CN112316746B - Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof - Google Patents
Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof Download PDFInfo
- Publication number
- CN112316746B CN112316746B CN202010941528.4A CN202010941528A CN112316746B CN 112316746 B CN112316746 B CN 112316746B CN 202010941528 A CN202010941528 A CN 202010941528A CN 112316746 B CN112316746 B CN 112316746B
- Authority
- CN
- China
- Prior art keywords
- molecular weight
- hollow fiber
- fiber membrane
- weight polyethylene
- ultra
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/26—Polyalkenes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/08—Hollow fibre membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/02—Details relating to pores or porosity of the membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/48—Antimicrobial properties
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Artificial Filaments (AREA)
Abstract
The invention discloses an ultra-high molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution, which comprises the following steps: (1) Mixing the ultrahigh molecular weight polyethylene with a solvent, a water-soluble salt pore-foaming agent, an auxiliary additive and the like according to a certain ratio to prepare the ultrahigh molecular weight polyethylene jelly; (2) The hollow fiber membrane with bimodal pore size distribution is prepared by the procedures of extruding, solidifying, removing a solvent, removing a water-soluble salt pore-forming agent, drying, hot stretching and the like of the obtained ultra-high molecular weight polyethylene gel. The ultra-high molecular weight polyethylene hollow fiber membrane with the bimodal pore size distribution has the advantages that the small-pore-size micropores endow the material with high-efficiency interception and filtration performance, and the large-pore-size micropores reduce the flow resistance of filtrate and improve the water flux. Meanwhile, an antibacterial agent can be added to inhibit the breeding of microorganisms and reduce the risk of micropore blockage.
Description
Technical Field
The invention belongs to the technical field of membrane separation, and particularly relates to an ultrahigh molecular weight polyethylene hollow fiber membrane with an antibacterial function and bimodal pore size distribution and a preparation method thereof.
Background
Ultra-high molecular weight polyethylene (UHMWPE) refers to a special polyethylene (ISO 11542) with a molecular weight of more than 150 ten thousand, which has superior impact resistance, crack resistance, low temperature resistance, chemical corrosion resistance and wear resistance. The hollow fiber membrane prepared by using the ultra-high molecular weight polyethylene has the advantages of uniform aperture, good separation performance and high strength, and can be widely applied to the fields of wastewater treatment, seawater desalination, biomedicine, petrochemical industry, pharmacy and the like.
CN102743977A discloses an ultra-high molecular weight polyethylene hollow fiber membrane, which has a monomodal distribution pore diameter with an adjustable average size of 0.05-17 um, but when the membrane is applied in the separation and purification field, high water flux and high rejection rate cannot be obtained at the same time, and it is difficult to improve the separation rate and the purification quality at the same time.
In addition, because a large amount of microorganisms exist in the wastewater, the microorganisms are bred on the hollow fiber membrane to cause the blockage of micropores, the cleaning frequency is increased, and the service life is shortened.
Therefore, it is necessary to develop a hollow fiber membrane that can be applied to the field of separation and purification, and that can ensure both high water flux and high rejection rate.
Disclosure of Invention
The invention aims to provide a preparation method of an ultra-high molecular weight polyethylene hollow fiber membrane with high water flux and high rejection rate, which is applied to the field of separation and purification and can improve the separation rate and the purification quality at the same time.
The technical scheme adopted by the invention is as follows: an ultra-high molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution is prepared by the following steps:
(1) Mixing the ultrahigh molecular weight polyethylene with a solvent, a water-soluble salt pore-foaming agent, an auxiliary additive and the like according to a certain ratio to prepare the ultrahigh molecular weight polyethylene jelly;
(2) The obtained ultra-high molecular weight polyethylene gel is extruded by a double-screw extruder and a tubular hollow spinneret, and then is solidified, desolventized, water-soluble salt pore-forming agent removed, dried, hot stretched and the like to prepare the hollow fiber membrane with bimodal pore size distribution.
Wherein, the ultra-high molecular weight polyethylene in the step (1) is powdery particles with the viscosity average molecular weight of 150-500 ten thousand, preferably the molecular weight is about 300 ten thousand, the particle diameter is 5-500 μm, preferably 50-100 μm, and the mass fraction in the ultra-high molecular weight polyethylene jelly is 5-40 wt%, preferably 10-20 wt%.
Wherein, the solvent in the step (1) is an organic solvent which can be volatilized and removed at high temperature and can dissolve the ultra-high molecular weight polyethylene, such as one or more of decalin, tetralin, xylene and the like, preferably decalin, and the mass fraction of the solvent in the ultra-high molecular weight polyethylene jelly is 40-80 wt%.
Wherein, the water-soluble salt pore-foaming agent in the step (1) is one or more of sodium chloride, disodium hydrogen phosphate, sodium sulfate, potassium chloride and potassium sulfate, the average particle size is 5-100 μm, preferably 10-50 μm, and the mass fraction in the ultra-high molecular weight polyethylene gel is 10-50 wt%.
Wherein, the auxiliary additive in the step (1) comprises one or more of the following materials:
(1) The hydrophilic modifier is one or more selected from powdery ethylene-vinyl alcohol copolymer, polyethylene grafted maleic anhydride, polyvinylpyrrolidone and polyvinyl alcohol, the particle size is 5-100 mu m, preferably 30-50 mu m, and the mass fraction of the hydrophilic modifier in the ultra-high molecular weight polyethylene jelly is 0-5 wt%;
(2) The reinforcing agent is selected from one or more of carbon fiber, graphene, carbon nano tube, calcium carbonate and silicon dioxide, and the mass fraction of the reinforcing agent in the ultra-high molecular weight polyethylene jelly is 0-5 wt%;
(3) The antioxidant is selected from one or more of antioxidant 168, antioxidant 1010, antioxidant 1076 and antioxidant 1098, and accounts for 0.1-1 wt% of the ultra-high molecular weight polyethylene gel.
Wherein, as a preferred technical scheme, the step (1) can also be added with an antibacterial agent which is one or more selected from silver ion antibacterial agents, cobalt ion antibacterial agents, zinc ion antibacterial agents and copper ion antibacterial agents, preferably silver ion antibacterial agents, and the mass fraction of the silver ion antibacterial agents in the ultra-high molecular weight polyethylene jelly is 0.05-2 wt%.
In the step (1), the ultra-high molecular weight polyethylene gel is prepared by uniformly mixing raw materials in a normal-temperature mixing kettle and then introducing the mixture into a high-temperature mixing kettle for swelling. The mixing temperature of the high-temperature mixing kettle is 120-160 ℃, the mixing time is 10-100 min, and the mixing rotating speed is 10-100 rpm.
Wherein in the step (2), the extrusion temperature of the double screws is 180-250 ℃, and the rotating speed is 60-400 rpm;
the inner core and the outer core of the tubular hollow spinneret are respectively metal round tubes with the diameter of 1-10 mm and 1.5-15 mm, air or inert gases such as nitrogen, helium, argon and the like at the temperature of 30-90 ℃ can be introduced into the inner core of the tube sleeve, and the number of holes of the spinneret is 1-12;
the curing process is carried out in an air circulation air box, the temperature of the air box can be adjusted between 30 and 150 ℃ so as to control the thermal phase separation process of the ultrahigh molecular weight polyethylene and the solvent, and the size of the micropores is obtained through adjustment;
the solvent removing process adopts a one-stage or multi-stage thermal drying oven, and the temperature of the drying oven is 40-80 ℃;
in order to improve the dissolution and precipitation rate of the water-soluble salt pore-forming agent so as to realize the continuous production of the hollow fiber membrane, the pore-forming agent removing process adopts a circulating water tank for applying ultrasonic waves, the water temperature is 30-60 ℃, the ultrasonic wave power is 1-10 kW, and the frequency is 10-25 KHz;
the drying procedure adopts a one-stage or multi-stage drying oven, and the temperature of the drying oven is 40-80 ℃;
the hot stretching process adopts a multi-stage stretching roller, the roller temperature is 30-110 ℃, the stretching ratio is 1-5 times, preferably 2-3 times, and preferably, air exhaust facilities are added in all devices to reduce the pollution of the solvent to the environment.
The technical principle of the invention is as follows: for hollow fiber membranes, increasing the pore size is beneficial for increasing water flux, but reduces rejection rate and deteriorates filtration purification quality; the reduction in pore size is beneficial for increasing rejection, but reduces water flux, weakens filtration efficiency, and increases the risk of pore blockage. The invention prepares the ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution, the small pore size micropores endow the material with high-efficiency interception and filtration performance, and the large pore size micropores reduce the flow resistance of filtrate and improve water flux. Meanwhile, an antibacterial agent can be added to inhibit the breeding of microorganisms and reduce the risk of micropore blockage.
Preferably, the prepared hollow fiber membrane has an outer diameter of 0.3-10 mm, an inner diameter of 0.1-9.5 mm and a porosity of 50-90%, wherein the pore diameter of the micropores obtained by the desolvation thermal phase separation method is 0.05-3 μm, the pore diameter of the micropores obtained by the desalination leaching method is 2-100 μm, and preferably, the volume ratio of the desolvation pores to the desalination pores is 1-5. The pure water flux is 1-1500L/m 2 H.bar, the retention rate is 75-90%, and the antibacterial rate can reach 99%.
The invention can continuously produce the antibacterial hollow fiber membrane with high water flux and high retention rate, and has simple manufacturing method, low cost and high performance adjustability.
Drawings
FIG. 1 is a schematic diagram of an apparatus used in the practice of the present invention;
FIG. 2 is an electron microscope photograph showing the cross-sectional pore structure of the hollow fiber membrane prepared in example 1 of the present invention.
Detailed Description
In order to better illustrate the application of the present invention, the following examples are further provided to illustrate the content of the present invention, but the application of the present invention is not limited to the following examples.
The performance test method comprises the following steps: test references on porosity, water flux and rejection of hollow fiber membranes, namely preparation and performance studies on ultra-high relative molecular mass polyethylene hollow fiber membranes [ D ] 2014, include the following detailed methods:
testing the porosity of the hollow fiber membrane: porosity of the membrane A k Defined as the specific gravity occupied by pore volume throughout the hollow fiber membrane. Taking out the hollow fiber membrane with a certain length from the absolute ethyl alcohol, wiping the surface free absolute ethyl alcohol with filter paper, and weighing to be omega 0 And then dried in an oven at 40 ℃ for 24 hours and then weighed again as ω, the porosity a of the hollow fiber membrane was calculated from the following formula (1) k 。
Wherein ρ is the average density of UHMWPE (0.935 g/cm) 3 )；
The density of absolute ethanol (0.789 g/cm 3).
And (3) testing the water flux of the hollow fiber membrane: taking out a hollow fiber membrane with a certain length from absolute ethyl alcohol, putting the hollow fiber membrane into a self-made membrane module, applying water pressure of 0.05MPa, recording the quality of pure water passing through the microporous membrane once every certain time, and taking 10 timesOn average, the water flux J (L/m) of the hollow fiber membrane was calculated from the following formula (2) 2 ·h)。
Wherein V is the volume of pure water passing through the membrane during time t (L), S is the membrane area through which water passes, and t is the measurement time (h).
And (3) testing bovine serum albumin retention rate of the hollow fiber membrane: preparing 1g/L Bovine Serum Albumin (BSA) solution, measuring the absorbance of BSA stock solution, penetrating fluid passing through the hollow fiber membrane and refluxing solution by an ultraviolet spectrophotometer, and calculating the retention rate R of the membrane according to the following formula (3).
In the formula, c 0 The absorbance of the BSA stock solution; c. C 1 Absorbance of the refluxed BSA solution; c. C 2 Absorbance of the BSA solution was measured.
And (3) testing the antibacterial rate: reference patent CN100395009C uses escherichia coli and staphylococcus aureus to evaluate the antibacterial properties of hollow fiber membranes.
Anionic-based antibacterial agents used in the examples: zirconium phosphate silver-carrying antibacterial agent, produced by the science and technology of Jinda.
Example 1
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 15wt%; sodium chloride particles: the average grain diameter is 10 mu m, and the content is 25wt%; decalin: the content was 58.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: the content was 0.1wt%.
The preparation method comprises the following steps:
the technological process shown in figure 1 is adopted, (1) ultra-high molecular weight polyethylene, sodium chloride, decalin, an antioxidant and an antibacterial agent are stirred and mixed in a stirring kettle 1 for 10min at normal temperature, and the rotating speed of a stirring paddle is 60rpm; introducing the uniformly mixed solution in the stirring kettle 1 into the stirring kettle 2, stirring and swelling for 10min to prepare the ultra-high molecular weight polyethylene gel, wherein the temperature is 140 ℃, and the rotating speed is 60rpm;
introducing the ultra-high molecular weight polyethylene gel in the stirring kettle 2 into a hopper for storage, wherein the temperature of the hopper is 140 ℃; the ultra-high molecular weight polyethylene jelly in the hopper is extruded by a double screw through a tubular single-hole spinneret, the extrusion temperature is 180-250 ℃, and the rotating speed of the screw is 200rpm. The diameter of the outer core of the spinning nozzle is 7mm, the diameter of the inner core is 5mm, air at 80 ℃ is introduced into the inner core, and the air flow is 2L/min;
(2) Cooling the protofilament extruded by the single-hole spinneret by a cooling air box, wherein the temperature of the air box is 115 ℃; then removing the solvent through a solvent removal oven, wherein the temperature of the oven is 70 ℃; introducing the hollow fiber membrane without the solvent into a circulating water tank with an ultrasonic device, and washing to remove sodium chloride, wherein the temperature of the water tank is 50 ℃, the ultrasonic power is 5kW, and the frequency is 15KHz; and drying the hollow fiber membrane subjected to desalting in a ventilation drying oven at the drying temperature of 50 ℃. And (3) performing secondary stretching on the dried hollow fiber membrane, wherein the primary stretching multiple is 1.2 times, the stretching temperature is 30 ℃, the secondary stretching multiple is 2 times, and the stretching temperature is 90 ℃. The equipment is arranged in the air draft device to collect the volatile solvent, so that the pollution of the solvent to the environment is prevented.
Winding and collecting the stretched hollow fiber membrane into a coil, wherein the outer diameter of the hollow fiber membrane is about 2.5mm, the inner diameter of the hollow fiber membrane is about 1.8mm, the average pore diameter of micropores obtained by a solvent removal thermal phase separation method is 0.5 mu m, the average pore diameter of micropores obtained by a desalting leaching method is 8 mu m, the porosity is about 70%, the volume ratio of prepared pores by solvent removal to prepared pores by desalting is about 5, and the pure water flux is 300L/m 2 H.bar, 88% of retention rate, 99% of antibacterial rate of escherichia coli and staphylococcus aureus and 25MPa of tensile strength.
Example 2
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 12wt%; sodium chloride particles: the average grain diameter is 10 mu m, and the content is 25wt%; decalin: the content was 58.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: content of 0.1wt%, ethylene-vinyl alcohol copolymer: the weight average molecular weight was 6500, the average particle diameter was 30 μm, and the content was 3% by weight.
The preparation method is the same as in example 1. Finally, the hollow fiber membrane with the outer diameter of about 2.4mm and the inner diameter of about 1.7mm was obtained, the mean pore diameter of micropores obtained by the solvent-removing thermal phase separation method was 0.55 μm, the mean pore diameter of micropores obtained by the salt-removing leaching method was 8 μm, the porosity was about 68%, the volume ratio of the solvent-removing pores to the salt-removing pores was about 5 2 H.bar, the retention rate is 86%, the antibacterial rates of escherichia coli and staphylococcus aureus are 99%, and the tensile strength is 24MPa.
Example 3
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 12 weight percent; sodium chloride particles: the average particle diameter is 10 μm, and the content is 22wt%; decalin: the content was 58.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: the content is 0.1wt%; ethylene-vinyl alcohol copolymer: the weight average molecular weight is 6500, the average particle diameter is 30 μm, and the content is 3wt%; carbon fiber: the content was 3wt%.
The preparation method is the same as that of example 1. Finally, the hollow fiber membrane with the outer diameter of about 2.5mm and the inner diameter of about 1.7mm was obtained, the mean pore diameter of micropores obtained by the solvent-removing thermal phase separation method was 0.50 μm, the mean pore diameter of micropores obtained by the salt-removing leaching method was 8 μm, the porosity was about 69%, the volume ratio of the solvent-removing pores to the salt-removing pores was about 5 2 H.bar, the retention rate is 87%, the antibacterial rates of escherichia coli and staphylococcus aureus are 99%, and the tensile strength is 29MPa.
Example 4
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 10wt%; sodium chloride particles: the average particle diameter is 50 μm, and the content is 20wt%; potassium sulfate particles: average particle diameter of 50 μm, content of 20wt%, decalin: the content was 42.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: the content is 0.1wt%; ethylene-vinyl alcohol copolymer: the weight average molecular weight is 6500, the average particle diameter is 30 μm, and the content is 3wt%; carbon fiber: the content was 3wt%.
The preparation method is the same as that of example 1. Finally, the hollow fiber membrane with the outer diameter of about 2.5mm and the inner diameter of about 1.7mm was obtained, the mean pore diameter of micropores obtained by the solvent-removing thermal phase separation method was 0.50 μm, the mean pore diameter of micropores obtained by the salt-removing leaching method was 35 μm, the porosity was about 70%, the volume ratio of the solvent-removing pores to the salt-removing pores was about 3 2 H.bar, the retention rate is 81%, the antibacterial rates of escherichia coli and staphylococcus aureus are 99%, and the tensile strength is 22MPa.
Example 5
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity-average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 11wt%; potassium chloride granules: the average grain diameter is 50 μm, and the content is 20wt%; sodium sulfate particles: the average grain diameter is 50 μm, and the content is 20wt%; decahydronaphthalene: the content was 42.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: the content is 0.05wt%; antioxidant 168: the content is 0.05wt%; polyethylene grafted maleic anhydride: the weight average molecular weight is 25000, the average particle size is 30 μm, and the content is 3wt%; carbon nanotube: the content was 2wt%.
The preparation method comprises the following steps:
adopting the process shown in FIG. 1, (1) stirring and mixing ultra-high molecular weight polyethylene, potassium chloride particles, sodium sulfate particles, decalin, an antioxidant, an antibacterial agent, polyethylene grafted maleic anhydride and carbon nano tubes in a stirring kettle 1 at normal temperature for 10min, wherein the rotating speed of a stirring paddle is 60rpm; introducing the uniformly mixed solution in the stirring kettle 1 into the stirring kettle 2, stirring and swelling for 10min to prepare the ultra-high molecular weight polyethylene gel, wherein the temperature is 160 ℃, and the rotating speed is 60rpm;
introducing the ultra-high molecular weight polyethylene gel in the stirring kettle 2 into a hopper for storage, wherein the temperature of the hopper is 140 ℃; the ultra-high molecular weight polyethylene jelly in the hopper is extruded by a double screw through a tubular single-hole spinneret, the extrusion temperature is 180-250 ℃, and the rotating speed of the screw is 200rpm. The diameter of the outer core of the spinning nozzle is 7mm, the diameter of the inner core is 5mm, air at 80 ℃ is introduced into the inner core, and the air flow is 2L/min;
(2) Cooling the protofilament extruded by the single-hole spinneret by a cooling air box, wherein the temperature of the air box is 110 ℃; then removing the solvent through a solvent removal oven, wherein the temperature of the oven is 70 ℃; introducing the hollow fiber membrane without the solvent into a circulating water tank with an ultrasonic device, and washing to remove the pore-forming agent, wherein the temperature of the water tank is 50 ℃, the ultrasonic power is 7kW, and the frequency is 18KHz; and drying the hollow fiber membrane subjected to desalting in a ventilation drying oven at the drying temperature of 50 ℃. And (3) performing secondary stretching on the dried hollow fiber membrane, wherein the primary stretching multiple is 1.2 times, the stretching temperature is 30 ℃, the secondary stretching multiple is 2 times, and the stretching temperature is 90 ℃. The equipment is arranged in the air draft device to collect the volatile solvent, so that the pollution of the solvent to the environment is prevented.
And winding and collecting the stretched hollow fiber membrane into a roll, wherein the outer diameter of the hollow fiber membrane is about 2.5mm, the inner diameter of the hollow fiber membrane is about 1.8mm, the average pore diameter of micropores obtained by a solvent removal thermal phase separation method is 0.35 mu m, the average pore diameter of micropores obtained by a desalting leaching method is 35 mu m, the porosity is about 73%, the volume ratio of solvent preparation pores to desalting preparation pores is about 3 2 H.bar, the retention rate is 85%, the antibacterial rates of escherichia coli and staphylococcus aureus are 99%, and the tensile strength is 23MPa.
Example 6
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight:
ultra-high molecular weight polyethylene: the viscosity-average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 11wt%; potassium chloride granules: the average grain diameter is 100 mu m, and the content is 20wt%; sodium sulfate particles: the average grain diameter is 100 μm, and the content is 20wt%; decahydronaphthalene: the content was 42.9wt%; silver ion-based antibacterial agent: the content is 1wt%; antioxidant 1010: the content is 0.05wt%; antioxidant 168: the content is 0.05wt%; polyethylene grafted maleic anhydride: weight average molecular weight 25000, average particle diameter30 μm, content 3wt%; carbon nanotube: the content was 2wt%. The preparation method is the same as in example 5. The finally obtained hollow fiber membrane had an outer diameter of about 2.5mm and an inner diameter of about 1.8mm, an average pore diameter of 0.35 μm in micropores obtained by the solvent-removing thermal phase separation method, an average pore diameter of 80 μm in micropores obtained by the desalting leaching method, a porosity of about 72%, a ratio of volume of solvent-prepared pores to volume of desalted pores of about 3 2 H.bar, the retention rate is 83 percent, the antibacterial rates of escherichia coli and staphylococcus aureus are 99 percent, and the tensile strength is 22MPa.
Comparative example 1
The ultra-high molecular weight polyethylene gel comprises the following raw materials in percentage by weight: ultra-high molecular weight polyethylene: the viscosity average molecular weight is 300 ten thousand, the average grain diameter is 100 mu m, and the content is 14wt%; decahydronaphthalene: the content was 79.9wt%; antioxidant 1010: the content is 0.1wt%; ethylene-vinyl alcohol copolymer: the weight average molecular weight is 6500, the average particle diameter is 30 μm, and the content is 3wt%; carbon fiber: the content was 3wt%, and the preparation method was the same as in example 1. The outer diameter of the finally obtained hollow fiber membrane is about 2.6mm, the inner diameter is about 1.8mm, the average pore diameter of micropores obtained by the solvent-removing thermal phase separation method is 0.55 mu m, and the porosity is about 80 percent. The pure water flux is 200L/m 2 H.bar, the retention rate is 86%, the antibacterial rates of escherichia coli and staphylococcus aureus are both 0%, and the tensile strength is 23MPa.
Claims (16)
1. An ultra-high molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution is prepared by the following steps:
(1) Mixing raw materials including ultra-high molecular weight polyethylene, a solvent, a water-soluble salt pore-foaming agent and an auxiliary additive to prepare ultra-high molecular weight polyethylene gel;
(2) The obtained ultra-high molecular weight polyethylene gel is subjected to at least the working procedures of extrusion, solidification, solvent removal, water-soluble salt pore-forming agent removal, drying and hot stretching to prepare a hollow fiber membrane with bimodal pore size distribution;
wherein, the porosity of the prepared hollow fiber membrane is 50-90%, the aperture of the micropore obtained by removing the solvent is 0.05-3 μm, the aperture of the micropore obtained by removing the pore-forming agent is 2-100 μm, and the volume ratio of the pore-forming agent to the pore-forming agent is 1-5.
2. The hollow fiber membrane of claim 1, wherein the ultra-high molecular weight polyethylene in step (1) is in the form of powdery particles having a viscosity average molecular weight of 150 to 500 ten thousand, a particle diameter of 5 to 500 μm, and a mass fraction in the ultra-high molecular weight polyethylene jelly of 5 to 40wt%.
3. The hollow fiber membrane of claim 2, wherein the particle size of the ultra-high molecular weight polyethylene in step (1) is 50 to 100 μm, and the mass fraction thereof in the ultra-high molecular weight polyethylene gel is 10 to 20wt%.
4. The hollow fiber membrane of claim 1, wherein the solvent in step (1) is one or more selected from the group consisting of decalin, tetralin, and xylene, and has a mass fraction of 40 to 80wt% in the ultra-high molecular weight polyethylene jelly.
5. The hollow fiber membrane of claim 4, wherein the solvent in step (1) is decalin.
6. The hollow fiber membrane of claim 1, wherein the water-soluble salt-type pore-forming agent in step (1) is one or more of sodium chloride, disodium hydrogen phosphate, sodium sulfate, potassium chloride and potassium sulfate, the average particle size is 5-100 μm, and the mass fraction in the ultra-high molecular weight polyethylene jelly is 10-50 wt%.
7. The hollow fiber membrane of claim 6, wherein the average particle size of the water-soluble salt-based pore-forming agent in step (1) is 10 to 50 μm.
8. The hollow fiber membrane of claim 1, wherein the auxiliary additive in step (1) is selected from the group consisting of: (1) The hydrophilic modifier is one or more selected from powdery ethylene-vinyl alcohol copolymer, polyethylene grafted maleic anhydride, polyvinylpyrrolidone and polyvinyl alcohol, the particle size is 5-100 mu m, and the mass fraction of the hydrophilic modifier in the ultra-high molecular weight polyethylene jelly is 0-5 wt%;
(2) The reinforcing agent is selected from one or more of carbon fiber, graphene, carbon nano tube, calcium carbonate and silicon dioxide, and the mass fraction of the reinforcing agent in the ultra-high molecular weight polyethylene jelly is 0-5 wt%;
(3) And the antioxidant is selected from one or more of antioxidant 168, antioxidant 1010, antioxidant 1076 and antioxidant 1098, and accounts for 0.1-1 wt% of the ultra-high molecular weight polyethylene gel.
9. The hollow fiber membrane of claim 8, wherein the hydrophilic modifier has a particle size of 30 to 50 μm.
10. The hollow fiber membrane of any one of claims 1 to 9, wherein an antibacterial agent is further added in step (1), and is selected from one or more of a silver ion antibacterial agent, a cobalt ion antibacterial agent, a zinc ion antibacterial agent and a copper ion antibacterial agent, and the mass fraction of the antibacterial agent in the ultra-high molecular weight polyethylene jelly is 0.05 to 2wt%.
11. The hollow fiber membrane of claim 10, wherein the antimicrobial agent is a silver ion based antimicrobial agent.
12. The hollow fiber membrane of any one of claims 1 to 9, wherein in step (1), the ultra-high molecular weight polyethylene jelly is prepared by uniformly mixing raw materials in a normal temperature mixing kettle and then introducing the mixture into a high temperature mixing kettle for swelling; the mixing temperature of the high-temperature mixing kettle is 120-160 ℃, the mixing time is 10-100 min, and the mixing rotating speed is 10-100 rpm.
13. The hollow fiber membrane of claim 1, wherein in step (2), the extrusion is in a twin-screw extruder and a tubular hollow spinneret, wherein the twin-screw extrusion temperature is 180-250 ℃ and the rotation speed is 60-400 rpm; and/or:
the inner core and the outer core of the tubular hollow spinneret are respectively a metal round tube with the diameter of 1-10 mm and a metal round tube with the diameter of 1.5-15 mm, and the number of holes of the spinneret is 1-12; and/or:
the curing process is carried out in an air circulation air box, and the temperature of the air box is 30-150 ℃; and/or:
the solvent removing process adopts a one-stage or multi-stage thermal oven, and the temperature of the oven is 40-80 ℃.
14. The hollow fiber membrane according to any one of claims 1 to 9 and 13, wherein the pore-forming agent removing step employs a circulating water tank to which ultrasonic waves are applied, the water temperature is 30 to 60 ℃, the ultrasonic wave power is 1 to 10kW, and the frequency is 10 to 25KHz; and/or:
the drying procedure adopts a one-stage or multi-stage drying oven, and the temperature of the drying oven is 40-80 ℃; and/or:
the hot stretching process adopts a multi-stage stretching roller, the roller temperature is 30-110 ℃, and the stretching multiplying power is 1-5 times.
15. The hollow fiber membrane according to claim 14, wherein the draw ratio is 2 to 3 times.
16. The hollow fiber membrane according to claim 1, wherein the hollow fiber membrane has an outer diameter of 0.3 to 10mm and an inner diameter of 0.1 to 9.5mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010941528.4A CN112316746B (en) | 2020-09-09 | 2020-09-09 | Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010941528.4A CN112316746B (en) | 2020-09-09 | 2020-09-09 | Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112316746A CN112316746A (en) | 2021-02-05 |
| CN112316746B true CN112316746B (en) | 2023-01-13 |
Family
ID=74303867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010941528.4A Active CN112316746B (en) | 2020-09-09 | 2020-09-09 | Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112316746B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113996274B (en) * | 2021-11-09 | 2023-10-13 | 万华化学集团股份有限公司 | Porous composite lithium adsorbent and preparation method thereof |
| KR102556301B1 (en) * | 2021-11-29 | 2023-07-18 | 주식회사 퓨어엔비텍 | Ultrahigh molecular weight polyethylene-based hollow fiber membrane and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001286740A (en) * | 2000-02-04 | 2001-10-16 | Kuraray Co Ltd | Hollow fiber membrane of ethylene/vinyl alcohol polymer |
| CN102743977A (en) * | 2012-06-18 | 2012-10-24 | 上海百菲特环保科技有限公司 | Preparation method of novel ultrahigh molecular weight polyethylene hollow fiber membrane |
| CN202666707U (en) * | 2011-06-07 | 2013-01-16 | 三菱丽阳株式会社 | Manufacturing device for porous hollow fiber membrane |
| JP2015167889A (en) * | 2014-03-05 | 2015-09-28 | 三菱樹脂株式会社 | Porous support for water treatment membrane, production method of porous support for water treatment membrane and water treatment membrane |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5762798A (en) * | 1991-04-12 | 1998-06-09 | Minntech Corporation | Hollow fiber membranes and method of manufacture |
| CN105363358B (en) * | 2015-12-14 | 2018-07-27 | 苏州君康医疗科技有限公司 | Polyether sulfone/polytetramethylene carbonate diol doughnut blend film and preparation method |
-
2020
- 2020-09-09 CN CN202010941528.4A patent/CN112316746B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001286740A (en) * | 2000-02-04 | 2001-10-16 | Kuraray Co Ltd | Hollow fiber membrane of ethylene/vinyl alcohol polymer |
| CN202666707U (en) * | 2011-06-07 | 2013-01-16 | 三菱丽阳株式会社 | Manufacturing device for porous hollow fiber membrane |
| CN102743977A (en) * | 2012-06-18 | 2012-10-24 | 上海百菲特环保科技有限公司 | Preparation method of novel ultrahigh molecular weight polyethylene hollow fiber membrane |
| JP2015167889A (en) * | 2014-03-05 | 2015-09-28 | 三菱樹脂株式会社 | Porous support for water treatment membrane, production method of porous support for water treatment membrane and water treatment membrane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112316746A (en) | 2021-02-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112316746B (en) | Ultrahigh molecular weight polyethylene hollow fiber membrane with bimodal pore size distribution and preparation method thereof | |
| CN111560140B (en) | Special organic electret master batch for melt-blown non-woven fabric for mask, preparation method of master batch and melt-blown non-woven fabric prepared from master batch | |
| DE69824276T2 (en) | METHOD FOR PRODUCING A HIGHLY PERMANENT MITROPOROUS POLYOLEFINIC FILM | |
| JPH01293102A (en) | Microporous hollow yarn membrane and its production | |
| CN102743977A (en) | Preparation method of novel ultrahigh molecular weight polyethylene hollow fiber membrane | |
| WO2005073302A1 (en) | Porous film and method for preparation thereof | |
| US11338253B2 (en) | Porous hollow fiber membrane, method for producing same, and water purification method | |
| MX2009012473A (en) | Process for the preparation of polymer yarns from ultra high molecular weight homopolymers or copolymers, polymer yarns, molded polymer parts, and the use of polymer yarns. | |
| CN106693729A (en) | Aromatic polyamide hollow fiber membrane, preparation method and application | |
| JPWO2010082437A1 (en) | Vinylidene fluoride resin hollow fiber porous membrane and method for producing the same | |
| JP2010046621A (en) | Separation refining method of inorganic nanoparticle | |
| KR101939328B1 (en) | Hollow Fiber Membrane Having Novel Structure and Method of Preparing the Same | |
| CN108977903B (en) | Preparation method of melt spinning of polyvinylidene fluoride hollow fiber filtering membrane | |
| CN114588792B (en) | Polyvinyl butyral blending reinforced polyvinylidene chloride ultrafiltration membrane and preparation method thereof | |
| CN110721598B (en) | Preparation method of high-flux porous membrane | |
| CN101890311B (en) | Method for preparing asymmetric polyvinylidene fluoride (PVDF) ultrafiltration membrane | |
| WO2021132399A1 (en) | Separation membrane and method for producing separation membrane | |
| JPH10316795A (en) | Production of porous film | |
| JP2012040521A (en) | Hollow fiber membrane and method for production of hollow fiber membrane | |
| JP3641321B2 (en) | Method for producing polyolefin microporous membrane | |
| JP2016097362A (en) | Porous hollow fiber membrane, method for producing porous hollow fiber membrane, and water purification method | |
| CN114806045B (en) | Modified master batch for preparing antibacterial polyvinylidene fluoride porous membrane and preparation method thereof | |
| CN114806044B (en) | Antibacterial polyvinylidene fluoride porous membrane and preparation method thereof | |
| JP7107429B2 (en) | Separation membrane and its manufacturing method | |
| KR20130076267A (en) | Manufacturing method of asymmetric pvdf membrane and asymmetric pvdf membrane with improved properties manufactured thereby |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |