Abstract: The present invention relates to methods for making cross-linked oxidation-resistant polymeric materials and preventing or minimizing in vivo elution of antioxidant from the antioxidant-containing polymeric materials. The invention also provides methods of doping polymeric materials with a spatial control of cross-linking and antioxidant distribution, for example, vitamin E (?-Tocopherol), and methods for extraction/elution of antioxidants, for example, vitamin E (?-tocopherol), from surface regions of antioxidant-containing polymeric materials, and materials used therewith also are provided.

Abstract: A method for obtaining a composition of at least two components, comprising the steps of: providing at least one first fluid component; providing at least one second solid component and processing it so that the first component can diffuse into the second component; and diffusing the first component into the second component. A composition prepared by such a method.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: Crosslinked polyolefin blends, methods for their production, and articles made of the same are provided. In at least one specific embodiment, the polyolefin blends comprise a first polymer formed in a first reactor and a second polymer formed in a second reactor. The first and second polymers, as well as the resulting blend, may comprise units derived from propylene, ethylene, and a diene. The blended composition can then be compounded with one or more coagents, antioxidants, and/or other additives and crosslinked, preferably by exposure to energetic photons. The crosslinked polymers are particularly useful for making fibers, films, and nonwovens.

Abstract: Crosslinked ultra-high molecular weight polyethylene (UHMW-PE) is disclosed, as well as molded bodies made from the UHMW-PE and a process for making such UHMWE-PE.

Abstract: Disclosed herein is a polymeric composition comprising a polymeric composition comprising a first crosslinked network; and a second crosslinked network; wherein the first crosslinked network is crosslinked at a first stress and/or a first strain and the second crosslinked network is crosslinked at a second stress and/or a second strain; where the first stress and/or the first strain is different from the second stress and/or the second strain either in magnitude or direction. Disclosed herein is a method comprising subjecting a polymeric mass to a first stress and/or a first strain level; crosslinking the polymeric mass to form a first crosslinked network; subjecting the polymeric mass to a second stress and/or a second strain level; and crosslinking the polymeric mass to form a second crosslinked network; where the first stress and/or the first strain level is different from the second stress and/or the second strain level.

Abstract: A process produces a block of polyolefin material with uniform crosslinking, which may be uniform between and within polymer chains in the polyolefin material. Steps include: providing an oven; placing the block into the oven; preheating the block to a uniform temperature above the melting point; further heating the block to a temperature at least 30 degrees Centigrade above the melting point; cooling the block to room temperature under an inert gas; and removing oxidized material from surface of the block. Optional steps include: subjecting the block to radiation before placing the block into the oven; removing the gases from the oven on a continuous or stepwise basis; controlling the purge gas flow out of the oven; and determining a heating time period for the block by subjecting control blocks to the same process and analyzing them after various heating times.

Abstract: Farnesene interpolymer comprises units derived from a farnesene (e.g., ?-farnesene or ?-farnesene) and units derived from at least one vinyl monomer. The farnesene interpolymer can be prepared by copolymerizing the farnesene and at least one vinyl monomer in the presence of a catalyst. In some embodiments, the farnesene is prepared from a sugar by using a microorganism. In other embodiments, the at least one vinyl monomer is ethylene, an ?-olefin, or a substituted or unsubstituted vinyl halide, vinyl ether, acrylonitrile, acrylic ester, methacrylic ester, acrylamide or methacrylamide, or a combination thereof.

Abstract: An insulating film formed by a method comprising: coating a film-forming composition containing a compound having a cage structure; and drying the coated composition, wherein the coated composition is irradiated with a light having a wavelength of 200 nm or less in at least one of during the drying and after the drying; a process for producing the same; and an electronic device having the same.

Abstract: The invention is directed to a use of a polymer composition comprising an ethylene polymer for producing a crosslinked pipe, a process for producing a crosslinked pipe and to a crosslinked pipe comprising a crosslinked polymer composition which comprises a crosslinked ethylene polymer.

Abstract: The invention is directed to a use of a polymer composition comprising an ethylene polymer for producing a crosslinked article, a process for producing a crosslinked article and to a crosslinked article comprising a crosslinked polymer composition which comprises a crosslinked ethylene polymer.

Abstract: Methods of forming polymeric articles using plasma treated polymer resins, and orthopedic implants comprising a polymeric article wherein the polymeric article has reactive groups bonded to polymer molecules in an interior region of the polymeric article.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: A radiation crosslinked (50 kGy), pressure-treated UHMWPE material has been developed by applying compressive force on a crosslinked polymer in a direction orthogonal to an axial direction. The deformed material is then cooled while held in a deformed state. The resulting material is anisotropic, with enhanced strength oriented along the axial direction. The directionally engineered material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPEs.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: Oxidation resistant crosslinked ultrahigh molecular weight polyethylene (UHMWPE) is described, wherein at least two different additives in the manufacture synergistically increase the oxidation resistance of crosslinked UHMWPE. This allows the manufacture of oxidation resistant crosslinked UHMWPE using lower levels of additives and/or lower levels of crosslinking irradiation or chemicals. The lower levels of additives and/or crosslinking produce crosslinked UHMWPE having desired physical properties not possible without the synergistic interaction of the additives. This crosslinked UHMWPE may be used in medical prostheses such as in bearing components having desired physical properties such as wear resistance and oxidation resistance not possible without the synergistic interaction of the additives.

Abstract: The present invention relates to methods for making wear and oxidation resistant polymeric materials by high temperature melting. The invention also provides methods of making medical implants containing cross-linked antioxidant-containing tough and ductile polymers and materials used therewith also are provided.

Abstract: A process for preparing a pressure sensitive adhesive using a modified planetary roller extruder is described. The process in accordance with one aspect of the invention includes introducing primary raw materials including a non-thermoplastic elastomer into a feeding section of the modified planetary roller extruder, conveying the raw materials from the feeding section to a compounding section of the modified planetary roller extruder, continuously mixing the primary raw materials in the compounding section to produce a homogeneous adhesive composition. The adhesive composition may be applied to a web-form material. The compounding section of the modified planetary roller extruder includes a main spindle surrounded by and intermeshed with a plurality of planetary spindles at least one of which is a double transversal mixing spindle having a plurality of back-cut helical flights.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: Certain embodiments described herein are directed to polymer compositions including a protected antioxidant. In some examples, the compositions can also include a deprotected antioxidant, an unprotected antioxidant or both. Methods of producing compositions including a protected antioxidant and articles including a protected antioxidant are also described.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.

Abstract: A method of producing an improved polyethylene, especially an ultra-high molecular weight polyethylene utilizes a sequential irradiation and annealing process to form a highly cross-linked polyethylene material. The use of sequential irradiation followed by sequential annealing after each irradiation allows each dose of irradiation in the series of doses to be relatively low while achieving a total dose which is sufficiently high to cross-link the material. The process may either be applied to a preformed material such as a rod or bar or sheet made from polyethylene resin or may be applied to a finished polyethylene part. If applied to a finished polyethylene part, the irradiation and annealing must be accomplished with the polyethylene material not in contact with oxygen at a concentration greater than 1% oxygen volume by volume.

Abstract: The present invention discloses methods for enhancing the wear-resistance of polymers, the resulting polymers, and in vivo implants made from such polymers. One aspect of this invention presents a method whereby a polymer is irradiated, preferably with gamma radiation, then thermally treated, such as by remelting of annealing. The resulting polymeric composition preferably has its most oxidized surface layer removed. Another aspect of the invention presents a general method for optimizing the wear resistance and desirable physical and/or chemical properties of a polymer by crosslinking and thermally treating it. The resulting polymeric compositions is wear-resistant and may be fabricated into an in vivo implant.

Abstract: The present invention discloses methods for enhancing the wear-resistance of polymers, the resulting polymers, and in vivo implants made from such polymers. One aspect of this invention presents a method whereby a polymer is irradiated, preferably with gamma radiation, then thermally treated, such as by remelting of annealing. The resulting polymeric composition preferably has its most oxidized surface layer removed. Another aspect of the invention presents a general method for optimizing the wear resistance and desirable physical and/or chemical properties of a polymer by crosslinking and thermally treating it. The resulting polymeric compositions is wear-resistant and may be fabricated into an in vivo implant.

Abstract: Solid-state deformation processing of crosslinked high molecular weight polymers such as UHMWPE, for example by extrusion below the melt transition, produces materials with a combination of high tensile strength and high oxidative stability. The materials are especially suitable for use as bearing components in artificial hip and other implants. Treated bulk materials are anisotropic, with enhanced strength oriented along the axial direction. The material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted crosslinked UHMWPE.

Abstract: An antioxidant combined with UHMWPE prior to subjecting the UHMWPE to crosslinking irradiation. In one exemplary embodiment, the antioxidant is tocopherol. After the antioxidant is combined with the UHMWPE, the resulting blend may be formed into slabs, bar stock, and/or incorporated into a substrate, such as a metal, for example. The resulting product may then be subjected to crosslinking irradiation. In one exemplary embodiment, the UHMWPE blend is preheated prior to subjecting the same to crosslinking irradiation. Once irradiated, the UHMWPE blended product may be machined, packaged, and sterilized in accordance with conventional techniques.

Abstract: A method of forming carbon nanotube-polymer composites includes the steps of forming a mixture solution including a plurality of carbon nanotubes dispersed in a co-solvent. The co-solvent includes an organic solvent and a second solvent being a short chain fluorinated carboxylic acid having a boiling point below 150° C. which is less oxidizing than nitric acid, and is soluble in both the organic solvent and water. The first polymer is mixed with the mixture solution to form a polymer including mixture. The co-solvent is removed from the polymer mixture to form a dispersed nanotube-polymer composite. The second solvent can be trifluoroacetic acid.

Abstract: Solid-state deformation processing of crosslinked high molecular weight polymers such as UHMWPE, for example by extrusion below the melt transition, produces materials with a combination of high tensile strength and high oxidative stability. The materials are especially suitable for use as bearing components in artificial hip and other implants. Treated bulk materials are anisotropic, with enhanced strength oriented along the axial direction. The material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted crosslinked UHMWPE.

Abstract: A technique for imparting latent elasticity to components of an absorbent article is provided. More specifically, a latent elastic film that contains a crosslinkable semi-crystalline polyolefin is initially incorporated into an absorbent article. The film is not highly elastic prior to crosslinking and is thus dimensionally stable. Consequently, the film need not be maintained in a mechanically stretched condition during attachment to other components of the absorbent article, which provides for greater freedom in the location and manner in which the components are attached together. Once incorporated into the absorbent article, the semi-crystalline polyolefin is crosslinked to form a three-dimensional network having elastic memory. The film may also be heat activated, either through crosslinking or an additional step, to cause the film to shrink and further improve its stretch characteristics.

Abstract: A polyethylene composition is provided that has a density of about 0.945 to about 0.960 g/cm3 and a melt flow index of about 0.1 to about 0.4. The composition is a melt blend of a linear low density polyethylene resin and/or a linear medium low density polyethylene resin, and a high density polyethylene resin. A feature of the composition is that the resins can independently be virgin, recycled, scrap and/or wide specification resins, and mixtures of these. Methods of producing the compositions and extruded, molded and formed plastic articles manufactured from the compositions are presented.

Abstract: The present invention generally provides implantable articles and methods of forming implantable articles from a crosslinked ultrahigh molecular weight polyethylene (“UHMWPE”) blend stabilized with Vitamin E. The crosslinked UHMWPE blend may be prepared by combining the UHMWPE material and vitamin E prior to irradiating the UHMWPE blend with electron beam radiation at a sufficient radiation dose rate to induce crosslinking.

Abstract: A medical prosthesis for use within the body which is formed of radiation treated ultra high molecular weight polyethylene having substantially no detectable free radicals, is described. Preferred prostheses exhibit reduced production of particles from the prosthesis during wear of the prosthesis, and are substantially oxidation resistant. Methods of manufacture of such devices and material used therein are also provided.

Abstract: The present invention relates to a process for chemically modifying, within its thickness, a polymer matrix chosen from matrices made of fluoropolymers and matrices made of aliphatic polymers, said process comprising at least one step consisting in irradiating said matrix with UV light having a wavelength of less than 300 nm in order to generate, within the thickness of said matrix, zones that have short polymer chains, formed by scission of the existing chains during the passage of the UV radiation and that have free radicals denoted hereinbelow as “activated zones”. The present invention also relates to the polymer matrix capable of being chemically modified by such a process.

Abstract: The present invention generally provides implantable articles and methods of forming implantable articles from a crosslinked ultrahigh molecular weight polyethylene (“UHMWPE”) blend stabilized with Vitamin E. The crosslinked UHMWPE blend may be prepared by combining the UHMWPE material and vitamin E prior to irradiating the UHMWPE blend with electron beam radiation at a sufficient radiation dose rate to induce crosslinking. The crosslinked UHMWPE blend may be incorporated into a variety of implants, and in particular, into endoprosthetic joint replacements.

Abstract: The present invention provides partial and complete shielding approaches to alter the cross-linking characteristics of irradiated polymers, such as polyethylene. Irradiated polymers and fabricated articles, such as medical prosteses, comprising irradiated polymers also are provided.

Abstract: A radiation crosslinked (50 kGy), pressure-treated UHMWPE material has been developed by applying compressive force on a crosslinked polymer in a direction orthogonal to an axial direction. The deformed material is then cooled while held in a deformed state. The resulting material is anisotropic, with enhanced strength oriented along the axial direction. The directionally engineered material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPEs.

Abstract: Polymer/carbon nanotube composites including single-wall or multi-wall carbon nanotubes incorporated into the matrix of a polymer are provided. These composites can be used in environments exposed to galactic cosmic radiation. Accordingly, the composites are useful in deep space applications like space vehicles, space stations, personal equipment as well as applications in the biomedical arts and atom splitting research. The composites can be modified with organic dyes containing at least one phenyl ring and the resulting doped composite is useful as a radiation detector. The preferred polymer is poly(4-methyl-1-pentene). At low nanotube concentrations (i.e., about 0.5 wt % or less), the composites exhibit transparent optical qualities. At higher nanotube concentrations (i.e., about 0.6 wt % or more), the composites are non-transparent.

Abstract: the invention provides a composition having laser engraving properties, comprising a host material and a laser enhancing additive. The host material comprises a material, such as a polymer, modified by a first process, whereby the host material as modified by the first process has increased thermal conductivity as compared to the host material before the first process. The laser enhancing additive comprises a first quantity of at least one of copper potassium iodide (CuKI3), Copper Iodide (CuI), potassium iodide (KI), sodium iodide (NaI), and aluminum iodide (AlI), and a second quantity of at least one substance selected from the group consisting of zinc sulfide (ZnS), barium sulfide (BaS), alkyl sulfonate, and thioester.

Abstract: A method of producing an improved polyethylene, especially an ultra-high molecular weight polyethylene utilizes a sequential irradiation and annealing process to form a highly cross-linked polyethylene material. The use of sequential irradiation followed by sequential annealing after each irradiation allows each dose of irradiation in the series of doses to be relatively low while achieving a total dose which is sufficiently high to cross-link the material. The process may either be applied to a preformed material such as a rod or bar or sheet made from polyethylene resin or may be applied to a finished polyethylene part. If applied to a finished polyethylene part, the irradiation and annealing must be accomplished with the polyethylene material not in contact with oxygen at a concentration greater than 1% oxygen volume by volume.

Abstract: There is provided a method for preparing a plumbing manifold for use in a water system in which the manifold after molding is subjected to cross-linking high energy radiation. The manifold is made by polyethylene or a metallocene polyethylene.

Abstract: Polyolefin waxes bearing (meth)acrylate groups, process for preparing them and their use.

Abstract: The present subject matter relates generally to polymer compositions, and more particularly to irradiated polymer compositions comprising at least one non-phenolic stabilizer. The present polymer compositions comprise an unexpected balance of properties after being subjected to irradiation treatments, including an unexpected combination of a lower melt flow rate ratio (MFRr) and high melt tension after being irradiated, while minimizing negative yellowing effects.

Abstract: UHMWPE is exposed to crosslinking radiation and than heated utilizing infrared radiation. In one exemplary embodiment, the infrared radiation is provided by an infrared heater having a tungsten heating element with a quartz tube. In this embodiment, the infrared radiation may have the wavelength from about 1.0 micron to about 1.5 microns. In another exemplary embodiment, the UHMWPE is compression molded into bars prior to exposure to the crosslinking radiation.

Abstract: UHMWPE is exposed to crosslinking radiation and than heated utilizing infrared radiation in an inert environment. In one exemplary embodiment, the infrared radiation is provided by an infrared heater having a tungsten heating element with a quartz tube. In this embodiment, the infrared radiation may have the wavelength from about 1.0 micron to about 1.5 microns. In another exemplary embodiment, the UHMWPE is compression molded into bars prior to exposure to the crosslinking radiation.

Abstract: Highly crystalline, oxidation resistant crosslinked polymeric materials such as crosslinked ultrahigh molecular weight polyethylenes having high wear resistance, enhanced stiffness, enhanced tensile strength, a high level of fatigue and crack propagation resistance, and enhanced creep resistance can be manufactured by the new methods described herein.

Abstract: The present invention provides novel hybrid polymer useful for alignment layers for inducing alignment of a liquid crystal medium. Hybrid polymers of this invention are prepared from at least one component selected from the group consisting of monomer, oligomer and polymer within the class of polyimides, poly(amic acids) and esters thereof and at least one component selected from the group consisting of addition monomer and functionalized addition polymer wherein the two components are covalently bonded to form a copolymer. The invention further describes liquid crystal optical elements such as all liquid crystal display products or modes, liquid crystal devices and liquid crystal optical films comprising the novel hybrid polymer alignment layers.

Abstract: The present invention provides a bearing material that is excellent in durability and is capable of maintaining wear resistance over a long period of time. The bearing material of the present invention is a high wear-resistance bearing material 10 for being used under a humid environment comprising: a base body 12 made of a polymer material having a methylene group; and a polymer layer 30 covering a bearing surface 16 of the substrate 12, the polymer layer 30 comprising polymer chains which have a phosphorylcholine group and are grafted from the bearing surface 16, wherein a phosphoric index of the sliding surface 16 which is calculated by dividing a peak intensity of phosphate group in an infrared spectrum measured on the sliding surface by a peak intensity of the methylene group therein is not less than 0.28.

Abstract: The present invention relates to a novel process for the preparation of solid-supported scavenging reagents and solid-supported functional polymers. The invention further relates to novel solid-supported functional polymers and to their use in organic synthesis and combinatorial chemistry.

Abstract: An article suitable for use as an insulating or coating material comprises a radiation-crosslinked composition comprising a polyethylene, a polypropylene and optionally an ethylene-propylene elastomer. The polyethylene component is selected from high density polyethylene (HDPE), medium density polyethylene (MDPE) and linear medium density polyethylene (LMDPE) and the polypropylene component is either a homopolymer or copolymer. The composition is predominantly based on the polyethylene component and contains the polyethylene component in an amount of at least 50 percent by weight. The article is radiation-crosslinked to a sufficient degree that it possesses thermoset properties, such that when the article is heated to a temperature above the crystalline melting point of the polypropylene homopolymer or copolymer, it is softened but does not become liquid.

Abstract: The present invention provides an irradiated crosslinked polyethylene containing reduced free radicals, preferably containing substantially no residual free radical. Disclosed is a process of making irradiated crosslinked polyethylene by irradiating the polyethylene in contact with a sensitizing environment at an elevated temperature that is below the melting point, in order to reduce the concentration of residual free radicals to an undetectable level. A process of making irradiated crosslinked polyethylene composition having reduced free radical content, preferably containing substantially no residual free radicals, by mechanically deforming the polyethylene at a temperature that is below the melting point of the polyethylene, optionally in a sensitizing environment, is also disclosed herein.