Abstract: A melt-spun highly oriented and crystalline thermoplastic filament or fiber having a tenacity of at least about 10 g/d, an elongation less than about 15%, and a modulus of at least about 130 g/d. A method of making highly oriented and crystalline thermoplastic filaments has been developed that comprises extruding a thermoplastic polymer to form at least one molten filament. The at least one molten filament is introduced into a horizontal liquid isothermal bath. The bath is maintained at a temperature between the glass transition temperature and the melting temperature of the thermoplastic polymer. The bath increases the tension along the molten filament to form at least one partially oriented and low crystalline filament. The partially oriented filament is drawn to form the highly oriented and crystalline filament.

Abstract: A melt-spun highly oriented and crystalline thermoplastic filament or fiber having a tenacity of at least about 10 g/d, an elongation less than about 15-%, and a modulus of at least about 130 g/d. A method of making highly oriented and crystalline thermoplastic filaments has been developed that comprises extruding a thermoplastic polymer to form at least one molten filament. The at least one molten filament is introduced into a horizontal liquid isothermal bath. The bath is maintained at a temperature between the glass transition temperature and the melting temperature of the thermoplastic polymer. The bath increases the tension along the molten filament to form at least one partially oriented and low crystalline filament. The partially oriented filament is drawn to form the highly oriented and crystalline filament.

Abstract: A melt-spun highly oriented and crystalline thermoplastic filament or fiber having a tenacity of at least about 10 g/d, an elongation less than about 15-%, and a modulus of at least about 130 g/d. A method of making highly oriented and crystalline thermoplastic filaments has been developed that comprises extruding a thermoplastic polymer to form at least one molten filament. The at least one molten filament is introduced into a horizontal liquid isothermal bath. The bath is maintained at a temperature between the glass transition temperature and the melting temperature of the thermoplastic polymer. The bath increases the tension along the molten filament to form at least one partially oriented and low crystalline filament. The partially oriented filament is drawn to form the highly oriented and crystalline filament.

Abstract: A process for preparing high initial modulus and high tensile strength polyamide fibers is described. The process comprises complexing the polyamide with a Lewis acid, dry-jet wet spinning the complexed fibers, drying the spun fibers for a period of time, drawing the fibers, and soaking the fibers in solvent to remove the Lewis acid. High molecular weight nylon 6,6 fibers prepared according to the described process show initial moduli of up to 30.1 GPa and tenacities of up to 2.5 GPa.

Abstract: A process for preparing high initial modulus and high tensile strength polyamide fibers is described. The process comprises complexing the polyamide with a Lewis acid, dry-jet wet spinning the complexed fibers, drying the spun fibers for a period of time, drawing the fibers, and soaking the fibers in solvent to remove the. Lewis acid. High molecular weight nylon 6,6 fibers prepared according to the described process show initial moduli of up to 30.1 GPa and tenacities of up to 2.5 GPa.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions in the reactor zone to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. A spinneret zone downstream of the reactor zone thus receives the molten polycaprolactam directly from the reactor zone and forms a fiber therefrom by extruding it through the spinneret's fiber-spinning orifice.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: Continuous anionic polymerization and melt-spinning of a polycaprolactam includes forming a reaction mixture by bringing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator into contact with one another, and then subjecting the reaction mixture to anionic polymerization reaction conditions to obtain a molten polycaprolactam. The molten polycaprolactam is the directly (i.e., without intermediate solidification) transferred to, and extruded through, a fiber-forming orifice of a spinneret to form a fiber thereof. One exemplary system to achieve such continuous anionic polymerization and melt-spinning of polycaprolactam includes a mixer for receiving and mixing at least two streams of liquid caprolactam respectively containing a polymerization initiator and co-initiator, and a reactor and melt-spinning apparatus downstream of the mixer.

Abstract: A process for producing hollow polyamide filaments having at least one continuous void that adds to a fiber-forming polyamide from about 0.05% to about 5% of a triazine compound prior to extrusion of fiber. The process results in a greater closure of voids and larger void space than when the triazine compound is not used.

Abstract: .epsilon.-Caprolactam is continuously recovered from carpet made from nylon 6 face fibers and a backing. The carpet is fed to a separator to prepare scrap containing nylon 6 and auxiliary materials. The scrap from the separator is fed to a depolymerizing reactor to produce an .epsilon.-caprolactam containing distillate and more auxiliary materials. The .epsilon.-caprolactam in the distillate is separated from other volatiles and purified. The auxiliary materials are also recovered or re-used.

Abstract: Disclosed is a fiber-forming polymer blend, comprising:a) a polyamide;b) a miscible amorphous polymer; andc) an immiscible amorphous polymer.

Abstract: Disclosed is a fiber-forming polymer blend, comprising:a) a polyamide;b) a miscible amorphous polymer; andc) an immiscible amorphous polymer.

Abstract: Disclosed is a fiber-forming polymer blend, comprising:a) a polyamide;b) a miscible amorphous polymer; andc) an immiscible amorphous polymer.

Abstract: Disclosed is a fiber-forming polymer blend, comprising:a) a polyamide;b) a miscible amorphous polymer; andc) an immiscible amorphous polymer.

Abstract: Polyamide is semi-continuously depolymerized by: (a) charging the polyamide to a depolymerization reactor containing 5 to 50% by weight of an unpolymerized catalyst; (b) melting the polyamide and subjecting the resultant melt to a flow of superheated steam to obtain a steam distillate; (c) separating amide monomers in the distillate from other volatiles therein; (d) when conversion to amide monomers is 40 to 90% complete, recharging polyamide to the depolymerization reactor; and (e) repeating steps (a)-(d) until a desired amount of polyamide is depolymerized.

Abstract: A multilobal synthetic polymeric filament has a single approximately axially extending central void. The total cross-sectional void area of the filament is between about 3 and about 10 percent void.