Abstract:
A method for modifying the plastic surface of an article adapted for contacting living tissue by the gamma or electron beam irradiation induced chemical graft coating thereon of:(1) a neutral or ionic water-soluble, hydrophilic vinylic monomer or salt thereof;(2) a mixture of at least two of said monomers, or(3) a mixture of (1) or (2) with up to about 50%, by weight, based on the total monomer weight, of a member selected from the group consisting of N-vinylpyrrolidone, 2-hydroxyethyl-methacrylate, and mixtures thereof; so as to form a hydrophilic graft polymer coating on the surface.
Abstract:
A process for producing a reactive aqueous emulsion comprising dispersing a monomer mixture of (a) 65.0 - 98.8% by weight of radical polymerizable hydrophobic ethylenic unsaturated monomer having one ethylenic unsaturated bond, (b) 1.0 - 30.0% by weight of radical polymerizable ethylenic unsaturated monomer having a glycidyl group and (c) 0.2 - 5.0% by weight of a radical polymerizable ethylenic unsaturated monomer having a carboxylic group in water by virtue of a restricted amount of surface active agent and irradiating with an ionizing radiation for a total dose of more than 0.01 Mrad at temperatures ranging from -5.degree. C. to 50.degree. C. This reactive aqueous emulsion does not contain low-molecular water-soluble compounds such as a radical polymerization initiator, a pH regulator, etc. and can form a film having improved properties.
Abstract:
This invention provides a process for producing a transparent shaped polymeric product which is free from defects such as strain and bubbles and has improved chemical and physical properties. The product is produced from a methyl methacrylate- or methyl acrylate-based monomer mixture by cast polymerization for a significantly shortened time.
Abstract:
Hydrophilic polymers are formed in situ by irradiating a mixture of hydroxyalkyl methacrylate and a cross linking agent. The former polymer is optically clear and free of voids, obviating the discoloration and discontinuity deficiencies characterizing prior art polymerization employing foreign substances such as solvents, dispersing agents, catalysts and the like. In accordance with one aspect of the present invention, the hydrophilic polymer may be formed as a coating on a glass, plastic or other substrate.
Abstract:
STABLE THIN FILM ELECTRETS ARE PRODUCED BY DIRECTING AN ELECTRON BEAM ON A DIELECTRIC MATERIAL IN A CONTROLLED FASHION. ELECTRON ABSORPTION IN THE FILM AND INDUCED SECONDARY EMISSION, BOTH FROM THE FILM AND FROM AN ADJACENT DIELECTRIC SURFACE, AID IN PRODUCING STABLE ELECTRETS WITH SUPERIOR CHARGE CHARACTERISTICS AND VERY LONG LIFETIMES.
Abstract:
The present subject matter relates to processes for irradiating visbroken propylene polymer compositions or extrudates of propylene polymer compositions containing a propylene polymer having a low polydispersity index and a non-phenolic stabilizer.
Abstract:
A filter for visual display terminals (VDT), comprising a substrate film having on one surface a deposition layer of indium-tin oxide (ITO) and on the other surface a flexible resin layer comprising a photopolymerized coating derived from a monomeric mixture of at least one of diallyl phthalate, diallyl isophthalate, and diallyl terephthalate, and pentaerythritol tetra(3-mercaptopropionate) in an equivalent ratio of 2:1 to 1:3, and further containing a photopolymerization initiator.
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:
Fibers as a reinforcing substrate are impregnated with the particles of polytetrafluoroethylene and pressed into a shape at the melting point of polytetrafluoroethylene. Alternatively, the reinforcing substrate sandwiched between polytetrafluoroethylene sheets is pressed into a shape at the melting point of polytetrafluoroethylene. In either case, the shaped article is then exposed to an ionizing radiation in an oxygen-free atmosphere at the melting point of polytetrafluoroethylene. The inherent characteristics of the polytetrafluoroethylene, i.e., heat resistance, chemical resistance, abrasion resistance and lubricity, are retained and yet radiation resistance and resin transparency are imparted.
Abstract:
Multiconstituent fibers prepared from two or more polymers, with at least one of these polymers being randomly dispersed through the fiber, in the form of domains. At least about 40 percent by weight of these domains have one length of at least 20 microns, measured in the direction along the fiber axis, and have another length, measured along the longest line dissecting the domain cross-section in a plane perpendicular to the fiber axis, of at least about 5 percent of the fiber equivalent diameter.