Abstract: This invention relates to a process of preparation of components and articles of manufacture containing at least one of such components, such as tires, and the resulting prepared components and fabricated articles, by use of directed high frequency energy internally heated silica-rich rubber compositions which contain sulfur curative and a significant content of high softening point polymer, namely a polymer and/or elastomer having a melting point (Tm) and/or high glass transition temperature (Tg) above 0° C., and particularly above 30° C., and which contains a minimal, if any, carbon black reinforcement. Such directed high frequency energy heating is provided, individually, by directed radio frequency (electromagnetic) radiation and/or by directed microwave radiation.

Abstract: The invention provides a sterile medical implant or medical implant part comprising ultrahigh molecular weight polyethylene that has a molecular weight of about 400,000 atomic mass units or more. The invention also provides methods for producing, using, and preparing a medical implant or medical implant part, which comprise contacting the medical implant or medical implant part with water, such that the weight of the ultrahigh molecular weight polyethylene is increased, and the wear performance of the medical implant or medical implant part desirably is enhanced.

Abstract: A method is provided for forming a plastic prosthesis bearing, net-shape bearing, near net-shape bearing or plastic stock from which such a bearing can be formed. The method includes the steps of providing plastic resin in powdered form, subjecting the powdered resin to irradiation to cross-link the resin, and molding the irradiated powder. The irradiated powder is molded by applying heat and pressure to form the powder into a desired solid plastic shape, the heating being sufficient to melt the powder.

Abstract: A medical implant of ultrahigh molecular weight polyethylene having an improved balance of wear properties and oxidation resistance is prepared by irradiating a preform of ultrahigh molecular weight polyethylene, annealing the irradiated preform in the absence of oxygen to a temperature at or above the onset of melting temperature, and forming an implant from the stabilized cross-linked polymer. Implants prepared according to the process of the present invention have comparable oxidation resistance and superior wear performance compared to unirradiated ultrahigh molecular weight polyethylene.

Abstract: A source of radiation (10,12), particularly a pulsed accelerated electron beam, directs a beam of radiation through an irradiation chamber (14, 50). The irradiation chamber is depleted of oxygen and oxygen containing gases, such as being drawn to a vacuum of 10−1 or greater Torr by a vacuum pump (20, 52). Particulate fluoropolymer material is entrained (36) in substantially oxygen free gas and conveyed through the irradiation chamber. The accelerated electrons break chemical bonds in the fluoropolymer particles and electrostatically charge the particles. Magnetic fields (42, 60) of different polarity rotate the charged particles such that they are irradiated from different sides. The irradiated fluoropolymer particles are cooled (24) and separated (26) from the entraining gas. The entraining gas is recirculated through pneumatic line (34) for a continuous cycle. In an alternate batch processing embodiment, the fluoropolymer material is placed in the shallow container (50) which is sealed and evacuated.

Abstract: A medical implant of ultrahigh molecular weight polyethylene having an improved balance of wear properties and oxidation resistance is prepared by irradiating a preform of ultrahigh molecular weight polyethylene, annealing the irradiated preform in the absence of oxygen to a temperature at or above the onset of melting temperature, and forming an implant from the stabilized cross-linked polymer. Implants prepared according to the process of the present invention have comparable oxidation resistance and superior wear performance compared to unirradiated ultrahigh molecular weight polyethylene.

Abstract: A medical implant of ultrahigh molecular weight polyethylene having an improved balance of wear properties and oxidation resistance is prepared by irradiating a preform of ultrahigh molecular weight polyethylene, annealing the irradiated preform in the absence of oxygen to a temperature at or above the onset of melting temperature, and forming an implant from the stabilized cross-linked polymer. Implants prepared according to the process of the present invention have comparable oxidation resistance and superior wear performance compared to unirradiated ultrahigh molecular weight polyethylene.

Abstract: Wear resistance and oxidation resistance of polymer material or a polymer component for bioimplantation are improved by packaging a polymer object in a sealed gas impermeable package substantially free of oxygen, irradiating the package with penetrating radiation to an extent sufficient to effect a desired substantial level of cross-linking within the polymer, and warming the packaged object while maintaining an elevated hydrostatic pressure to cause gases released during irradiation to recombine, stabilizing the material against subsequent oxidative change. The pressure stabilization terminates active sites, substantially eliminating free radicals. When applied to finished parts, the process simultaneously hardens and sterilizes the parts without degrading mechanical properties or dimensions. When applied to bulk material or unfinished parts, the part may be subsequent machined or otherwise finished, and sterilized by any conventional means.

Abstract: A medical implant of ultrahigh molecular weight polyethylene having an improved balance of wear properties and oxidation resistance is prepared by irradiating a preform of ultrahigh molecular weight polyethylene, annealing the irradiated preform in the absence of oxygen to a temperature at or above the onset of melting temperature, and forming an implant from the stabilized cross-linked polymer. Implants prepared according to the process of the present invention have comparable oxidation resistance and superior wear performance compared to unirradiated ultrahigh molecular weight polyethylene.

Abstract: Polypropylene mixtures of increased stress-crack resistance and melt strength can be produced by irradiating polypropylene powders with low average particle diameters by low energy electron-beam accelerators with energies of 150 to 300 keV. The polypropylene mixtures produced are suitable particularly for producing films, sheets, panels, coatings, pipes, hollow objects and foamed materials.

Abstract: Disclosed is a normally solid, high molecular weight, non-linear, substantially gel-free, propylene polymer material characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, foaming and thermoforming.

Abstract: Disclosed is a normally solid, high molecular weight, non-linear, substantially gel-free, propylene polymer material characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, foaming and thermoforming.

Abstract: Deep section epoxy compositions are cured by irradiation with e-beam, x-ray,or .gamma.-ray radiation. Use of photoinitiators having metal halide anions makes monomers and oligomers especially susceptible of this invention's deep section curing technology.

Abstract: A method for forming an agarose electrophoretic gel by addition of gamma-irradiated clarified galactomannan (.gamma.CGM) to optically clarify the gel and improve the electrophoretic fractionation and resolution of oligonucleotides differing in molecular weight. The gel includes agarose, an electrophoretic buffer for nucleic acids, and a CGM vegetable gum subjected to between 0.1 and 4.0 megarads of ionizing gamma radiation.

Abstract: A process for producing a slow-release powder which permit various active ingredients such as perfumes, insect control agents, rust inhibitors, mold inhibitors and antibacterial agents to be slowly released over a prolonged time, the process comprising the steps of mixing a long-chain compound with the ingredients, mixing the resulting mixture with urea, and exposing the resulting urea adduct to radiation.

Abstract: A transparent polyurethane layer which is resistant to fogging. The layer contains monomers and/or oligomers of acrylic acid or of salts of said acid grafted radiochemically to the surface of said layer. The layer is used as a coating layer for laminated glazings.

Abstract: This invention is directed to a thermal or radiation curable prepolymer, formulations containing same and processes of using same, said prepolymer comprising a liquid meth(acrylate) terminated polymeric hydrocarbon maleate having pendant maleate groups. Said prepolymer either per se or formulated with mono- or multi-functional unsaturated monomers and either a thermal or photoinitiator on exposure to heat or UV or high energy ionizing radiation forms a cured material utilizable as a printing plate, coating, adhesive or sealant.

Abstract: Water-soluble polymers comprising an N-vinyl lactam are found to be useful in processes wherein the polymer is introduced into a subterranean wellbore.Polymers useful in the recovery of natural resources are prepared by polymerizing an N-vinyl lactam by free radical initiation, with polymerization conducted in an aqueous solution polymerization medium preferably containing a mixture of dissolved electrolytes, or in a polymerization medium consisting essentially of a tertiary alkanol. Copolymers of such N-vinyl lactams with unsaturated amides, and terpolymers prepared by polymerizing an N-vinyl lactam and an unsaturated amide with a selected termonomer compound are also useful when prepared by these methods.