Abstract: High quality plastic foam and the like expanded products and articles are made by incorporating a blowing agent in an acid-containing alkenyl aromatic polymer, such as a copolymer of styrene and acrylic acid; extruding while cross-linking the polymer with a polyfunctional cross-linking agent.

Abstract: Excellently properties, thermoplastic compositions well adapted for conversion by conventional melt-processing extrusion and other ordinary fabrication techniques into very good quality, lightly cross-linked, thermocollapse-resistant, closed-cell plastic foam(s) and the like expanded cellular product(s) are comprised of an intimate mixture of:(A) a sparsely hydroxylated, normally-solid olefin polymer, particularly a linear alkenyl aromatic or polyolefin polymer which is frequently at least substantially a styrene polymer which is generally in copolymeric form with appropriate moieties of comonomers adapted to provide the requisite attached hydroxyl units therein and thereon; and(B) a minor proportion of an inter-reactive, cross-linking polyisocyanate constituent.

Abstract: Mechanically stable styrene polymer foams having highly desirable physical properties are prepared employing as a blowing agent a mixture of lower alcohols with chlorofluoromethanes.

Abstract: Plastic particles having diameters of from about 1 to about 150 microns, a polymeric bonding layer on the surface thereof, are coated with magnetic particles to provide a generally uniform coating having a thickness of from about 0.05 to about 0.8 of a micron.

Abstract: Block copolymers are prepared having end blocks with random copolymer of styrene and/or alkyl substituted derivatives and alpha-methylstyrene ranges from 1:0.5 to 1:2.5, a central block of a polydiene polymer joins the terminal blocks. The block copolymers contain from 10 to 90 weight percent of polydiene, the remaining portion being of random (alkyl) styrene-alpha-methylstyrene copolymer. The polymers range from medium impact polystyrene type polymer of low polydiene content to thermoplastic elastomers of high polydiene content.

Abstract: Tetrafluoroethylene polymer tubes suitable for the preparation of lined pipe are prepared by ram extrusion wherein the tube is extruded above the sinter temperature and cooled below its crystalline melting point while radially unsupported to provide a tube of improved dimensional stability under thermal cycling.

Abstract: Tetrafluoroethylene polymer tubes are ram extruded. Desirable quality tubes are obtained by positioning an insert between ram and mandrel to maintain the ram and mandrel concentric.

Abstract: Diene-styrene-.alpha.-methylstyrene block polymers are prepared by polymerization in excess .alpha.-methylstyrene with a lithium initiator wherein styrene-.alpha.-methylstyrene block is polymerized at a temperature from about 20.degree. centigrade to about 160.degree. centigrade with the ratio of styrene to .alpha.-methylstyrene being from about 50 to 1 to about 1 to 50.

Abstract: A heat exchange assembly is provided which employs concentric flat plate heaters, the heat exchange assembly having a common fixed tube sheet and floating tube sheet; the floating tube sheet comprising two concentric portions having frustoconical interface thereby, the frustoconical interface when projected has its apex in a plane containing the adjacent face of the fixed tube sheet in the axis of generation of the flat plate heater. Thermal stress on the floating tube sheet is thereby relieved. The heat exchanger is useful as a reactor particularly where the temperature profile of the material flowing therethrough is controlled or varied.

Abstract: A heat exchange assembly is provided which employs concentric flat plate heaters. The heat exchanger is useful as a reactor particularly where the temperature profile of the material flowing therethrough is controlled or varied.

Abstract: Mechanically stable styrene polymer foams having highly desirable physical properties are prepared employing as a blowing agent a mixture of lower alcohols with chlorofluoromethanes.

Abstract: Profiled heat seals in plastic film are provided by opposed profiled heat sealing platens supported on endless chains. The platens are heated by contact with associated heating drums.

Abstract: Magnetic imbiber polymers are prepared by grafting a water soluble polymer on the surface of an oil imbiber polymer and exposing the grafting imbiber polymer to a colloidal magnetic material such as magnetic iron oxide.

Abstract: Styrene is polymerized employing a free radical initiator in the presence of a styrene-diene block copolymer of the AB or AB (BA).sub.n configuration to provide a polymer containing from about 15 to 30 weight percent diene units polymerized therein. The polymer contains polydiene domains in the form of rods and spheres having diameters of 50 nanometers or less.

Abstract: Ammonium nitrate activated or catalyzed with certain chromium compounds provides an excellent, low cost blowing or expanding agent(s) for many foamable polymers, including polyethylene(s), polystyrene(s), etc.

Abstract: Gas transmission rates for and taken across plastic specimens are accurately measured in suitable apparatus for the purpose by a dynamic technique involving constant measurement of pertinent temperature and pressure data which is permitted to constantly change throughout the measurement testing.

Abstract: A polystyrene is prepared from a C.sub.8 cracker stream by first hydrogenating phenylacetylene to styrene and subsequently anionically polymerizing the styrene.

Abstract: In the mass polymerization of an alkenyl aromatic nitrile rubber polymer blend such as ABS by the mass polymerization technique, improved physical properties are obtained in the resultant polymer by the incorporation of water into the mass polymerization process. During polymerization the pressure of the system must be maintained sufficiently high to prevent vaporization of the water.

Abstract: A system for non-destructive, non-contacting use for detecting imperfections in multi-layered supply rolls of wound plastic film comprises a laser which scans the length of the particular roll being inspected with a photo-electric detector at a fixed reference angle which picks up reflected unimpeded and scattered light plus associated indicating and/or recording equipment. Defects in the roll, particularly those related to the upper longitudinal surface thereof, cause light scattering which decreases the signal strength to the indicator or recorder, thus noting the presence of a wrinkle or the like imperfection in the film roll.

Abstract: Reduced breakage and reduced internal gas pressure is achieved in the trapped bubble process for the preparation of film by applying vacuum to the region of the tube where the bubble starts to form.