Abstract
Summary: Poly(ester amide)s derived from glycolic acid and ω‐amino acid units, such as aminohexanoic or aminoundecanoic acids, are synthesized by a thermal polycondensation reaction that involves the formation of metal halide salts. Polymerization kinetics of different metal salts are studied by isothermal and nonisothermal methods and the corresponding parameters compared. The condensation reaction begins in the solid state for the aminohexanoic derivatives, although a rapid liquefaction is observed. On the other hand, the melting temperatures of the sodium and the potassium chloroacetylaminoundecanoate salts are lower than the reaction temperatures, and consequently polycondensation proceeds fully in the liquefied state. These polymers are characterized by an alternate disposition of ester and amide groups and can be obtained with high molecular weights and short polymerization times. Thermal properties (glass transition and melting temperatures) of the two new polymers are determined and compared. Thermal stability is also investigated; the results indicated that decomposition temperatures were always far from both reaction and polymer fusion temperatures.
DSC heating scans performed at different rates for potassium chloroacetylaminoundecanote.
magnified imageDSC heating scans performed at different rates for potassium chloroacetylaminoundecanote.