Abstract: Disclosed are rigid fluorinated monomers 9-phenyl-9-perfluoroalkylxanthene ##STR1## . The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: Rigid fluorine-containing compounds, monomers, and polymers based on pentacyclic core systems, such as 12H,14H-5, 7-dioxapentacene with perfluoroalkyl and/or aryl groups in the 12, 14 positions, and 5H,12H-7, 14-dioxapentacene, with perfluoroalkyl and/or aryl groups in the 5,12 positions. These monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides. The rigid pentacyclic core decreases the coefficient of thermal expansion of the polymers, while the fluorinated substituents improve the dielectric constant and water absorption properties. Each monomer unit contains within its pentacyclic core two-O-bridges, and two --CRR.sub.f bridges (where R is aryl, substituted aryl or perfluoroalkyl, and R.sub.f is perfluoroalkyl).

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis-(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoro-alkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis-(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: The present invention relates to multistep syntheses of hexafluoropropylene from hexachloropropylene. In all these syntheses the first step is a fluorination of the starting material; later steps convert the initial products to CF.sub.3 --CFCl--CF.sub.3, which is dehalogenated to the desired product.

Abstract: The present invention relates to multistep syntheses of hexafluoropropylene from acyclic three-carbon hydrocarbons or partially halogenated acyclic three-carbon hydrocarbons. In all these syntheses the first step is a vapor-phase chlorofluorination of the starting material to one or more saturated chlorofluorocarbons. Novel catalysts are also provided.

Abstract: Disclosed are rigid fluorinated monomers, their preparation, and polymers derived therefrom based on two novel tricyclic xanthene core systems, 9,9-bis(perfluoroalkyl)xanthene (I) and 9-phenyl-9-perfluoroalkylxanthene (II). The monomers have utility in the preparation of advanced high-performance polymers, particularly polyimides.

Abstract: The present invention relates to multistep syntheses of hexafluoropropylene from propane, propylene or partially halogenated acyclic three-carbon hydrocarbons. In all these syntheses the first step is a vapor-phase chlorofluorination of the starting material to the unsaturated chlorofluorocarbon CF.sub.3 CClCCl.sub.2.