Structural, Optical and Thermal Characterization of Wholly Aromatic Poly(ether amide)s Synthesized by Phosphorylation‐Based Condensation Polymerization

Abstract

Abstract[1]To attain high performance polyamides with good thermal properties and enhanced processability, in this study, a series of wholly aromatic poly(ether amides) (PEAs) with different meta‐ and para‐phenylene linkage ratios was synthesized by phosphorylation‐based polycondensation reaction of terephthalic acid (TPA) and/or isophthalic acid (IPA) with 3,4′‐oxydianiline (ODA) in NMP/CaCl2 solvent system. The synthesized PEA homopolymers and copolymers exhibited good solubility in organic polar solvents, such as NMP, DMAc and DMSO. The intrinsic viscosity of the synthesized PEAs in NMP solvent was measured to be in the range of 0.48‐0.97 dl/g. The 1H NMR analyses confirmed that the output compositions of PEA copolymers were quite consistent with the feed compositions. The photographic digital images and UV‐visible spectra showed that solution‐casted PEA films were optically light brown and transparent owing to their amorphous and nonlinear chain structures. The DSC data revealed that the glass transition temperatures of PEAs are in the range of 242–310 °C, depending on the relative contents of meta‐ and para‐phenylene linkages. All PEA films were characterized to be thermally stable up to ∼400 °C and to have high char residues above 63 % at 800 °C in nitrogen atmosphere.