends to the melting point of polyethylene as the methylene content increases. Thermogravimetric analysis indicates that this series of polymers is stable through fusion, and consequently these new poly(ester amide)s can be easily processed from the melt. Hydrolytic and enzymatic degradation studies, where weight losses, intrinsic viscosity changes, NMR spectra and calorimetric data of degraded samples were evaluated, have also been undertaken. The polymers seem interesting because of their application as new biodegradable materials. (c) 2005 Elsevier Ltd. All rights reserved.