Abstract:
A medical device includes a textured surface having a predetermined nanostructure, wherein the nanostructure is less than about 500 nanometers in a broadest dimension. The textures nanostructure surface reduces friction between the medical device and biological tissue.
Abstract:
A method for preparing a polymeric material includes: providing a polymeric matrix having at least one polymer and at least one porogen; and degrading the at least one porogen at a temperature T≦1.1 Tg, where Tg is a glass transition temperature of the polymeric matrix. The degrading step includes exposing the polymeric matrix to thermal degradation, chemical degradation, electrical degradation and/or radiation degradation, wherein the polymeric material has a permeability at least 1.2 times a permeability of the polymeric matrix for a gas, and a selectivity of the polymeric material is at least 0.35 times a selectivity of the polymeric matrix for a gas pair. The method preferably provides gas separation membranes that exceed Robeson's upper bound relationship for at least one gas separation pair. Novel polymeric materials, gas separation membranes and fluid component separation methods are also described.
Abstract:
Carbon steel substrates are protected from corrosive environments by a coating of nonconductive poly(aniline) which has been chemically prepared and cast onto the substrate from solution. The coating can also include other polymers which are miscible with the poly(aniline) but do not protonate it so as to make it conductive. Such polymers can include polyimides, epoxies, and urethane linked diisocyanates, among others. In these blends, a weight composition of at least 5% poly(aniline) to the other polymer is preferred. Overall, the nonconductive form of polyaniline has been found to be more effective in this service than the conductive form. Air oxidation of the poly(aniline) coating before exposure to a corrosive environment enhances the benefits.
Abstract:
An improved papermaking process has been developed to enhance the properties of the resultant paper or paper-type products. The process involves adding a polyvinyl alcohol/vinylamine copolymer along with a crosslinking agent at the dry end step of a conventional papermaking process. Improvements in the properties of the resultant paper products are observed, especially at low levels of copolymer addition.
Abstract:
Ultra-fine polymeric fibers are produced from various polymeric materials by mixing with thermoplastic poly(vinyl alcohol) and extruding the mixture through a die followed by further orientation. The poly(vinyl alcohol) is extracted to yield liberated ultra-fine polymeric fibers. The polymer utilized can include post-consumer polymer waste.
Abstract:
Described are blends of a crystalline poly(aryl ether ketone) and a polyarylate and/or a liquid crystalline polyarylate. These blends exhibit improved mechanical properties and environmental stress rupture resistance.
Abstract:
Injection-moldable copolyesters of terephthalate units, ethylene units and a high proportion (e.g. 82-87) mole %) of oxybenzoate units, and cookware made of such copolyesters. Process for making such copolyesters by reacting polyethylene terephthalate with p-acetoxybenzoic acid in a solvent, first at a temperature below 240.degree. C. to product a fragmented polyester, raising the temperature to split off acetic acid, then adding more acetoxybenzoic acid to raise the oxybenzoate content to more than 80 mole %.
Abstract:
Described herein are isomorphic blends of poly(phenylene oxide) and poly(aryl ether ketones) having less than about 30 mole percent and preferably less than about 25 mole percent of keto groups based on the total keto and ether groups. The blends are particularly desirable for use as an electrical insulation for electrical conductors.
Abstract:
Water or gas containing organic impurities is purified by contact with a poly(trialkylsilylpropyne), such as poly[1-(trimethylsilyl)-1-propyne], operating as a bulk absorbent. Regeneration of the absorbent can be by vacuum or a stream of air.
Abstract:
Described herein is a shaped article formed from a blend of a poly(aryl ether) resin and an aromatic polycarbonate resin and/or a polycarbonate resin. An article molded from such a blend has improved hydrolytic stability as compared with an article molded from the constitutent components of the blend.