New poly(ester amide ether amide)s from a novel flexible diamine and different diacid chlorides using TMSCl for in situ silylation

A novel flexible diamine with built-in ester, amide and ether groups named terephthalic acid bis(4-{2-[2-(2-amino ethoxy)ethoxy]ethyl carbamoyl}phenyl) ester (TABE), was synthesized via two steps. Nucleophilic reaction of 4-hydroxybenzoic acid with terephthaloyl chloride in the presence of NaOH yielded terephthaloyl bis (4-oxybenzoic) acid (TOBA). The diamine (TABE) was prepared via two direct and indirect methods. In the indirect method TOBA was converted to related diacid chloride and reacted with 1,8-diamino-3,6-dioxaoctane (DADO). Direct method was achieved through the reaction of TOBA with DADO via Yamazaki method. TOBA and TABE were fully characterized and TABE was used to prepare new poly(ester amide ether amide)s through polycondensation with different diacid chlorides in the presence of trimethylchlorosilane (TMSCl). The polymers were characterized using conventional methods and their physical properties including inherent viscosity, thermal behavior, thermal stability, crystallinity, and solubility were studied. The polymers showed good thermal stability and improved solubility.