Phosphorylation‐assisted synthesis and characterization of poly(3,4'‐oxydiphenylene furanamide) as a wholly aromatic polyamide using biomass‐derived 2,5‐furandicarboxylic acid

Abstract We report the phosphorylation‐assisted polymerization and characterization of 2,5‐furandicarboxylic acid (FDCA)‐based wholly aromatic polyamide. For this purpose, poly(3,4′‐oxydiphenylene furanamide) (PODFA) was synthesized via solution polymerization of FDCA with 3,4′‐oxydiphenylamine (ODPA) in the presence of triphenyl phosphite and pyridine. The spectroscopic analyses and solution viscosity measurement revealed the successful synthesis of a relatively high molecular weight PODFA with good solubility in a variety of polar aprotic solvents without inorganic salts. PODFA could be thus processed into purely amorphous films with high flexibility in bending and folding deformation. The 39 μm thick PODFA film exhibited optical transparency, and the 65–100 μm thick films showed a transparent yellow or light brown color. The amorphous PODFA films were characterized to have excellent thermal and static mechanical properties in terms of a glass transition temperature of ~260°C, a thermal decomposition peak temperature of ~450°C, a residue of ~50% at 800°C under nitrogen gas condition, an initial modulus of 12.98 ± 1.84 GPa, a tensile strength of 84.6 ± 17.3 MPa, and a strain at break of 2.3 ± 1.5% at room temperature.