Abstract:
Polypropylene (PP) membranes having a hydrophilic surface have been prepared by extracting a fugitive hydrophilic pore-forming agent from a gelled film prepared by evaporating the solvent from a homogeneous solution of isotactic polypropylene, functionalized polypropylene an the fugitive agent in a solvent, such as xylene. Most of the functional groups, such as --OH, --NH.sub.2 and --COOH, in the functionalized polypropylene are located on the surfaces of the membrane, including pore surfaces. The resulting membranes, especially membranes having an asymmetric structure, are useful for ultrafiltration, dialysis and/or microfiltration.
Abstract:
Molding composition based on fluoropolymers and process for producing foam material therefrom The invention relates to a molding composition based on fluoropolymers which additionally contain from 1 to 50% by weight of at least one polymer containing sulfoxide groups. The polymer containing sulfoxide groups comprises, in particular, polyarylene sulfoxide units of the formula: --(--C.sub.6 H.sub.4 --SO--)--.
Abstract:
A method of forming complex polyimide foam shapes by impregnating a low density, open cell, reticulated form with polymide foam precursor, placing the combination in a mold, closing the mold, then heating the assembly to the foaming and curing temperatures of the precursor. As the powdered precursor expands, it spreads throughout the reticulated foam producing a product having substantially uniform density and polyimide foam characteristics. If desired, the reticulated foam can be removed from the product by using a material that outgasses and boils away at polyimide processing temperatures. Radar absorbing materials may be incorporated in the reticulated foam so that the final product will have uniformly distributed radar absorbing components with the desirable high temperature resistance and other properties of polyimide foams.
Abstract:
A composition of a coalescible polyimide powder and a polymer of formaldehyde is provided, said composition adapted for fabricating porous polyimide shaped articles by subjecting said composition to a forming pressure of about 100,000 psi to provide a preform, and thereafter sintering said preform by heating said preform to a temperature above about 300*C. to provide a porous polyimide shaped article having interconnecting pores; said porous polyimide shaped articles being useful as, for example, oil-impregnated bearings.
Abstract:
A composition comprising a fiber component having a melt/softening temperature and a matrix material for mixing with the fiber component, wherein the composition experiences a vertical rise of at least about 0.5 mm in the absence of any blowing agent when exposed to an elevated temperature of at least about 70° C.
Abstract:
Provided are graft copolymer particles enabling introduction of adsorptive functional groups adsorbing metals and others, a method for producing same, and an adsorbent using same. (1) Porous graft copolymer particles containing graft chains introduced into porous particles (particle surface having an average pore diameter of 0.01-50 μm) including at least one resin selected from olefin resins, water-insoluble modified polyvinyl alcohol resins, amide resins, cellulosic resins, chitosan resins and (meth)acrylate resins. (2) A method for producing porous graft copolymer particles including (I) melt-kneading a polymer A and a polymer B other than the polymer A to obtain a compound material, (II) extracting and removing the polymer B from the compound material to obtain a porous material of the polymer A, (III) granulating the porous material, and (IV) introducing graft chains into the porous particles. (3) An adsorbent of porous graft copolymer particles.
Abstract:
An embodiment of this invention discloses a method for producing a network texture and the method comprises the steps of: formation of a porous structure as a template (matrix); formation of two coherent, independent, and separated robust continuous network structures within the matrix by using the matrix as the template; softening or removing the matrix to shift the two continuous network structures, leading to a novel network texture comprising two incoherent continuous network structures.
Abstract:
Described herein are absorbent articles and methods of making such articles. The articles are made by bonding a copolymer onto a substrate to form a core. The absorbent articles are particularly useful in personal care product, e.g., disposable hygiene products.
Abstract:
The objective of the present invention is to provide to a method for easily producing high-performance porous cellulose beads having high mechanical strength. Also, the objective of the present invention is to provide an adsorbent produced from the high-performance porous cellulose beads. According to the present invention, high-performance porous cellulose beads can be easily produced from porous cellulose beads, and an adsorbent having high strength and high adsorption amount can be easily produced from the high-performance porous cellulose beads.