Synthesis, characterization and degradability of polyamides derived from tartaric acid and diaminoethers

A series of novel polyamides derived from l or d-tartaric acid and α,ω-diaminoethers containing 1, 2, 3 or approximately 70 oxyethylene units in the main chain were synthesized and characterized. Polycondensation in solution of the diaminoethers with di-O-methyl tartaric acid activated as pentachlorophenyl ester was used for the synthesis of these poly(ether tartaramide)s. Polymerization degrees oscillated between 10 and 140 depending on the length of the oxyethylene segment. These polyamides are highly hygroscopic and soluble in water. They are semicrystalline with melting temperatures ranging from 50 to 190 °C, and thermally stable up to 250 °C. Chiro-optical properties were found to depend on the configuration of tartaric acid showing both high specific rotations and characteristic circular dichroism ellipticities. Definite X-ray diffraction patterns consistent with the crystalline nature of these polyamides were recorded. Racemates made of enantiomeric pairs were also examined and some evidence indicative of the existence of a crystalline structure different from that present in the optically pure components was found.