Abstract: Asymmetric hollow fibers of SIXEF.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These uncoated fibers have a separation factor that exceeds 4 for oxygen and nitrogen and a permeance of at least about 50 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ("NMP") and an organic acid such as propionic acid ("PA") is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to the organic acid. The dope is wet-spun into hollow fibers using a core solvent such as PA or glycerine; the fibers are coagulated in water.

Abstract: A miscible blend comprising from about 5 to about 95 weight percent of a polybenzimidazole and from about 95 to about 5 weight percent of a polyamide-imide having fluorine-containing linking groups, total weight percent of the two polymers being 100. A process for preparing the blends comprises dissolving in a mutual solvent from about 5 to about 95 weight percent of the aromatic polybenzimidazole to about 95 to about 5 weight percent of the polyamide-imide having fluorine-containing linking groups, based on the total weight of those polymers and subsequently evaporating the solvent, thereby producing a dried blend of a polybenzimidazole and a polyamide-imide having fluorine-containing linking groups. The blends, particularly in the form of films, fibers or fibrets, may be post-treated with heat or sulfuric acid in order to minimize their shrinkage when subsequently subjected to heat and in order to increase their resistance to solvents and acid.

Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein R is CF.sub.3 or a phenyl radical. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, good resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as good thermal properties, including resistance to thermooxidative degradation.

Abstract: The present invention provides for hybrid polybenzimidazole and polybenzimidazolone polymers which are characterized as containing both imidazole and imidazolone structural units in the polymer chain. These polymers are characterized as containing at least one recurring monomer unit containing the structure of the formula: ##STR1## wherein Ar is a tetravalent aromatic moiety derived from an aromatic tetraamine and Ar.sub.1 is a trivalent aromatic moiety derived from a trifunctional acid, an acid anhydride or amine-reactive derivatives thereof, said polymers further characterized by an inherent viscosity of at least about 0.01 dl/g measured as a 0.5% solution in N-methyl pyrrolidone at 25.degree. C.The polymers of this invention exhibit many of the advantageous properties of both polybenzimidazole and polybenzimidazolone polymers. They are characterized as being extremely resistant to chemical attack such as by solvents, acids and bases.

Abstract: Novel polyimide blends are formed of polyimide polymers each having moieties derived from dianhydride and diamine comonomers. The blends of the present invention may be formed by selecting polyimide polymers having structurally identical dianhydride-derived moieties, but structurally different diamine-derived moieties. Preferred miscible blends are formed wherein one of polyimides in the blend is the polymer condensation product of a dianhydride selected from 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl ether dianhydride, pyromellitic dianhydride, and mixtures thereof, and 2,2-bis(3-aminophenyl) hexafluoropropane, and another of the polyimides in the blend is the polymer condensation product of the same dianhydride and mixtures thereof noted above, and 2,2-bis(4-aminophenyl) hexafluoropropane.

Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines, one or more additional comonomers selected from the group consisting of a tetrafunctional aromatic dianhydride, an aromatic or aliphatic dicarboxylic acid (or acid derivative thereof) and mixtures thereof, and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein Z is CF.sub.3 or a phenyl radical.

Abstract: The present invention provides cross-linkable polyimide polymers having at least one repeating unit of the sturcture of: ##STR1## wherein n is the number of repeating groups and A is a tetravalent aromatic organic radical wherein each pair of carbonyl groups are attached to adjacent carbons in the ring moiety A.It has been found that polyimides having the structure of formula I may be crosslinked at surprisingly low temperatures when heated from about 75 to about 110.degree. C. to form infusible and solvent resistant shapes, thereby rendering them useful in the preparation of films, laminates and composites where inertness to solvents is a prerequisite.

Abstract: New polybenzimidazolone polymers produced from the reaction of an aromatic tetraamine with a hexafluoro dianhydride. These hexafluoro polybenzimidazolone polymers based on an aromatic hexafluoro dianhydrides show improved solubility, easy processability, low moisture uptake, high thermal stability, resistance to solvent and other improvements over conventional polybenzimidazolone polymers.

Abstract: This invention discloses new polybenzimidazolone polymers produced by the reaction of a hexafluoro aromatic tetraamine with a dianhydride reactant. These hexafluoro polybenzimidazolone polymers based on an aromatic hexafluoro tetraamine show improved solubility, easy processability, low moisture uptake, high thermal stability, resistance to solvent and other improvements over conventional polybenzimidazolone polymers.

Abstract: Polyimides and polyamide-acids having improved solubility and processing characteristics and high glass transition temperatures are provided, having incorporated into the polymeric chain the novel aromatic dianhydride compound 4,4'-bis[2-(3,4-dicarboxyphenyl) hexafluoroisopropyl] diphenyl dianhydride. The polyamide-acids and polyimides are prepared by reacting the 12F-Diphenyl DA with aromatic or aliphatic diamines. It has been found that the polyimides of this invention have improved solubility characteristics, good dielectric properties while at the same time exhibiting relatively high glass transition temperatures, and superior thermal and thermo-oxidative stability. The polymers may be processed into films, fibers or compression molded or fabricated into composites at moderate temperatures and pressures.

Abstract: This invention relates to new fluorine-containing polyimides, polyamide-acids/esters, polyamides, addition polyimides and imide oligomers which exhibit low melting points, better solubilities, low dielectric constants, superior thermal and thermal oxidative stability, and improved processing characteristics.The products of this invention are characterized by the fact that they are derived from 4,4'-bis[2-(3,4-(dicarboxyphenyl)hexafluoroisopropyl]diphenyl ether dianhydride.

Abstract: This invention relates to new fluorine-containing polyimides, polyamide-acids/esters, polyamides, addition polyimides and imide oligomers which exhibit low melting points, better solubilities, low dielectric constants, superior thermal and thermal oxidative stability, and improved processing characteristics.The products of this invention are characterized by the fact that they are derived from 4,4'-bis[2-(amino(halo)phenoxyphenyl)hexafluoroisopropyl]diphenyl ether.

Abstract: A novel composition consisting essentially of a polyimide of the formula: ##STR1## wherein R is: ##STR2## is disclosed and claimed. The composition has a weight average molecular weight, M.sub.w of at least 75,000 and a polydispersity of from about 1.8 to about 2.6.

Abstract: Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.

Abstract: High molecular weight polyimides are formed by polycondensation of 2,2-bis(4-aminophenyl) hexafluoropropane or 2,2-bis(3-aminophenyl) hexafluoropropane with one or more of bis-(3,4 dicarboxyphenyl) ether dianhydride; 3,3', 4,4' benzophenone tetracarboxylic acid dianhydride; 3,3', 4,4' diphenyl tetracarboxylic acid dianhydride and 2,2-bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride. Generally, the polymers of the present invention are characterized by a molecular weight of more than about 90,000.

Abstract: Polyimides and polyamide-acids having improved solubility and processing characterisitcs are provided having incorporated into the polymeric chain as a novel aromatic diamine compound, 2-(3-aminophenyl)-2-(4-aminophenyl) hexafluoropropane (3,4'-6F Diamine). The polyamide-acids and polyimides are prepared by reacting the 3,4'-6F Diamine with aromatic tetracarboxylic acids or anhydrides thereof. It has been found that the polyimides of this invention have improved solubility characterisitics, low dielectric constants and improved thermal flow properties as a consequence of the meta/para positioning of the amino groups on the diamine, which renders these polymers more readily melt spinnable for the production of fibers. The polymers may also be compression molded and fabricated into composites at moderate temperatures and pressures. Solutions of the polyimides may be cast into films.

Abstract: Polyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine and pyromellitic dianhydride (PMDA) can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride (ODPA), 3,3'4,4' benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4' diphenyl tetracarboxylic acid dianhydride (BPDA) and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.

Abstract: The present invention provides novel heat stable polyimide and polyamic acid precursor polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more aromatic dianhydride monomers, at least one of said diamine monomers having the structure: ##STR1## wherein R is CF.sub.3 or phenyl. The polyimides of this invention exhibit improved solubility and low temperature flow characteristics, low moisture uptake, high thermal stability, low dielectric constant and good hydrolytic stability.

Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, wherein at least one of said diamine monomers is a 12F-Diamine or 12F-Oxydiamine containing at least two CF.sub.3 ##STR1## R groups linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degredation.

Abstract: The present invention provides novel heat stable polyamide polymer having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more aromatic dibasic acid monomers or amide-forming derivatives thereof, at least one of said diamine monomers having the structure: ##STR1## where R is CF.sub.3 or phenyl. The polyamides of this invention exhibit improved solubility and low temperature flow characteristics, low moisture uptake, high thermal stability, low dielectric constant and good hydrolytic stability.