Synthesis and characterization of poly[[1,1′-biphenyl]-4,4′-diyl[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]]

A new high-performance material, poly[[1,1'-biphenyl]-4,4'-diyl[2,2,2-trifluo-romethyl)ethylidene]] (PDTFE), was prepared by Ni(O)-catalyzed coupling of 2,2-bis(p-chlorophenyl)hexafluoropropane. The resulting high molecular weight polymer ((M) over bar(n) of 19.2 x 10(3) g/mol by gel permeation chromatography and 27.5 x 10(3) g/mol by multiple-angle laser Light scattering) is amorphous and soluble in a number of common organic solvents including tetrahydrofuran, chloroform, and acetone. The solubility leads to ease of preparation, characterization, and processing of PDTFE. Excellent thermal properties were exhibited with a glass transition temperature of 255 degrees C and 10% weight loss values of 553 and 535 degrees C in nitrogen and air, respectively. The flame-retardant properties showed that the material meets the Federal Aviation Administration's current criteria for heat release capacity, total heat release, and char yield for name-retardant materials. Additionally, colorless, transparent, creasable films were cast from chloroform. The film formation of PDTFE made the gas permeability measurements possible. PDTFE has a rather high oxygen permeability coefficient of 120 x 10(-10) cm(3) (STP)cm/(cm(2).s.cmHg) and an O-2/N-2 selectivity of 2.9 at 35 degrees C. The new material has an impressively low dielectric constant of 2.56. Finally, the new polymer is highly hydrophobic with no detectable water uptake after 24 h in boiling water. The combination of facile synthesis and an excellent property profile makes this a unique phenylene-based high-performance polymer that will lead to a series of novel fluorinated materials.