Novel Poly(ether-amide)s Derived from 1,4-(4-Carboxy phenoxy)butane and Ethereal Diamines: Synthesis and Properties

A new series of poly(ether-amide)s (PEAs) containing flexible methylene segments in the main chain were synthesized through a direct polycondensation reaction of 1,4-(4-carboxy phenoxy)butane with five ethereal diamine derivatives in a medium containing N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride, and pyridine. The resulting polymers were fully characterized by proton nuclear magnetic resonance spectroscopy (H-1 NMR), Fourier transform infrared (FTIR) spectroscopy, elemental analyses, inherent viscosity, and solubility tests. The thermal properties of the polymers were examined by thermal gravimetric analysis (TGA) and differential thermal gravimetric (DTG). The glass-transition temperatures of the PEAs were determined by differential scanning calorimetry (DSC). The diacid was prepared from a reaction of 4-hydroxy benzoic acid with 1,4-dibromo butane in the presence of NaOH. New ethereal diamines were synthesized by a two-step reaction. In the first step, dinitro compounds were prepared from a reaction of two equimolars 4-nitrophenol and one equimolar of dibromo compounds. The resulting dinitro compounds were then reduced using 10% Pd-C, ethanol and hydrazine monohydrate.