Poly(ester amide)s derived from L‐tartaric acid and amino alcohols. II. Aregic polymers

A series of aregic poly(ester amide)s (a‐PEAT6) with ester/amide ratios (a : b) varying from 1 : 19 to 1 : 2 were prepared with L ‐tartaric acid, 6‐aminohexanol, and 1,6 hexanediamine as the starting materials. Polycondensation in a solution of the diamine with mixtures of pentachlorophenyl‐activated di‐O‐methyl‐L ‐tartaric and 6‐aminohexyl‐di‐O‐methyl‐L ‐tartaric acids led to a‐PEAT6(a : b), with the a : b ratio determined by the composition of the feed. The newly synthesized poly(ester amide)s were characterized by elemental analysis, size exclusion chromatography, and IR and NMR spectroscopy. They had number‐average molecular weights between 25,000 and 45,000 and were highly crystalline, showing melting temperatures ranging from 100 to 230 °C and glass‐transition temperatures oscillating between 50 and 100 °C. The thermal degradation of a‐PEAT6(a : b) began above 200 °C and concluded with a final weight loss between 60 and 90% of the initial mass. The process evolved with the formation of cyclic tartarimide units and extensive main‐chain scissions. The degradation mechanism is discussed in relation to the chemical composition and microstructure of the polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2687–2696, 2000