CN1935341A - Polysulfone and polyethy lene base polymer blend membrane, and its preparing and use - Google Patents

Abstract

The present invention discloses a blending membrane made of polysulfone and polyvinyl polymer, including plate membrane and hollow fibre membrane. Its composition includes (by wt%) 5-25% of polysulfone, 1-10% of polyvinyl polymer and 1-20% of pore-forming agent. Said invention can be used as medical material, and can be used for making blood filtration, hemodialysis, ascites ultrafiltration, concentration and back transfusion and water treatment. Besides, said invention also provides its preparation method and concrete steps.

Description

A blend film of polysulfone and polyvinyl polymer, its preparation method and application

technical field

The invention relates to a blended membrane, its preparation method and application, in particular to a blended membrane of polysulfone and polyvinyl polymer, its preparation method and its application.

Background technique

The existence of the sulfone group in the polysulfone molecule makes it have a much larger polar sulfone group dipole moment than that of general polar solvents, so polysulfone has good stability to general chemical reagents; since the sulfur atom on the sulfone group is at the highest Oxidation state, so polysulfone has strong oxidation resistance and acid and alkali resistance; at the same time, because diphenyl sulfone is an aromatic compound, it is in a highly conjugated state, so its chemical bond can absorb a large amount of radiant heat without making the main bond And the branch bond is broken, which makes polysulfone have better heat resistance; and because of the existence of ether group and isopropylidene group, polysulfone has better hydrolysis resistance; in addition, due to the total The steric position of the diphenylsulfone group in the choke system is very stable, so it is difficult for chain scission and crosslinking to occur, which enables polysulfone to maintain high strength at high temperatures, and the creep value under continuous load is small ( 100°C, under 21MPa load, the creep value after 1000h is only 1.5%). The good physical, chemical and mechanical properties of polysulfone make it widely used in machinery, electronics, instrumentation and other fields to make parts with corrosion resistance, high strength and high dimensional stability.

The good stability of polysulfone in acid-base, hot water and steam is also an important condition for selecting it as an ultrafiltration membrane material. Taking advantage of the good processability of polysulfone solution, polysulfone can be made into hollow fiber ultrafiltration membranes in addition to tube-type, flat-plate and roll-type ultrafiltration membranes. Because the diameter of the hollow fiber membrane is small, it does not require any supporting structure after being assembled into a bundle, so the ultrafiltration membrane filter assembled with it has a simple structure and low equipment cost, and the membrane area provided per unit volume in the equipment is , much larger than equipment made of other forms of membranes. According to the specific surface area (ratio of membrane area to equipment volume), the specific surface area of hollow fiber membrane equipment is about 30 times that of tubular membrane equipment and 20 times that of flat membrane equipment. times, 15 times that of roll-type membrane equipment, it can be seen that the working efficiency of hollow fiber membrane equipment with the same volume is much higher than that of other forms of membrane equipment.

The use of polysulfone as a membrane material has been reported in many literatures and patents. Ling Ailian and others reported the polyacrylonitrile-polysulfone blend ultrafiltration membrane and its preparation method (application number: 94104420.3); Jiang Chengzhang et al. reported the preparation of high permeability polysulfone hollow fiber ultrafiltration membrane (application number: 91106007.3), Its preparation process includes the casting solution of polysulfone-solvent-non-solvent-salt-surfactant five-component system configuration and dry spray-wet spinning spinning technology; Kawada Ichiro et al. reported polysulfone hollow fiber membrane and its Preparation method (application number: 93106369.8), which is composed of polysulfone and a small amount of polyvinylpyrrolidone; Nan Zhenhua et al. reported a modified polysulfone ultrafiltration membrane and its preparation and application (application number: 94112724.9) , is obtained by modifying polysulfone through acylation-amination or chloromethylation-amination. At present, most of them use polysulfone alone as the membrane material, and the prepared membrane has defects such as low strength, low pressure resistance, and poor biocompatibility.

Contents of the invention

The technical problem to be solved by the present invention is to provide a blend film of polysulfone and polyvinyl polymer, its preparation method and application, so as to make up for the deficiencies or defects of the prior art and meet the needs of production or life.

In order to solve the above technical problems, one of the technical solutions adopted in the present invention is: a blended membrane of polysulfone and polyvinyl polymers, including flat membranes and hollow fiber membranes, the components of which are polysulfone, polyethylene Base polymer and porogen, the weight ratio of the three components is 5-25:1-10:1-20; the polyvinyl polymer is polyacrylonitrile, polyvinyl chloride, polyvinylidene fluoride Ethylene or polyvinyl alcohol; the porogen is one of polyvinylpyrrolidone, polyethylene glycol, lithium chloride or sodium nitrate or a mixture thereof.

As a preferred technical solution: the flat membrane thickness is 50-300 μm, the average pore diameter is 0.02-0.05 μm, the pure water flux is 50-400L/m ² .h (0.1MPa), and the bovine serum albumin rejection rate is 80 -95%, withstand pressure 0.1-0.8MPa.

The hollow fiber membrane has a thickness of 40-300 μm, an inner diameter of 200-500 μm, a flux of pure water of 50-500 L/m ² .h (0.1 MPa), a rejection rate of bovine serum albumin of 90-100%, and is resistant to Pressure 0.1-0.8MPa.

In order to solve the above-mentioned technical problems, the second technical solution adopted in the present invention is: a method for preparing a blended membrane, comprising the following steps:

(1) Preparation of casting solution: at a temperature of 40-80°C, polysulfone, polyvinyl polymer, porogen and Solvents are mixed, and the casting solution is made by swelling and dissolving, and the casting solution is filtered and defoamed for use;

(2) Preparation of flat film by flat plate method: form a uniform liquid layer on a clean glass plate with the prepared film casting liquid, pre-evaporate for 0-80 minutes, immerse in a coagulation bath to form a film, and the primary film is washed with water and preserved. After hole treatment and drying, a flat membrane is made, and the coagulation bath is an aqueous solution containing 0-60% by weight of solvent or alcohol; dry-wet spinning hollow fiber membrane: the casting solution is metered by a metering pump After entering the concentric tube spinneret and extruding into the air, after a 40-350mm dry spinning process, it enters an aqueous solution with a solvent content of 0-10% and a coagulation bath with a temperature of 20-60°C to form a primary film. After washing, pore-preserving treatment and drying, the hollow fiber membrane is made, wherein the filling fluid pressure in the spinneret cavity is 1.5×10 ^-3 MPa-5.5×10 ^-3 MPa, and the filling fluid is 0-10% solvent , an aqueous solution of ethanol or glycerol; the pore-preserving treatment is to use a pore-preserving agent to carry out pore-preserving treatment.

As a preferred technical solution: the solvent is one or more of dimethylsulfoxide, dimethylformamide, dimethylacetamide or N-methyl-2-pyridinone.

The pore-preserving agent for the pore-preserving treatment is an aqueous solution of monohydric alcohol or polyhydric alcohol, which can be used alone or in combination, the concentration of the pore-preserving agent is 10%-50%, and the pore-preserving treatment time is 3-9 hours.

The monoalcohol or polyhydric alcohol is methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, isoamyl alcohol, ethylene glycol or glycerol.

The rotating speed of the metering pump is 6-25r/min, and the spinning pressure is 0.3-0.7MPa.

The primary film is stretched four times, washed three times, wound at a speed of 20-50m/min, and subjected to pore-preserving treatment.

In order to solve the above technical problems, the third technical solution adopted by the present invention is: the use of a blended membrane, which can be applied to hemofiltration, hemodialysis, ascites ultrafiltration concentration reinfusion and water treatment.

The preparation of the polysulfone and polyvinyl polymer blend membrane of the present invention is based on the following principle: in the method of the present invention, in addition to using polysulfone as the main membrane material, polyvinyl polymer is also used for blending with it . By using the compatibility of the two polymers, the phase domain size of the two polymers in the solution is controlled, thereby finally controlling the size of the micropores after the film is formed.

The beneficial effects of the present invention are:

(1) The preparation method of the membrane in the present invention provides core technologies for the manufacture of hemofilters, hemodialyzers, ascites ultrafiltration concentration return devices and water treatment filters.

(2) As a medical material, the blood compatibility of the present invention is good.

(3) The defect of the single-component polymer film is improved, the film material of the present invention has high strength, and the film is not easily broken.

(4) In the present invention, under the condition that the water flux is higher, the protein retention rate is also higher.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples.

Example 1

According to the following components and mass percentages: polysulfone 12%; polyvinylidene fluoride 2%; polyvinylpyrrolidone 5%; polyethylene glycol 10%; dimethylacetamide 71%. Put the above-mentioned raw materials into the dissolver, and at 40°C, swell and dissolve to make a casting solution. The casting solution is filtered and defoamed before use. Keep the clean glass plate and scraper at the same temperature as the casting solution. Pour the casting solution on one end of the glass plate and use a scraper to form a uniform liquid film. After pre-evaporating for 30 minutes, immerse it in a water bath. After the raw film floats up from the glass plate, it is fully washed and soaked in distilled water to remove the solvent, treated with 10% pore-preserving agent methanol for 3 hours, and dried at low temperature after pore-preserving treatment. The water flux of the membrane is 260L/m2.h, and the rejection rate of bovine serum albumin is 80%. The membrane can be applied to hemofiltration, hemodialysis, ascites ultrafiltration concentration filtration, water treatment and the like.

Example 2

The casting solution in Example 1 is spun into a hollow fiber membrane through a concentric tubular spinneret. The membrane forming process is as follows: metering pump specification 0.40ml/r, pump speed 13r/min, air section length 200mm, internal and external solidification The bath is water at a temperature of 60° C., and the spinning speed is 30 m/min. After the primary film is formed, it can be assembled after being washed with water and pore-preserving treatment, and then dried at low temperature. Among them, the pressure of the filling fluid in the inner cavity of the spinneret is 1.5×10 ^-3 MPa, the filling fluid is 5% ethanol aqueous solution, the water flux of the membrane is 410L/m ² .h, and the rejection rate of bovine serum albumin is 95%. The membrane can be applied to hemofiltration, hemodialysis, ascites ultrafiltration concentration filtration, water treatment and the like.

Example 3

According to the following components and ingredients: 15% polysulfone; 3% polyvinylidene fluoride; 5% polyvinylpyrrolidone; 5% polyethylene glycol; 72% dimethylacetamide. The above raw materials were dissolved to form a membrane according to the method of Example 1. The water flux of the membrane was 200 L/m ² .h, and the rejection rate of bovine serum albumin was 87%.

Example 4

The casting solution in Example 1 was spun into a hollow fiber membrane through a concentric tubular spinneret, and the membrane forming process was carried out according to the method in Example 2. The water flux of the membrane is 350L/m ² .h, and the rejection rate of bovine serum albumin is 98%.

Claims (10)

1, the blend film of a kind of polysulfones and vinylic polymers comprises flat sheet membrane and hollow-fibre membrane, and its component is polysulfones, vinylic polymers and pore-foaming agent, and the weight ratio of three kinds of components is 5-25: 1-10: 1-20; Described vinylic polymers is polyacrylonitrile, polyvinyl chloride, Kynoar or polyvinyl alcohol; Described pore-foaming agent is a kind of or its mixture in polyvinylpyrrolidone, polyethylene glycol, lithium chloride or the sodium nitrate.

2, blend film according to claim 1 is characterized in that, described flat sheet membrane thickness is 50-300 μ m, and average pore size is 0.02-0.05 μ m, and pure water flux is 50-400L/m ².h (0.1MPa), the bovine serum albumin rejection is 80-95%, proof pressure 0.1-0.8MPa.

3, blend film according to claim 1 is characterized in that, the thickness of described hollow-fibre membrane is 40-300 μ m, and internal diameter is 200-500 μ m, and pure water flux is 50-500L/m ².h (0.1MPa), the bovine serum albumin rejection is 90-100%, proof pressure 0.1-0.8MPa.

4, a kind of preparation method of blend film as claimed in claim 1 is characterized in that, comprises the steps:

(1) preparation casting solution: under 40～80 ℃ of temperature, be polysulfones, vinylic polymers, pore-foaming agent and the solvent of 5-25: 1-10: 1-20: 60-90, make casting solution through swelling and dissolving with weight ratio, casting solution after filtration, stand-by after the deaeration;

(2) flat band method prepares flat sheet membrane: the casting solution of preparation is formed the layer of even liquid layer on the glass plate of cleaning, prevapourising 0-80 minute, be immersed in film forming in the coagulating bath, nascent film through washing, protect that the hole is handled and drying after make flat sheet membrane, described coagulating bath is that to contain percentage by weight be the solvent of 0-60% or the aqueous solution of alcohols; Do-wet method spinning hollow-fibre membrane: casting solution is entered concentric circles tubular type spinning head clamp-on in the air after the measuring pump metering, after the dry-spinning path of 40-350mm, enter the coagulating bath that the aqueous solution that solvent is 0-10% and temperature be 20-60 ℃ and form nascent film, nascent film is made hollow-fibre membrane through washing, guarantor hole after handling and drying, wherein, spinning head inner chamber filling liquid pressure is 1.5 * 10 ^-3MPa-5.5 * 10 ^-3MPa, filling liquid is the aqueous solution of solvent, ethanol or the glycerine of 0-10%; Handle in described guarantor hole is to protect the hole processing with protecting the hole agent.

5, preparation method according to claim 4 is characterized in that, described solvent is one or more in dimethyl sulfoxide (DMSO), dimethyl formamide, dimethylacetylamide or N-methyl-2-pyridine alkane ketone.

6, preparation method according to claim 4 is characterized in that, the guarantor hole agent that usefulness is handled in described guarantor hole is the aqueous solution of monohydric alcohol or polyalcohol, uses separately or multiple mixing use, and protecting the hole agent concentration is 10%-50%, and protecting the hole processing time is 3-9 hour.

According to claim 4 or 6 described preparation methods, it is characterized in that 7, described monohydric alcohol or polyalcohol are methyl alcohol, ethanol, normal propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, isoamyl alcohol, ethylene glycol or glycerine.

8, preparation method according to claim 4 is characterized in that, the rotating speed of described measuring pump is 6-25r/min, and spinning pressure is 0.3-0.7MPa.

9, preparation method according to claim 4 is characterized in that, described nascent film stretches through four roads, the washing of three roads, reels with the speed of 20-50m/min, and protects the hole and handle.

10, a kind of purposes of blend film as claimed in claim 1 is characterized in that, can be applicable to blood filtering, haemodialysis, the concentrated feedback of ascites ultra-filtration and water treatment aspect.