Synthesis and Characterization of Novel Soluble Cardo Poly(arylene ether ketone)s Containing Xanthene Structures

9,9-Bis(4-hydroxyphenyl)xanthene (BHPX), a bisphenol monomer, was synthesized in 82% yield from xanthenone in a one-pot, two-step synthetic procedure. Four novel aromatic poly(ether ketone)s (PEKs) based on BHPX were prepared via a nucleophilic aromatic substitution polycondensation with four difluorinated aromatic ketones. The polycondensation proceeded in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the new cardo PEKs in nearly quantitative yields with inherent viscosities of 0.77-0.85 dL/g. High molecular weight PEKs having number-average molecular weights (M(n)'s) in the range of 38,900-40,600 g/mol with the polydispersity index ranged from 1.97 to 2.06 are all amorphous and show high glass transition temperatures ranging from 210 degrees C to 254 degrees C, excellent thermal stability, and the temperatures at the 5% weight loss are over 538 degrees C with char yields above 60% at 700 degrees C in nitrogen. These new PEKs are all soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone and N, N'-dimethylacetamide and could also be dissolved in chloroform and tetrahydrofuran. All the polymers formed transparent, strong, and flexible films with tensile strengths of 78-84 MPa, Young's moduli of 2.54-3.10 GPa, and elongations at break of 14-18 %. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 570-576, 2009