Abstract:
The present invention concerns methods for removing sulfur from yarn comprising the steps of: a) contacting never-dried polymeric yarn with an aqueous base, the polymer comprising imidazole groups and said polymer comprising sulfur atoms characterized as being in the form of sulfate anions; b) contacting the yarn with an aqueous acid solution of pH 5 or lower; and c) rinsing the yarn.
Abstract:
The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: a) contacting never-dried sulfate anion-containing polymeric-fiber with an halide-containing acid to displace at least a portion of the sulfate ions with halide anions; and b) rinsing the fiber to remove the displaced sulfate ions.
Abstract:
Disclosed are processes for preparing polyareneazole polymers characterized as providing polymer solutions having an inherent viscosity of at least about 22 dl/g at 30° C. at a polymer concentration of 0.05 g/dl in methane sulfonic acid. Polyareneazoles, filaments and yarns are also disclosed.
Abstract:
Disclosed are processes for preparing polyareneazole polymers that include contacting, in polyphosphoric acid, azole-forming monomers and metal powder, the metal powder added in an amount of from about 0.05 to about 0.9 weight percent, based on the total weight of the azole-forming monomers, and reacting the azole-forming monomers to form the polyareneazole polymers. Polyareneazoles, filaments and yarns are also disclosed.
Abstract:
Spun yarns are made at high speeds of up to 220 meters per minute, using spinning techniques in which air is used to twist the fibers of a three component blend, one component of which consists of staple fibers made from electrically conductive filaments having a denier no greater than 2.5 times the denier of the filaments of the other components.
Abstract:
The present invention concerns fiber made from a polymer comprising imidazole groups, the polymer further having: i) halide anions being present in an amount in the range of 0.05 to 20.1 weight percent, based on weight of fiber; ii) sulfur, wherein the sulfur is present in the fiber in an amount in the range of 0.05 to 3 weight percent, based on weight of fiber; and iii) alkali metal ion, wherein the alkali metal ion is present in the fiber in an amount in the range of 0.05 to 2 weight percent, based on weight of fiber.
Abstract:
The present invention concerns methods for removing sulfur from yarn comprising the steps of: a) contacting never-dried polymeric yarn with an aqueous base, the polymer comprising imidazole groups and said polymer comprising sulfur atoms characterized as being in the form of sulfate anions; b) contacting the yarn with an aqueous acid solution of pH 5 or lower; and c) rinsing the yarn.
Abstract:
The present invention concerns methods for removing sulfur from a fiber comprising the steps of: a) contacting never-dried sulfur-containing fiber in a yarn with an aqueous base having a pKa less than or equal to 11 to release at least a portion of said sulfur, said sulfur comprising, at least in part, sulfate anions and said yarn comprising fiber derived from polymer comprising imidazole groups; and b) rinsing said yarn to remove at least a portion of released sulfur.
Abstract:
The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: contacting never-dried sulfate anion-containing polymeric-fiber with an aqueous acid having a pKa of less than 5 to displace at least a portion of the sulfate anions; and b) rinsing the fiber to remove the displaced sulfate ions.
Abstract:
The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: a) contacting never-dried sulfate anion containing polymeric-fiber with an aqueous salt solution comprising halide anions to displace at least a portion of the sulfate anions with halide anions; and b) rinsing the fiber to remove displaced sulfate anions.