Abstract: A process for preparing a PANOX fiber comprising: obtaining an acrylonitrile copolymer, wherein the copolymer contains at least about 2% by weight itaconic acid comonomer; forming a spin dope from the copolymer; wet spinning the spin dope to obtain gelled filaments; contacting the gelled filaments with ammonia activator in an aqueous imbibation bath; bundling the gelled filaments to obtain a fiber; removing solvent from the fiber; drawing the fiber; densifying the fiber by heating the fiber up to about 400 degrees C. for a time of about 15 minutes in a rapid densification zone; and withdrawing a PANOX fiber from the densification zone.

Abstract: A process for preparing a PANOX fiber comprising: obtaining an acrylonitrile copolymer, wherein the copolymer contains at least about 2% by weight itaconic acid comonomer; forming a spin dope from the copolymer; wet spinning the spin dope to obtain gelled filaments; contacting the gelled filaments with ammonia activator in an aqueous imbibation bath; bundling the gelled filaments to obtain a fiber; removing solvent from the fiber; drawing the fiber; densifying the fiber by heating the fiber up to about 400 degrees C. for a time of about 15 minutes in a rapid densification zone; and withdrawing a PANOX fiber from the densification zone.

Abstract: A process for preparing a PANOX fiber comprising: obtaining an acrylonitrile copolymer, wherein the copolymer contains at least about 2% by weight itaconic acid comonomer; forming a spin dope from the copolymer; wet spinning the spin dope to obtain gelled filaments; contacting the gelled filaments with ammonia activator in an aqueous imbibation bath; bundling the gelled filaments to obtain a fiber; removing solvent from the fiber; drawing the fiber; densifying the fiber by heating the fiber up to about 400 degrees C. for a time of about 15 minutes in a rapid densification zone; and withdrawing a PANOX fiber from the densification zone.

Abstract: A process for preparing a PANOX fiber comprising: obtaining an acrylonitrile copolymer, wherein the copolymer contains at least about 2% by weight itaconic acid comonomer; forming a spin dope from the copolymer; wet spinning the spin dope to obtain gelled filaments; contacting the gelled filaments with ammonia activator in an aqueous imbibation bath; bundling the gelled filaments to obtain a fiber; removing solvent from the fiber; drawing the fiber; densifying the fiber by heating the fiber up to about 400 degrees C. for a time of about 15 minutes in a rapid densification zone; and withdrawing a PANOX fiber from the densification zone.

Abstract: A process for preparing superior carbon fiber including a step of rapid imbibation of densification activator from an aqueous bath; and product prepared therefrom.

Abstract: A process for preparing a PANOX fiber comprising: obtaining an acrylonitrile copolymer, wherein the copolymer contains at least about 2% by weight itaconic acid comonomer; forming a spin dope from the copolymer; wet spinning the spin dope to obtain gelled filaments; contacting the gelled filaments with ammonia activator in an aqueous imbibation bath; bundling the gelled filaments to obtain a fiber; removing solvent from the fiber; drawing the fiber; densifying the fiber by heating the fiber up to about 400 degrees C. for a time of about 15 minutes in a rapid densification zone; and withdrawing a PANOX fiber from the densification zone.

Abstract: A process for preparing superior carbon fiber including a step of rapid imbibation of densification activator from an aqueous bath; and product prepared therefrom.

Abstract: Melt spun thermoplastic polyurethane polymers useful as textile fibers and having good tenacity and recovery and substantially no gelation are disclosed. The polymers are prepared by a three-step polymerization process including: preparation of “hard” segment oligomer, preparation of “soft” segment oligomer and final reaction of “hard” segment with “soft” segment in a twin-screw reaction extruder to obtain a final polyurethane product having relatively uniform distances between the “hard” segments. The “soft” segment oligomer comprises blocks of polymeric glycol (poly) urethanes end capped with isocyanate groups. The “hard” segment oligomer comprises blocks of low molecular weight C2–C6 glycol (poly) urethanes.

Abstract: Melt spun thermoplastic polyurethane polymers useful as textile fibers and having good tenacity and recovery and substantially no gelation are disclosed. The polymers are prepared by a three-step polymerization process including: preparation of “hard” segment oligomer, preparation of “soft” segment oligomer and final reaction of “hard” segment with “soft” segment in a twin-screw reaction extruder to obtain a final polyurethane product having relatively uniform distances between the “hard” segments. The “soft” segment oligomer comprises blocks of polymeric glycol (poly) urethanes end capped with isocyanate groups. The “hard” segment oligomer comprises blocks of low molecular weight C2-C6 glycol (poly) urethanes.