Abstract: Refrigerants, such as Freon.RTM. 12 and other potential ozone depleting substances will be in short supply as their production is phased out, and until existing refrigeration equipment is retrofitted to receive more environmentally friendly refrigerants. Existing supplies of such refrigerants when contaminated with other refrigerants especially hydrofluoroalkanes like Freon 22 can form azeotropes, which are not readily separated by conventional distillation methods, are selectively decomposed in-situ by reacting with aqueous solutions of metal hydroxides or other bases. The remaining non-reacted refrigerant-containing composition is readily recycled by separation and recovery methods from the reaction mixture to provide a reusable refrigerant composition virtually free of contaminating refrigerant.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %. in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.

Abstract: Layered substrates are disclosed having an ultra-smooth surface finish thereon rendering them useful in making high density magnetic storage media. The layered substrates are comprised of a non-oxide ceramic core coated with a smoothing layer comprised of an amorphous metal, particularly certain amorphous metal alloys based on chromium, molybdenum, tungsten, and mixtures thereof. Also disclosed are magnetic storage media comprising the layered substrates, as well as processes for making the substrates and magnetic media.

Abstract: Substrates are disclosed having an ultra-smooth surface finish thereon rendering them useful in making high density magnetic storage components, such as a computer hard disk or thin-film head which can read and/or write data on such disks. The substrates are comprised of a non-oxide ceramic base which is coated with a smoothing layer comprised of amorphous, non-stoichiometric silicon carbide corresponding to the formula SiC.sub.x, wherein x is the molar ratio of carbon to silicon and is greater than 1. Also disclosed are processes for making the substrates and components.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %. in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.

Abstract: A predominantly .beta.'-sialon-bonded silicon carbide refractory article is produced by reaction-nitriding a green body containing a plurality of silicon carbide powders, none having an average particle size greater than about 200 micrometers, a metal oxide oxygen source, fine grained silicon, and a source of aluminum. The invention also includes a raw batch and a process for producing the refractory article.

Abstract: This invention provides a reaction-bonded silicon carbide article having superior abrasion resistance, oxidation resistance and uniformity in which the bond phase comprises appreciable amounts of both silicon oxynitride and alumina. Also provided are a raw batch and a process for producing the reaction-bonded article.

Abstract: A catheter retainer which includes a flexible flattened pad, a tunnel sized to pass the catheter extending transversely through the pad and a slit on the back face of the pad, following the tunnel, for insertion of the catheter, together with a method for using the catheter retainer.

Abstract: The invention provides a tissue perfusion catheter which includes a tightly wound coil spring having an exterior, fluid impervious sleeve extending from a proximal end up to a distal portion of the spring which terminates at a sealed distal tip. Connection of the proximal end of the catheter to a source permits perfusion of diseased tissue with a therapeutic fluid which oozes at a low rate from the unsealed distal portion, while avoiding tissue ingrowth tending to plug the catheter. Various combinations which include the catheter are also provided as are methods for its use.

Abstract: The invention provides a silicon carbide fiber carrying an aluminum nitride coating between about 1 and about 15 micrometers thick. The AlN coating serves as a debond layer which improves the fracture toughness of composite materials in which the coated fiber is a reinforcement phase.

Abstract: A flexible, resilient, intumescent mat material comprising fiber, binder, and an intumescent agent which includes a mixture of unexpanded vermiculite and expandable graphite undergoes intumescence at a lower temperature, with an enhanced degree of expansion and with a lesser degree of contraction upon prolonged heating. The intumescent mat can be employed in catalytic converters for motor vehicles and as a firestop material.

Abstract: This invention provides a reaction-bonded silicon carbide article having superior abrasion resistance, oxidation resistance and uniformity in which the bond phase comprises appreciable amounts of both silicon oxynitride and alumina. Also provided are a raw batch and a process for producing the reaction-bonded article.

Abstract: This invention is directed to substantially strain-free, shaped, sintered ceramic fabric preform segments, to the production of the sintered preform segments from novel fixtured, shaped, green ceramic fabric preforms, and to sintered ceramic fiber-reinforced composite articles prepared from the sintered preforms and characterized in that the reinforcement phase is substantially free of mechanical strain, and the fiber in the fabric can exhibit a very small bending radius.

Abstract: A flexible, resilient, intumescent mat material comprising fiber, binder, and an intumescent agent which includes a mixture of unexpanded vermiculite and expandable graphite undergoes intumescence at a lower temperature, with an enhanced degree of expansion and with a lesser degree of contraction upon prolonged heating. The intumescent mat can be employed in catalytic converters for motor vehicles and as a firestop material.

Abstract: An improvement in the process for making a dialkyl phosphorochloridothioate from P.sub.2 S.sub.5, alkyl alcohol and chlorine in which the desired product is separated from the reaction mixture by distillation, leaving an unstable, acidic residue, wherein the residue is stabilized and neutralized by reaction with an organic base, thereby enhancing the value of the residue while avoiding potential environmental damage caused by disposal of the residue.

Abstract: A refractory tile adapted for protective fixation to the heat exchanger in an incinerator or furnace regardless of orientation. The tile includes a transverse groove which carries a shouldered slot to be guided by and mate securely with an anchor attached to the heat exchanger.

Abstract: A self-supporting film of a curable fluorine-containing aromatic polyimide precursor resin is applied to and cured at elevated temperature and pressure on one or more outer surfaces of a reinforced substrate. The substrate is (1) a prepreg lay-up of (a) reinforced plies of a curable aromatic polyimide precursor or (b) fibers impregnated with a cured polyimide powder, or (2) a composite previously formed by curing a lay-up of a reinforced plies of a curable aromatic polyimide precursor. The resultant cured coating improves the erosion resistance of the composites so formed. Use of such films avoids the difficulties experienced when using conventional spray coating procedures.

Abstract: A novel flame retardant formulation comprising a flammable macromolecular material and a metal salt of a polybrominated sulfonic acid and having improved flame retardancy and enhanced U.V. stability.

Abstract: The quality of a product predominant in tetrabromobisphenol-A is enhanced by heat treating the product for a period of time and at a temperature which are sufficient to obtain a TBBPA predominant product having less than about 50 ppm of hydrohalide impurities.

Abstract: Polyorganophosphazenes having at least some N-(acryloxyhydrocarbyl)ureidohydrocarbyloxy groups: ##STR1## bonded to an oxygen substituted on at least some of the phosphorus atoms of the phosphazene chain. These compounds can be cross-linked by exposure to ultraviolet radiation.