Abstract: Copolymers of perfluoro(1,3-dimethyl-2,2-dioxole) with perfluoro(butenyl vinyl ether) and, optionally, with a third comonmer are amorphous in all monomer proportions, and soluble in perfluoro(2-butyl tetrahydrofuran). These copolymers are suitable in many high technology applications, especially where solubility is important, e.g., in applying coatings to substrates or articles for protection against mechanical, chemical, or environmental hazards. Dipolymers of the present invention have lower glass transition temperatures than dipolymers of perfluoro(1,3-dimethyl-2,2-dioxole) with tetrafluoroethylene having the same monomer proportions.

Abstract: A method of protecting machine-readable markings on the surfaces of articles consisting in applying to the machine-readable markings a thin layer of an amorphous fluoropolymer, which may be, i.a., a copolymer of perfluoro(1,3-dioxole) or of perfluoro(2,2-dimethyl-1,3-dioxole) with a fluoromonomer selected from a specifically recited group, especially, with tetrafluoroethylene; or a cyclic aliphatic homopolymer in which the repeating unit contains an aliphatic ring of 5-9 members at least two of the ring members being carbon atoms independently substituted either by fluorine atoms or by perfluoromethyl groups, at most two of the ring atoms being oxygen atoms, the remaining portions of the repeating units when present, being pefluoromethylene groups.

Abstract: Blends of polyvinyl chloride with E/X/Y terpolymers, in which X is a C.sub.1 -C.sub.10 n-alkyl acrylate and Y is CO or SO.sub.2, the terpolymers having a swelling ratio of no more than 2.14, can be calendered into smooth sheets, which are suitable for use in such applications as instrument panel skins, pond liners, roofing membranes, etc.

Abstract: The viscosity stability of a copolymer of ethylene with at least one comonomer which is an ethylenically unsaturated carboxylic acid is improved by exposing the isolated copolymer to moisture for a sufficient period to cause the copolymer to retain at least 20 weight percent more water than it would retain if it were purged with air or nitrogen heated to a temperature at least 5.degree. C. above ambient, which air or nitrogen has not been humidified after it has been heated to such temperature.

Abstract: Copolymers of perfluoro(1,3-dimethyl-2,2-dioxole) with perfluoro(butenyl vinyl ether) and, optionally, with a third comonmer are amorphous in all monomer proportions, and soluble in perfluoro(2-butyl tetrahydrofuran). These copolymers are suitable in many high technology applications, especially where solubility is important, e.g., in applying coatings to substrates or articles for protection against mechanical, chemical, or environmental hazards. Dipolymers of the present invention have lower glass transition temperatures than dipolymers of perfluoro(1,3-dimethyl-2,2-dioxole) with tetrafluoroethylene having the same monomer proportions.

Abstract: A process for melt-blending a polyamide with a crystalline polyolefin incompatible therewith in the presence of a rubbery compatibilizing polymer capable of chemically or physically associating with both the polyamide and the polyolefin, at a process temperature higher than the highest melting temperature of any crystalline polymer present and higher than the highest glass transition temperature of any amorphous polymer present but such that significant degradation of any polymer present does not occur, all blend components being present within stated ranges, and the melt viscosity ratio of the polyamide to that of the polyolefin at the process temperature and a shear rate of about 100-200 sec.sup.-1 being about 0.1-1.2, especially 0.4-0.8. High stiffness, supertough polymer blends, where notched Izod impact strength exceeds 535 J/m, are obtained.

Abstract: Formaldehyde and/or methylal are made by the electrooxidation of methanol in an apparatus which is divided into the anode compartment and the cathode compartment by a cationic membrane made of a fluoropolymer and having pendant fluorosulfonyl or sulfonic acid groups, which is coated on one side with platinum applied by the impregnation-reduction method, said coating serving as the anode. The cathode may be a metal layer on the opposite side of the membrane or a separate metal cathode. When the separate metal cathode is employed, the cathode compartment contains a liquid electrolyte, which is a concentrated inorganic acid, preferably phosphoric acid. Within specifically identified temperature ranges, the yield of formaldehyde and of methylal can be optimized by controlling the mole fraction or partial pressure of methanol feed.

Abstract: A vascular prosthesis is made by wetting a porous polyester fiber tubing with water until it gains close to maximum amount of weight, removing excess liquid from inside the tubing, repeatedly contacting the inside surface of the tubing with a solution of a biocompatible polymer in a water-immiscible solvent to adsorb some solution on the inside surface of the tubing, and removing excess solution, then removing solvent from the adsorbed solution to form a nonporous elastomer coating of the desired thickness on the inside surface of the tubing.

Abstract: A class of organosilanes of the general formula ##STR1## wherein Ar is a divalent aromatic radical; R.sub.f is a defined fluoroalkyl or perfluoroalkyl ether group; X is methyl, R.sub.f Ar as defined above, a halogen other than fluorine, or an alkoxy group; and each one of Y and Z is a halogen other than fluorine or an alkoxy group. These organosilanes are very useful as precursors to polysiloxane coupling agents for bonding fluoropolymers to glass fibers which can withstand the usual fluoropolymer melt-processing temperatures without decomposition.

Abstract: A nonsegregating dry blend of 90-30 weight percent of elongated polymer pellets having an aspect ratio, A.sub.p, of about 3-23 and a density of about 0.85-1.5 g/cm.sup.3 with 10-70 weight percent of glass fibers having an aspect ratio, A.sub.g, of 3.7-23, the A.sub.p /A.sub.g ratio being about 0.4-1.6, especially 0.8-1.2, can be fed directly to melt-fabricating equipment without first melt-blending the polymer pellets with the glass fibers and fabricated into articles having a substantially uniform glass content.

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: A laminated structure comprising at least two nonadhesive layers and at least one white-pigmented adhesive layer, wherein the white-pigmented adhesive layer is made of a composition stabilized against thermal crosslinking and consequent reduction of its melt index, consisting essentially of a uniform dispersion of alumina-coated titanium dioxide pigment in a blend of a matrix polymer which is a dipolymer of ethylene with an ethylenically unsaturated carboxylic acid or a terpolymer of ethylene with an ethylenically unsaturated carboxylic acid and with another ethylenically unsaturated comonomer, or with carbon dioxide or sulfur dioxide, with a stabilizing polymer which is a high melt index copolymer of ethylene with acrylic or methacrylic acid. Such laminated structures include, for example, toothpaste tubes, condiment pouches, traffic road signs, and roadway lane marking tapes.

Abstract: Surfaces of articles molded from unfilled or lightly filled liquid crystal polymers have a tendency to peel away when subjected to even slight rubbing. Such surfaces are improved by subjecting them to abrasion to remove at least 0.01 mm of surface thickness, whereby they acquire a smooth matte finish and are no longer susceptible to peeling.

Abstract: A copolymer of an unsaturated fluoro compound with a vinyl ether and, optionally, with at least one additional ethylenically unsaturated monomer can be stabilized against gelling by the addition, either to the copolymerization reaction or to the copolymer in solution or in aqueous dispersion, of a 2,2-unsubstituted alicyclic 1,3-diketone in the presence of the enolate ion of said ketone, which enolate may be formed in situ. Solutions and dispersions of such copolymers are very useful in hard, weather-resistant finishes, for example, those used for bridge ironwork and architectural maintenance and in automotive applications.

Abstract: A process for producing an article of a synthetic resin material or a thermoplastic resin blend having a microcellular structure comprises dispersing in a solid thermoplastic resin matrix having hydrophilic functional groups a finely divided water-soluble material, shaping the resin matrix containing the water-soluble material into the desired article, and immersing the shaped article in water at a suitable temperature to cause the resin matrix to swell to an extent of at least about 50% by volume while wet. The immersion causes water to diffuse into the resin matrix and solvate the water-soluble material, which becomes encased in water-filled cells that have solid walls, are substantially closed, and do not form an interconnecting porous network.Articles made by this process include, among others, vascular grafts and organoids.

Abstract: An apparatus and a process for quickly and accurately determining in-line the rheology of molten polymer streams, said apparatus comprising a cam member and a pressure wall member, one of which is a rotating member and the other one is a stationary member, the rotating member dragging molten polymer into a wedge-shaped clearance between the cam member and the pressure wall member, polymer pressure within the clearance being sensed by a pressure detection device capable of producing a signal responsive to said pressure in the form of a display, a graph, or an arbitrary numerical value, but preferably being transmitted to a computer programmed to calculate apparent melt viscosity of the polymer by the application of the Reynold's theory of lubrication.

Abstract: Melt-processible copolymers of at least two halogenated comonomers from a defined class, especially perhalogenated comonomers, and particularly perfluorinated comonomers, of improved thermal stability are obtained by first contacting the copolymers with a stabilizing agent selected from bases (ammonia or amines) having a boiling point at normal pressure of at most 130.degree. C. and tertiary alcohols having up to 8 carbon atoms, to form an intermediate, drying the intermediate at about 70.degree.-150.degree. C., and fluorinating the intermediate at a temperature between 20.degree. C. and the lowest temperature at which the copolymer exhibits a solid state transistion, then removing excess fluorine and by-products and recovering the stabilized copolymer. Such stabilized copolymers are useful for a variety of technically important applications, including as cladding for optical fibers, substrates for electronic components, thermal laminates, pipes, tubes, and fittings, etc.

Abstract: A process for extruding a smooth and uniform film or sheet of an ordered poly(ether ketone ketone) having a thickness of about 2.5 to 250 micrometers, wherein the molten extrudate is quenched on a drum maintained at a temperature of about 100.degree.-170.degree. C.

Abstract: Novel 1,1,2-trifluorodienes, which have a minimum of seven carbon atoms and may contain in their molecule a phenylene or a methylphenylene moiety, are useful monomers, that can be polymerized in the presence of either free radical or coordination catalysts and can undergo selective reactions such, as for example, epoxidation of the vinyl (nonfluorinated) double bond. The resulting perfluorovinyl epoxy compounds also are useful monomers, which can undergo polymerization to useful materials.

Abstract: In a process for the manufacture of shaped polyethylene terephthalate structures, such as film or fiber, a crystalline sodium aluminosilicate molecular sieve is used as the catalyst for the polymerization of di(2-hydroxyethyl phthalate) or higher oligomer intermediate. In film, especially for audio and video tapes, the molecular sieve serves both as the catalyst and as a slip additive. In addition to the fact that this process eliminates antimony trioxide, heretofore used as the polymerization catalyst, the polyethylene terephthalate film made by the process of this invention has considerably fewer defects such as microgel inclusions, black specks, and pimples. Further, the amount of diethylene glycol formed in the process is reduced. Finally, polyethylene terephthalate degradation, contributing to the exudation of lower molecular weight materials, also is reduced.