Synthesis and characterization of soluble aromatic poly(ether amide amide ether ketone ketone)s by electrophilic Friedel-Crafts solution polycondensation

A new monomer, N,N′-bis(4-phenoxybenzoyl)-m-phenylenediamine (BPBMPD), was prepared by condensation of m-phenylenediamine with 4-phenoxybenzoyl chloride in N,N-dimethylacetamide (DMAc). Novel soluble aromatic poly(ether amide amide ether ketone ketone)s (PEAAEKKs) were synthesized by electrophilic Friedel-Crafts solution copolycondensation of BPBMPD with a mixture of terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC) in the presence of anhydrous aluminum chloride and N-methylpyrrolidone (NMP) in 1,2-dichloroethane (DCE). The influences of reaction conditions on the preparation of polymers were examined. The polymers obtained were characterized by different physico-chemical techniques such as FT-IR, DSC, TGA, and wide-angle X-ray diffraction (WAXD). All the polymers were amorphous and the solubility of the polymers was improved by the incorporation of 1,3-dibenzoylaminobenzene moieties in the main chain. Thermal analyses showed that the polymers had high Tgs of 220-231 °C and exhibited high thermal stability. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 102.9-108.5 MPa, Young's moduli of 2.44-2.86 GPa, and elongations at break of 9.8-13.7%.