Abstract: Blends of thermotropic liquid crystalline polymers and isotropic melt-processable polymers are made by extruding a molten stream of either a thermotropic liquid crystalline polymer or an isotropic polymer through a heated mixing zone and feeding the other of the two polymers into the stream of the first polymer in the mixing zone. The polymers are mixed under shearing conditions for a time sufficient to yield a uniform blend. Blends made according to this method exhibit improved properties in comparison with blends obtained by feeding the two polymers simultaneously into a heated mixing zone.

Abstract: Provided is an injection moldable composition suitable for forming ceramic or metallic greenbodies. The composition comprises in combination an inorganic or metallic filler in an amount of from about 63 volume percent to about 92 volume percent, a binding organic matrix resin, and an organosilane processing reagent represented by the general formula:SiX.sub.1 X.sub.2 X.sub.3 X.sub.4wherein at least one of X.sub.1, X.sub.2, X.sub.3 or X.sub.4 is an unfunctionalized alkyl or alkenyl group having 10 to 35 carbon atoms and at least one of X.sub.1, X.sub.2, X.sub.3 or X.sub.4 is an alkoxy group or halide, such that the moldable composition exhibits a low initial mixing torque upon mechanical agitation. These compositions offer excellent advantage in processibility using conventional mixing and molding equipment.Also provided is a process for preparing the moldable compositions.

Abstract: A copolymer consisting essentially of a repeating sequence represented by the formula ##STR1## where Ar.sub.1, Ar.sub.2, and Ar.sub.3, are each independently chosen from the group consisting of ##STR2## which are either unsubstituted or are substituted with one or more substituents chosen from the group consisting of alkyl groups having 1-6 carbon atoms, halogen (F, Cl or Br), and phenyl; Z, Y.sub.1 and Y.sub.2 are each independently O, NH, or S; n and m are positive integers; and X is a covalent bond, O, S, SO.sub.2, CO, C(C.sub.6 H.sub.5).sub.2, C(C.sub.6 H.sub.5)H, C(C.sub.6 H.sub.5)(CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3)H, CH.sub.2, C(CF.sub.3).sub.2, or 3,3,5-trimethyl cyclohexyl. The polymers of this invention are derived from a minimum of three different monomers.

Abstract: A new class of thermotropic liquid crystalline polymers comprises monomers units I, II, III, and IV, where ##STR1## Ar.sup.1, Ar.sup.2 and Ar.sup.3 are each independently selected from the group consisting of 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 2,7-naphthylene, 4,4'-biphenylene, bis-aryl moieties having the formula ##STR2## and mixtures thereof. In the bis-aryl moieties, each X can be S, O, CO, SO, SO.sub.2, C(CH.sub.3).sub.2 or C(CF.sub.3).sub.2.

Abstract: A melt processable poly(ester-amide) which is capable of forming an anisotropic melt phase is provided. A poly(ester-amide) of the present invention may have recurring units of: (a) 4-hydroxybenzoyl moiety, (b) 6-oxy-2-naphthoyl moiety, (c) 4,4'-biphenol moiety, (d) terephthaloyl moiety, and (e) an aromatic moiety capable of forming an amide linkage in the proportions indicated. Preferably, the moiety capable of forming an amide linkage is derived from p-aminophenol, p-phenylenediamine, N-acetyl-p-aminophenol, etc. The resulting poly(ester-amide) is capable of undergoing melt-processing in the temperature range of from about 300.degree. to about 400.degree. C.

Abstract: A novel curing process for preceramic organosilicon polymers is disclosed which involves contact with a gaseous hydrogen halide.

Abstract: A method is disclosed of preparing amidated water soluble cellulose acetates by amidating water soluble cellulose acetate. Methods are also provided for preparing aminated water soluble cellulose acetates of varying plasticities, film- and fiber-forming characteristics, and other properties by methanolysis of naturally-occurring chitin or by amination of water soluble cellulose acetate.

Abstract: Asymmetric fluoropolymer hollow fibers having a thin, dense, inner separation layer that is essentially defect-free. In the process of this invention, a fluoropolymer dope is spun into a hollow fiber using a hollow fiber die, a core solvent, preferably comprising water, and a coagulation bath, preferably comprising a water-acetone mixture. Due to solubility and surface tension differences, the outer layer of the fiber does not coagulate quickly enough to form a dense layer, and remains porous, but the core solvent causes the inner surface of the hollow fiber to coagulate into a thin, dense, defect-free layer.

Abstract: A paint remover composition consisting essentially of a single phase mixture of water, trioxane and an organic co-solvent having a flash paint above about 80.degree. C. is disclosed and claimed. Particularly preferred co-solvents are gamma-butyrolactone and N-methyl pyrrolidone.

Abstract: Vibration damping composites suitable for use in construction panels or constrained-layer elements are described. The composites include a viscoelastic gel prepared from 99.5-92.5 wt. % water and 0.5-7.5 wt. % of a superabsorbent polymer. Preferably, the polymer is of the carboxylic acid type and optionally includes starch or cellulose.

Abstract: High to ultrahigh polyester compositions comprising monomer units derived from 2,6-naphthalenedicarboxylic acid, 4,4'-bibenzoic acid and ethylene glycol are useful as fibers and molding resins when the mole ratio of 4,4'-bibenzoic acid to 2,6-naphthalenedicarboxylic acid is from about 60:40 to about 40:60, and especially when the two diacids are included in about equimolar amounts. These compositions yield fiber with excellent tensile properties, both at room temperature and at elevated temperatures. When these compositions are melt spun at a relatively low melt temperature and high draw down ratio, fibers with excellent tensile properties are obtained without a subsequent drawing step.

Abstract: Disclosed is a process for blow molding articles from liquid crystal polymers containing ionic moieties in the backbone. The ionic moieties increase the melt viscosity of the polymers sufficiently high to blow mold articles therefrom. An illustrative liquid crystal polymer is made from 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and sodium 5-sulfoisophthalate.

Abstract: Compounds useful as polymer stabilizers which are polymerizable into condensation polymer systems are disclosed and claimed. A particularly preferred embodiment is 1-(3'-(benzotriazol-2"-yl)-4'-hydroxyphenyl)-1,1-bis(4-hydroxyphenyl)ethan e.

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 crosslinked elastomeric acetal polymer is synthesized from 1,3-dioxolane, 1,3-dioxepane, and a polyfunctional crosslinking compound having two or more functional groups that react under conditions of cationic polymerization, such as 1,4-divinyloxybutane or poly(butadiene oxide). The polymers are elastomeric and non-crystalline at temperatures well below room temperature. They can be blended with crystalline acetal polymers to produce blends that have improved impact properties.

Abstract: There is disclosed and claim a multi-layer polymeric optical element including at least two poled film members exhibiting nonlinear optical susceptibility. The films may be poled in an ordinary atmosphere under relatively mild conditions, or corona poled at high voltage. The elements are particularly useful for periodic or quasi-random optical applications such as parametric amplification of light or frequency doubling.

Abstract: An improved liquid crystalline polymer blend is produced by mixing a preformed thermotropic liquid crystalline polymer in the melt phase with reactants needed to form a second liquid crystalline polymer under conditions sufficient to form the second liquid crystalline polymer. The resulting blends are anisotropic and have improved morphology and improved melt processability. The method is particularly useful when the second liquid crystalline polymer is biphasic or is difficult to synthesize or process in the melt.

Abstract: A polymeric composition containing internal lubricants is suitable for low friction applications. The composition contains from about 65 to about 85 weight percent of a polymeric blend and from about 15 to about 35 weight percent of internal lubricants, wherein said blend consists essentially of from about 35 to about 100 weight percent of polybenzimidazole and from about 0 to about 65 weight percent of poly(aryletherketone), and said lubricants consist essentially of graphite and boron nitride in a weight ratio of about 1:10 to about 10:1, respectively. The composition is useful for preparing shaped articles such as bearings, bearing sleeves, rings, etc.

Abstract: A compactible polybenzimidazole composition contains from about 95 to about 5 weight percent of solid lubricant particles which are uniformly dispersed and encapsulated in from about 55 to about 95 weight percent of polybenzimidazole. The solid lubricant comprises graphite and boron nitride in a weight ratio of about 10:1 to about 1:10. The composition is useful for preparing self lubricating, shaped articles such as bearings, bearing sleeves, rings, seals, etc. which exhibit low friction properties.

Abstract: A breathable water-resistant fabric in which a surface of a fabric material is coated with a microporous layer of ETFE, and a process for making same. An ETFE dope containing a blend of ETFE and a binder polymer is cast or extruded into a film which is subsequently bonded or laminated to the fabric material. The binder is extracted to produce a microporous ETFE layer.