Novel cardo poly(arylene ether nitrile sulfone) copolymers bearing xanthene moiety in the main chain

A series of cardo poly(arylene ether nitrile sulfone) (PENS) copolymers containing xanthene moiety were prepared by the nucleophilic substitution reaction of 9,9-bis(4-hydroxyphenyl)xanthene with 2,6-difluorobenzonitrile (DFBN) and 4,4′-dichlorodiphenylsulfone (DCDPS) by varying stoichiometric ratio of DFBN to DCDPS (90/10–40/60) using N, N-dimethylacetamide (DMAc) as solvent in the presence of anhydrous potassium carbonate. The copolymers having number-average molecular weights of 17,100–18,300 g mol−1 with the polydispersity index from 1.79 to 2.11 were amorphous and were easily soluble in polar solvents such as N-methyl-2-pyrrolidone and DMAc, and even in tetrahydrofuran and chloroform at room temperature. The resulting PENS copolymers showed glass transition temperature ( Tg) between 253.3°C and 260.4°C, and the Tg values were found to increase with increasing sulfone content in the copolymers. Thermogravimetric studies showed that all the polymers were stable up to 450°C, with 10% weight loss temperatures ranging from 500°C to 524°C and char yields of 56–63% at 700°C under nitrogen atmosphere. All new polymers could be cast into strong and flexible films with tensile strengths of 56.7–78.8 MPa, elongations at break of 7.8–9.1%, and tensile moduli of 2.1–3.2 GPa.

Synthesis and characterization of soluble copoly(arylene ether ketone sulfone)s bearing xanthene moiety in the main chain

Several new poly(arylene ether ketone sulfone) (PEKS) copolymers containing xanthene moiety in the main chain were prepared by direct solution polycondensation reaction of 1,4-bis(4-fluorobenzoyl)benzene with varying mole ratios of 9,9-bis(4-hydroxyphenyl)xanthene and 4,4′-sulfonyldiphenol using sulfolane as solvent in the presence of anhydrous potassium carbonate. The introduction of xanthene and sulfone groups into the polymer chain resulted in an improvement in solubility of the polymers in common organic solvents such as N-methyl-2-pyrrolidone, N, N-dimethyl acetamide, sulfolane, pyridine, chloroform, and tetrahydrofuran. Thermal analysis revealed that the copolymers exhibited high glass transition temperatures ( Tgs) of 208–221°C and excellent thermal stability associated with 5% weight loss temperatures ranging from 490°C to 521°C and 62–66% residual weight at 650°C under nitrogen atmosphere. All copolymers were amorphous and their solubility increased with an increase of sulfone content in the polymer backbone, while the Tgs and overall thermal stability appeared to decrease slightly. This new kind of xanthene-containing PEKS copolymers may be considered a good candidate for using as high-performance structural materials.

Synthesis and properties of novel 9,9-diphenyl xanthene-based poly(aryl ether ketone)s with methyl substituents

A new bisphenol, 9,9-bis(4-hydroxy-3-methylphenyl)xanthene, was synthesized via a one-pot, two-step synthetic procedure in good yield and used for polymerization with difluorinated aromatic ketones in tetramethylene sulfone in the presence of anhydrous potassium carbonate to form several aromatic poly(ether ketone)s (PEKs) with 9,9-diphenylxanthene moieties and methyl substituents. The newly synthesized high-molecular-weight PEKs having number-average molecular weights in the range of 20,500–25,600 g mol−1 with the polydispersity index ranging from 1.9 to 2.1 were all amorphous and showed high glass transition temperatures in the range of 194–229.8°C, and the temperatures at the 5% weight loss were in the range of 420–445°C with char yields above 60% at 600°C under nitrogen atmosphere. All new PEKs are soluble in polar aprotic solvents, such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, chloroform, pyridine, m-cresol, and tetrahydrofuran, and could form transparent, strong, and flexible films with tensile strengths of 66–74 MPa, Young’s moduli of 2.47–2.77 GPa, and elongations at break of 8–14%. In addition, these polymers had high transparency with an ultraviolet–visible absorption cutoff wavelength in the 352–356 nm range and low moisture absorption in the range of 0.41–0.56%.

Synthesis and characterization of new poly(aryl ether ketone)s bearing (4-phenoxyphenyl)triphenylmethane moieties

1,1-Bis(4-hydroxyphenyl)-1-(4-phenoxyphenyl)-1-phenylmethane (BHPPPPM), a new bisphenol monomer, was synthesized with 65% yield from 4-benzoyl diphenyl ether in a one-pot, two-step synthetic procedure. Four new poly(aryl ether ketone)s (PAEKs) bearing (4-phenoxyphenyl)triphenylmethane moieties were prepared from BHPPPPM with four difluorinated aromatic ketones via a nucleophilic substitution reaction. The polycondensation proceeded in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the new PAEKs in nearly quantitative yields with inherent viscosities of 0.60–0.78 dL g−1. The resulting PAEKs having number-average molecular weights in the range of 29,500–34,200 g mol−1 with the polydispersity index ranged from 1.94 to 2.01 are all amorphous and show high glass transition temperatures ranging from 174°C to 196°C, excellent thermal stability, and the temperatures at the 5% weight loss are over 500°C with char yields above 60% at 700°C under nitrogen atmosphere. These new PAEKs 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 78–85 MPa, tensile moduli of 1.9–2.4 GPa, and elongations at break of 7–10%.