Abstract: The invention relates to hydrophilic fibers and filaments with good coloring response to dyes from filament-forming hydrophobic synthetic polymers having a sheath-core structure with a highly microporous core and a substantially compact sheath and having a water retention capacity of at least 10% wherein the pores in the core have an average pore diameter measured in the direction of the cross-section of the fiber, of at most 4000 A. The invention relates also to a process for the production of those filaments and fibers according to a dry-spinning process wherein a spinning solution is spun below the boiling point of the spinning solvent used.

Abstract: Solutions in substantially anhydrous hydrazine of poly(hydroxymethylene) and copolymers of hydroxymethylene with up to about 30 mol percent of ethylenically unsaturated comonomers are suitable for solution spinning to make filaments, i.e. fibers and film.

Abstract: Disclosed are reverse osmosis anisotropic gel-type membranes having the structure: ##STR1## WHEREIN N IS A WHOLE NUMBER; A is a divalent group derived from piperazine and having the structure: ##STR2## WHEREIN X IS 0 TO 8 AND R is an alkyl group, and Q is at least two divalent organic groups selected from the group consisting of: ##STR3## wherein Y is O or S, ##STR4## Also disclosed are processes for preparing such membranes.

Abstract: Polymeric piperazinamides suitable for use in reverse osmosis membranes. These polymeric piperazineamides consist essentially of the repeating unit ##STR1## wherein x is zero or a whole number from 1 to 8, R is a substituent such as alkyl, and --A-- is a bivalent radical, namely an organic dicarbonyl radical which either is always of the formula ##STR2## wherein X is oxygen or sulfur, and R' and R" are each hydrogen, alkyl, or aryl, or else where some of said radicals --A-- are of formula (III) and the remainder of said radicals --A-- are organic dicarbonyl radicals differing from said formula (III).

Abstract: Polypyrrolidone solutions having a bulk viscosity of 100-10,000 poises, and containing a solvent such as formic acid and a volatile diluent such as methylene chloride, are spun into filaments by extrusion through a spinneret. The solution contains, for example, about 5-40 weight percent of polypyrrolidone, about 30-90 weight percent of formic acid and about 5-60 weight percent of methylene chloride.

Abstract: Water swellable absorbent articles, made from solutions of carboxylic polyelectrolytes, together with methods for their preparation, and a composition useful to make said articles are disclosed. The articles are cured and/or crosslinked with polyamide-polyamine epichlorohydrin adducts by heating and/or removing subsantially all of the solvent from the precursor composition.The absorbent articles are useful as surgical sponges, diapers, tampons, meat trays, bath mats and the like.

Abstract: Method of preparing films of acrylonitrile polymer exhibiting very high tensile strength, stiffness, optical clarity, and outstanding gas barrier properties. Method entails extruding a hot, concentrated solution of said polymer in a solvent therefor that is water-soluble, e.g., dimethyl sulfoxide, onto a film-supporting surface, e.g., a flat surface, or a drum, which, preferably, has a low energy surface such as provided by wetting the surface with aqueous dimethyl sulfoxide, or coated with polytetrafluoroethylene, or other suitable means to thereby form a film. The resulting film is then contacted with an aqueous medium, e.g., water to remove the solvent (e.g., dimethyl sulfoxide) and partially replace it with water, this treatment being effected under conditions that will prevent the film from curling or puckering. The resulting film is composed essentially of acrylonitrile polymer and water, and is ignition resistant.

Abstract: A process is described for the isolation, in a solid state, of polyimides particularly those prepared by interaction of a polyisocyanate and a polycarboxylic anhydride in an organic solvent. A solution of the polyimide is passed into water preferably in the form of droplets or as extruded thin strands. The droplets or strands can be chopped, ground or otherwise comminuted after solidification. The process is particularly applicable to the isolation of solvent-soluble polyimides prepared by reaction of benzophenone tetracarboxylic dianhydride with a mixture of methylenebis(phenyl isocyanate) and toluene diisocyanate.

Abstract: The manufacture of ion-exchanging shaped articles, in particular fibers, fabrics and membranes, by polymerization of the polymerizable monomers of a homogeneous mixture of a polyolefin, a vinylaromatic compound, an aromatic divinyl compound and a solvent of low volatility, converting said mixture to a shaped article, removing the said solvent and introducing ion-exchanging groups into the said shaped article.

Abstract: Fibers and yarn and a process for preparing them comprising dissolving in concentrated sulfuric acid a polymer containing at least 75 mol percent of an aromatic poly-(1,3,4-oxadiazole) having the repeating structural formul a ##SPC1##In which Ar is ##SPC2## the benzene rings in A or B being substituted or unsubstituted; the linking bonds in A being situated m- or p- with respect to each other, and in B situated m- or p- with respect to X; X being --SO.sub.2 -- or --CO--; and n being 1 or 2. The solution is then spun through a spinneret into a substantially water-free precipitating medium of at least one liquid having the formula (II) ##EQU1## IN WHICH R.sub.1, R.sub.2 and R.sub.3 may be the same or different and are alkyl groups having 1 to 4 carbon atoms, and R.sub.3 may also be H, and in which R.sub.1 and R.sub.2 or R.sub.1 and R.sub.3 may together comprise a divalent alkylene radical, the total number of carbon atoms in R.sub.1, R.sub.2 and R.sub.

Abstract: Process for dyeing substantially undrawn dry-spun filaments of acrylonitrile polymer which comprises extracting spinning solvent from moistened dry-spun filaments of acrylonitrile polymer to below 10% by weight of the filaments and at below 80.degree.C., dyeing the extracted filaments in a dye bath at below 80.degree.C. by initially contacting the filaments with the dye at nearly zero stretch, followed by stretching the filaments from 1.5.times. to 4.5.times. at between 60.degree. - 80.degree.C. while still contacting the dye solution.