Polymer foamed fiber, and preparation method and use thereof

Abstract

Provided are a polymer foamed fiber and a preparation method thereof. The polymer foamed fiber has a closed-pore structure in an interior, the closed-pore structure comprises uniform and dense pores and an average pore size of the pores in the closed-pore structure is in a range of from 1 μm to 50 μm. The polymer foamed fiber has a diameter in a range of from 0.08 mm to 1.0 mm with an average deviation of the diameter of ±0.05 mm, a skin layer thickness in a range of from 0 to 0.1 mm, a density in a range of from 0.30 g/cm3 to 0.90 g/cm3, and an elongation at break in a range of from 0 to 600%. The polymer foamed fiber has advantages, such as, light weight, uniform fiber thickness, a porous structure, dense internal pores with uniform pore sizes and a controllable skin layer thickness.

1 . A polymer foamed fiber, wherein the polymer foamed fiber has a closed-pore structure in an interior, the closed-pore structure comprises uniform and dense pores and an average pore size of the pores in the closed-pore structure is in a range of from 1 μm to 50 μm; a diameter of the polymer foaming fiber is in a range of from 0.08 mm to 1.0 mm with an average deviation of the diameter of ±0.05 mm, a skin layer thickness of the polymer foamed fiber is in a range of from 0 to 0.1 mm, a density of the polymer foamed fiber is in a range of from 0.30 g/cm 3  to 0.90 g/cm 3 , and an elongation at break of the polymer foamed fiber is in a range of from 0 to 600%. 
     
     
         2 . The polymer foamed fiber according to  claim 1 , wherein the polymer foamed fiber comprises following components in parts by weight: 90-100 parts of a polymer, 1-10 parts of a nucleating agent, 0-1 parts of a chain extender, and 0-0.5 parts of an antioxidant. 
     
     
         3 . The polymer foamed fiber according to  claim 2 , wherein the polymer foamed fiber satisfies at least one of following items:
 (1) a melting point of the polymer is in a range of from 100° C. to 230° C. and a hardness of the polymer is in a range of from Shore 60A to Shore 64D;   (2) the polymer comprises one or more of a thermoplastic elastomer, polylactic acid, polypropylene, nylon and polyethylene terephthalate;   (3) the nucleating agent comprises at least one of calcium carbonate, talc, mica, montmorillonite, nano-silica, carbon black, and a carbon nanotube;   (4) the chain extender comprises at least one of a bisoxazoline chain extender and an epoxy chain extender;   (5) the antioxidant comprises at least one of an amine antioxidant and a phosphorus-containing antioxidant.   
     
     
         4 . A preparation method of the polymer foamed fiber according to  claim 2 , comprising following steps:
 S1, premixing all components to obtain a mixture, subjecting the mixture to drying, melt extrusion and cooling to obtain a polymer fiber filament, and winding the polymer fiber filament to obtain a polymer fiber filament coil;   S2, immersing the polymer fiber filament coil in a polyvinyl alcohol solution to form a barrier layer, then evenly sticking an inorganic filler to the barrier layer to form an isolation layer, so as to obtain a primary product of the polymer foamed fiber;   S3, impregnating the primary product of the polymer foamed fiber in a supercritical fluid, conditionally inducing the primary product of the polymer foamed fiber to foam so as to obtain an induced polymer fiber; taking out the induced polymer fiber and subjecting the induced polymer fiber to pulling, rinsing, drying, and rewinding to obtain the polymer foamed fiber.   
     
     
         5 . The preparation method according to  claim 4 , wherein the preparation method satisfies at least one of following items:
 (1) the drying in step S1 is hot air drying, and a moisture content of the mixture after drying is less than 0.05 wt. %;   (2) the melt extrusion in step S1 is performed by using a twin-screw extruder, and temperatures from a feed port to an extrusion head of the twin-screw extruder are set to be 80° C., 180° C., 190° C., 205° C., 215° C., 180-190° C.;   (3) a winding speed for winding the polymer fiber filament in step S1 is in a range of from 0.5 m/s to 2 m/s;   (4) a diameter of the polymer fiber filament in step S1 is in a range of from 0.10 mm to 0.80 mm;   (5) an interval of coating time between the barrier layer and the isolation layer in step S2 is in a range of from 10 s to 20 s.   
     
     
         6 . The preparation method according to  claim 4 , wherein the polyvinyl alcohol solution in step S2 comprises following components in percentage by weight: 5-10 wt. % of polyvinyl alcohol (PVA), 70-80 wt. % of deionized water, 3-10 wt. % of hydrolyzed starch, and 3-10 wt. % of gypsum. 
     
     
         7 . The preparation method according to  claim 6 , wherein a molecular weight of the polyvinyl alcohol is in a range of from 30,000 to 200,000, and an alcoholysis degree of the polyvinyl alcohol is 99%. 
     
     
         8 . The preparation method according to  claim 4 , wherein the inorganic filler comprises at least one of talc powder, graphene, micro-nano calcium carbonate, and nano silicon dioxide; and a particle size of the inorganic filler is in a range of from 0.2 μm to 10 μm. 
     
     
         9 . The preparation method according to  claim 4 , wherein the preparation method satisfies at least one of following items:
 (1) the supercritical fluid in step S3 comprises one of supercritical CO 2 , supercritical N 2 , and a mixed fluid of supercritical CO 2  and supercritical N 2 ;   (2) a solubility of the supercritical fluid in the primary product of the polymer foamed fiber in step S3 is in a range of from 0.5 wt. % to 5.0 wt. %;   (3) a hardness of the primary product of the polymer foamed fiber in step S3 is in a range of from Shore 80A to Shore 64D;   (4) impregnating the primary product of the polymer foamed fiber in the supercritical fluid in step S3 is performed under a condition that a pressure is in a range of from 10 Mpa to 20 Mpa and a temperature is in a range of from 70° C. to 120° C.;   (5) conditionally inducing the primary product of the polymer foamed fiber to foam is performed in a condition that the pressure and the temperature are rapidly changed, wherein a change rate for the pressure is in a range of from 10 Mpa/s to 15 Mpa/s and a change rate for the temperature is in a range of from 0 to 80° C./s;   (6) rinsing the induced polymer fiber in step S3 is performed with water, and a flow rate of the water is in a range of from 0 to 1 m/s and a rinsing time is in a range of from 0 to 30 s.   
     
     
         10 . A preparation method of the polymer foamed fiber according to  claim 3 , comprising following steps:
 S1, premixing all components to obtain a mixture, subjecting the mixture to drying, melt extrusion and cooling to obtain a polymer fiber filament, and winding the polymer fiber filament to obtain a polymer fiber filament coil;   S2, immersing the polymer fiber filament coil in a polyvinyl alcohol solution to form a barrier layer, then adhering an inorganic filler to the barrier layer to form an isolation layer, so as to obtain a primary product of the polymer foamed fiber;   S3, impregnating the primary product of the polymer foamed fiber in a supercritical fluid, conditionally inducing the primary product of the polymer foamed fiber to foam so as to obtain an induced polymer fiber; taking out the induced polymer fiber and subjecting the induced polymer fiber to pulling, rinsing, drying, and rewinding to obtain the polymer foamed fiber.