Abstract: This invention relates to liquid crystalline polymers, having a glass transition temperature of greater than 140.degree. C., blended with tetrafluoroethylene polymers, said blends having improved wear properties.

Abstract: Polymeric blends of polyimide precursor resins and polyamides or polyesters, preferably in the form of liquid crystal polymers, provide polyimide products with excellent physical characteristics and injection molding capability.

Abstract: A melt-processable, miscible or partially miscible blend of an amorphous, isotropic polyarylate with a poly(ether ketone ketone) that does not possess a sharp or well defined melting endotherm by differential scanning calorimetry when observed on second heating under defined conditions can be extruded into sheets useful in aircraft panels and in other applications that require high burn resistance and good melt processability.

Abstract: Highly oriented sheets are prepared by hot pressing a warp of filaments of liquid crystal polymers and optionally heat strengthening.

Abstract: A process for improving the stability of a polyarylate resin by reducing the terminal carboxyl acid group concentration of the polyarylate resin, the process being comprised of melting a mixture of the polyarylate resin and an aromatic carbonate capping agent and reacting the mixture under heat and, if necessary, vacuum until the concentration of the terminal carboxyl acid groups is reduced to less than that of the polyarylate resin prior to end-capping. The process also results in a polyarylate resin with a decreased flammability rating when the aromatic carbonate capping agent is bromine substituted.

Abstract: Articles from filaments of thermotropic liquid crystal polymers are formed by pultrusion without use of extraneous binder, wherein the filaments formed in a bundle are essentially parallel to permit the greatest surface contact between adjacent filaments.

Abstract: Highly oriented sheets are prepared by hot pressing a warp of filaments of liquid crystal polymers and optionally heat strengthening.

Abstract: Thermoplastic polyarylate compositions having improved flame retardancy consisting essentially of polyacrylate, epoxy-containing polymer, brominated polystyrene and sodium antimonate.

Abstract: Use of magnetic particles coated with a dispersant to facilitate orientation of anisotropic melt-forming polymers in a magnetic field.

Abstract: The heat-strengthening of yarn spun from optically anisotropic melt-forming polyesters can be accelerated by coating the yarn prior to heat treatment with certain inorganic compounds.

Abstract: Heat treatment of shaped articles, larger than films or fibers, formed from anisotropic-melt-forming polymers provides an increase of at least 25% in energy to break in flexure. In at least one direction of measurement the heat treated articles are characterized by a flexural break strength of at least 10,000 psi, maximum strain to break in flexure of at least 2% and a flexural modulus of at least 500,000 psi. In many instances the heat treated articles can be further characterized by a notched Izod impact strength of at least 2 foot-pounds per inch.Since the heat-treated shaped articles have high levels of strength, stiffness and toughness, they are useful as replacements for some metals, e.g., brass.

Abstract: Fibers with enhanced tenacity are prepared by heat treating oriented fibers from anisotropic-melt-forming linear aromatic and cycloaliphatic polymers, especially polyesters (including copolyesters), while said fibers are essentially relaxed, at temperatures near the flow temperature but sufficiently below to prevent substantial interfilament fusion, for a period of from five seconds to several hours until the fiber tenacity is increased by at least 50% and to at least 10 grams per denier.