Synthesis of new fluorinated aromatic poly (ether ketone amide)s containing cardo structures by a heterogeneous palladium-catalyzed carbonylative polycondensation

摘要

New fluorinated aromatic poly (ether ketone amide)s containing cardo structures were prepared by a heterogeneous palladium-catalyzed polycondensation of fluorinated aromatic diiodides with ether ketone units, aromatic diamines containing cardo groups, and CO. Polymerizations were conducted in N,N-dimethylacetamide at 120 degrees C using 6 mol% of magnetic nanoparticles-supported bidentate phosphine palladium (II) complex [Fe3O4@SiO2-2P-PdCl2] as catalyst and 1,8-diazabicyclo[5,4,0]-7-undecene as base and resulted in fluorinated cardo poly (ether ketone amide)s with inherent viscosities up to 0.75 dL/g. All the polymers were readily soluble in many organic solvents and could afford transparent, flexible, and strong films by solution casting. These polymers showed good thermal stability with the glass transition temperature of 237 degrees C-258 degrees C, the temperature at 5% weight loss of 462 degrees C-477 degrees C in nitrogen. These polymer films also exhibited good mechanical properties, excellent electrical and dielectric performance, and high optical transparency. The incorporation of bulky fluorinated groups and cardo structures into polymer backbone has played an important role in the improvement of solubility, dielectric performance, and optical properties. Importantly, the heterogeneous palladium catalyst can easily be recovered from the reaction mixture by simply applying an external magnet and recycled up to 7 times without significant loss of catalytic activity.