Novel polyaryletherketones bearing pendant carboxyl groups and their rare earth complexes, Part I: Synthesis and characterization

A series of novel polyaryletherketones bearing pendant carboxyl groups were synthesized via solution nucleophilic polycondensation reaction, and the rare earth (Re3+ = Sm3+, Eu3+, Dy3+ and Tb3+) coordinated polymers were prepared using the polymer as macromolecular ligand and 1,10-phenanthroline (Phen), dibenzoylmethane (DBM) or 8-hydroxyquinoline (HQ) as co-ligands. Their structures were confirmed by means of FT-IR, 1H NMR and WAXD methods. WAXD results showed that the rare earth-coordinated polymer had similar amorphous structure to the polymer matrix, whereas the diffraction peaks corresponding to rare earth salts were completely absent, indicating a homogeneous distribution of rare earth ions within the polymer hostess due to the formation of coordination bonds between rare earth ions and the carboxyl groups on the polymer backbone. The rare earth coordination polymers were soluble in polar solvents such as DMSO, DMAc, DMF and NMP, and could be easily cast into transparent tough thin films. The polyaryletherketones synthesized had high glass transition temperatures above 210 °C, and showed fairly good thermal stability with 5% thermal decomposition loss above 402 °C.