Abstract: Disclosed are methods for producing rubber-containing bituminous mixtures by pressurizing mixtures of bituminous materials, crumb rubber, and one or more suspension agents with a gas, and then reducing the pressure, creating bubbles of the gas in the mixture. Also disclosed are methods of introducing gas into such mixture by rapid mixing. Mixtures produced by the disclosed methods, such as rubber-containing asphalt mixtures and paving compositions thereof, and their use are also disclosed.

Abstract: Polycarbonate nanocomposites comprising a polycarbonate matrix having non-oxidized metal nanoparticles dispersed therein are disclosed. The polycarbonate nanocomposite is produced by a process comprising forming a reaction mixture comprising a dihydroxy compound, an activated carbonate, a metal precursor, and a solvent; and in-situ polymerizing the reaction mixture to form a nanocomposite comprising a polycarbonate matrix and metal nanoparticles dispersed therein. The metal precursor comprises a metal selected from a specified group. The nanocomposites have improved mechanical, optical, electrical and/or magnetic properties. Also disclosed are articles formed from such polycarbonate nanocomposites.

Abstract: The present invention discloses the use of a supercritical fluid to improve the homogeneity of heterogeneous bi- or multi-modal resins resulting from a physical or a chemical blend of two or more fractions of the same type of polymer resin, said fractions having different molecular weights or of two or more polymer resins having different chemical compositions, or both. It also discloses the use of a supercritical fluid to improve the dispersion of additives or fillers into a polymer resin. It further discloses the process for preparing the homogeneous resin.

Abstract: Method and device for reprocessing a thermoplastic polycondensate, in particular for the recycling of thermoplastic polycondensates, such as polyethylene terephthalate, polyester or polyamide is provided. The polycondensate is introduced into an extruder in a solid state. The polycondensate is then heated to a temperature below melting temperature and degassed or dried at below atmospheric pressure or with an inert gas added. Preferably, to prevent the polycondensate flakes from escaping through a degassing opening, a conveying device is used to convey the escaping flakes back into the extruder. The dried flakes are then melted.

Abstract: The invention relates to a method of preparation for polymers, particularly binders for powder coatings and powder coatings which are prepared as a solution in a supercritical fluid phase. Binders for powder coatings are prepared from at least two ethylenically unsaturated monomers capable of free-radical or ionic copolymerization, and conventional initiators and regulators in supercritical fluids, whereby polymerization is carried out in the homogeneous phase, and, after the reaction has ended, either the composition or the phase parameters of the mixture are altered so that at least two phases with supercritical fluid are obtained, and the phase containing predominantly polymer is separated and the polymer is separated as a powder from the sc fluid by depressurization or the polymer phase is further processed under supercritical phase conditions to the powder coating.

Abstract: A process for rapidly infusing a synthetic resinous substrate with an alkali metal nitrite, comprises (a) essentially completely dissolving the alkali metal nitrite in supercritical carbon dioxide to form a solids-free solution having from about 1 to 15% by weight of the alkali metal nitrite; (b) contacting the synthetic resinous substrate with the solution for a time sufficient to transfer at least a portion of the alkali metal nitrite into the synthetic resinous substrate while maintaining the carbon dioxide under supercritical conditions; and, (c) decreasing pressure or temperature, or both, on the synthetic resinous material sufficiently to evolve carbon dioxide and leave micronized solid alkali metal nitrite crystals in an amount less than 2% by weight essentially uniformly distributed in the synthetic resinous substrate.

Abstract: Continuous process for preparing polyoxymethylene homo- or copolymers by bulk polymerization of the monomers in the presence of cationic initiators, and also, if desired, in the presence of regulators, where during the polymerization both the monomers and the polymer are present in molten form and, if desired, the polymer is then deactivated, and the melt is discharged, cooled and pelletized, which comprises discharging, cooling and pelletizing the polymer at an elevated pressure and in the presence of a liquid.

Abstract: Polymer are removed from organic solvent-polymer mixtures by preparing a liquid-liquid dispersion of finely dispersed solvent droplets containing polymer in water, adding this liquid-liquid dispersion to a stirred vessel containing water or other suitable liquid and rapidly evaporating the solvent to produce a slurry of the polymer in a liquid from which the solid polymer particles are recovered.

Abstract: The present invention involves a method of preparing a reinforced polymer providing improved mechanical properties. The method includes providing particles of the layered silicate and a supercritical fluid. The method further includes mixing the layered silicate with a polymer to form a treatable silicate-polymer mixture and contacting the treatable mixture with the supercritical fluid to exfoliate the silicate particles so that the particles disperse within the polymer. The method further includes depressurizing the contacted mixture to exfoliate the layered silicate so that the layers are substantially dispersed within the polymer to define a reinforced polymer.

Abstract: The present invention is directed to a process and corresponding device for incorporating expanded graphite in a gentle manner into a polyurethane reactive mixture and, on the other hand, processes and corresponding means for reducing or preventing sedimentation of the expanded graphite in the liquid.

Abstract: There has been invented a method for incorporating additives into polymers comprising: (a) forming an aqueous or alcohol-based colloidal system of the polymer; (b) emulsifying the colloidal system with a compressed fluid; and (c) contacting the colloidal polymer with the additive in the presence of the compressed fluid. The colloidal polymer can be contacted with the additive by having the additive in the compressed fluid used for emulsification or by adding the additive to the colloidal system before or after emulsification with the compressed fluid. The invention process can be carried out either as a batch process or as a continuous on-line process.

Abstract: This invention relates to a method of recovering a polymer from an organic mixture comprising polymer and an organic solvent, the method comprising: a) admixing an aqueous solution and the organic mixture by the application of a combined mechanical and hydraulic shear force, the combined mechanical and shear force being sufficient to form a liquid-liquid dispersion; b) removing the organic solvent from the liquid-liquid dispersion thereby forming a remaining solution; and c) separating the polymer from the remaining solution. In one embodiment the polymer is a polycarbonate prepared by the interfacial method, and the organic solvent is methylene chloride.

Abstract: Polyurethane foams formed at elevated pressure using a graft polyol, or mixture of polyols to form a polyol system, having a low functionality and a high solids content, exhibit superior dynamic shock cushioning characteristics (energy absorption) as illustrated by the drop curves of deceleration versus static load. The foam-forming ingredients are mixed together and foamed under controlled pressures in the range of 1.2 to 1.5 bar, preferably 1.3 to 1.4 bar. The polyol preferably has a functionality in the range of about 2.0 to 2.5, a hydroxyl number in the range of about 50 to 90, a solids content above about 35%, preferably about 50 to 55%.

Abstract: The present invention comprises a method for microencapsulating a core material comprising the steps of a) mixing a core material with an encapsulating polymer, b) supplying a supercritical fluid capable of swelling the polymer to the mixture under a temperature and a pressure sufficient to maintain the fluid in a supercritical state, c) allowing the supercritical fluid to penetrate and liquefy the polymer while maintaining temperature and pressure sufficient to maintain the fluid in a supercritical state, and d) rapidly releasing the pressure to solidify the polymer around the core material to form a microcapsule. This method requires neither that the polymer nor core materials to be soluble in the supercritical fluid and can be used to rapidly and efficiently microencapsulate a variety of materials for a variety of applications.

Abstract: Disclosed is a method for impregnating a thermoplastic polymer with an impregnation material such as a fragrance or pest control agent or pharmaceutical composition. A thermoplastic polymer is impregnated by (1) dissolving an impregnation material such as a fragrance or pest control agent or pharmaceutical composition material in a volatile swelling agent maintained at or near supercritical conditions for the volatile swelling agent, (2) swelling the thermoplastic polymer by contacting it at or near supercritical conditions for the volatile swelling agent with the impregnation material-laden volatile swelling agent and then (3) reducing the pressure so that the volatile swelling agent diffuses out of the thus impregnated thermoplastic polymer.

Abstract: A process for producing cast unsaturated thermosetting resins which are highly stain resistant is disclosed. A pressurization step is applied to the thermosetting resin prior to casting to reincorporate any volatilized monomer which has volatilized during a previous deaeration step. The resultant casting is non-porous in cross-section which produces a product which is both stain resistant and machinable in the field without exposing voids.

Abstract: Disclosed is a method for impregnating a thermoplastic polymer with an impregnation material such as a fragrance or pest control agent or pharmaceutical composition. A thermoplastic polymer is impregnated by (1) dissolving an impregnation material such as a fragrance or pest control agent or pharmaceutical composition material in a volatile swelling agent maintained at or near supercritical conditions for the volatile swelling agent, (2) swelling the thermoplastic polymer by contacting it at or near supercritical conditions for the volatile swelling agent with the impregnation material-laden volatile swelling agent and then (3) reducing the pressure so that the volatile swelling agent diffuses out of the thus impregnated thermoplastic polymer.

Abstract: A method for processing a polymer solution by changing the thermodynamic state of the solution to produce a dilute phase and a concentrated phase such that the thermodynamic state is sufficiently changed that the two phases are formed by spinodal decomposition.

Abstract: This invention relates to a vinyl acetate-ethylene copolymer containing emulsion particularly adapted for the preparation of nonwoven goods. The vinyl acetate-ethylene emulsion is prepared by an improved process for producing an aqueous emulsion suitably adapted for producing non-woven goods said emulsion containing a vinyl acetate-ethylene copolymer wherein said copolymer contains from about 75-96% by weight of vinyl acetate. It is produced by forming an aqueous suspension of vinyl acetate, ethylene, and stabilizer, initiating the polymerization of the reaction mixture by the addition of catalysts, and adding from about 0.5-10% by weight of the vinyl acetate of a crosslinkable monomer. The improvement for enhancing the absorptivity of the copolymer comprises:pressurizing the reactor with ethylene to an initial ethylene equilibrium pressure of from about 100 to 1,000 psig;initiating the reaction mixture by the addition of catalyst at a temperature from about 10.degree.-35.degree. C.