CN107998903A - A kind of preparation method of polypropylene hollow fiber microporous membrane - Google Patents
A kind of preparation method of polypropylene hollow fiber microporous membrane Download PDFInfo
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- CN107998903A CN107998903A CN201610934885.1A CN201610934885A CN107998903A CN 107998903 A CN107998903 A CN 107998903A CN 201610934885 A CN201610934885 A CN 201610934885A CN 107998903 A CN107998903 A CN 107998903A
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- 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
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- 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
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- 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
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Abstract
The present invention relates to a kind of preparation method of polypropylene hollow fiber microporous membrane.For this method using polypropylene as raw material, high fatty amine ethylene oxide adduct is diluent, using thermally induced phase separation, obtains the polypropylene hollow fiber microporous membrane；The mixing ratio of polypropylene and high fatty amine ethylene oxide adduct is 20~35wt%：65~80wt%.This method also obtains environmentally friendly polypropylene hollow fiber microporous membrane by controlling Thermal inactive membrance casting condition to include extrusion temperature, cooling medium, cooling temperature, extraction and treatment conditions, its water contact angle is more than 120 °, porosity is more than 70%, with perforation, the surface being evenly distributed in spongiform microcellular structure section and micropore, the porosity of film is high, hydrophobicity is preferable, can be applied to membrane distillation and film degassing field.
Description
Technical field
The invention belongs to polymer material science field, is related to a kind of polymeric membrane for separation and preparation method thereof, more specifically
Ground, the present invention relates to a kind of preparation method of polypropylene hollow fiber microporous membrane.
Background technology
In recent years, with the shortage of water resource and increasingly stringent, sea water desalination and other high saliferous dirts of environmental regulation
The processing of water is also problem urgently to be resolved hurrily, wherein it is subject to people widely to study using membrane distillation desalination, what membrane distillation used
Film is usually the hydrophobic membrane being prepared by hydrophobic or hydrophobically modified polymeric material.
At present, the polymeric material of hydrophobic membrane is prepared usually with polypropylene (PP), polytetrafluoroethylene (PTFE) (PTFE), polyvinylidene fluoride
Based on alkene (PVDF).The surface energy of these types of material is all than relatively low.PTFE surface energies are minimum, have the hydrophobicity strong, excellent resistance to
, easily there is hole defect in preparation process in the performance of severe operating conditions, but material processing difficulties, and yield rate is low, film cost compared with
Height, and membrane module sealing is difficult.Compared with PTFE, pvdf membrane, PP has on material and processing cost and has great advantage, and prepares
Method is easy, and thermally induced phase separation (TIPS) is usually used in the method that the art prepares this microporous polypropylene membrane, fits
For under room temperature without suitable solvent be difficult to using phase separation film forming crystalline high polymer for example polypropylene, polyethylene,
Poly- (4-methyl-1-pentene) etc..
TIPS methods refer to using polymer and higher boiling, low volatility, low molecular weight solvent (as the dilution of polymer
Agent) at high temperature (fusing point for being generally greater than polymer), homogeneous phase solution is formed, then cooling down makes solution be separated,
Solvent extraction is removed again, the volume that solvent occupies becomes micropore, just becomes polymer microporous film.
The solvent that polymer is allowed to be formed homogeneous phase solution can be dissolved under the diluent, that is, high temperature used using TIPS legal systems film,
The structure of membrane product and performance have a major impact after phase separation of the diluent to polymer solution, film forming.It is required that diluent is in height
Temperature is lower to have good intermiscibility with polymer, and low volatility, heat endurance are good.Furthermore it is required that diluent has hypotoxicity, right
The negative effect of health and environment is smaller.But up to the present, there are reproduction and ring mostly for the solvent used in film-forming process
Border toxicity, detrimental effect is caused to health of human body and Environmental security, and strictly speaking, such film-forming process cannot be referred to as green
The clean process of color.Especially when enviromental protection law increasingly strictly gets up, environment amenable green solvent or low toxicity, low evil
The demand of solvent will be more and more stronger.
The outstanding advantage of TIPS methods is that the content of composition, polymer by varying diluent, cool down the conditions such as medium,
The adjustable microporous barrier of membrane pore structure can be made.And membrane porosity is high, flux is big, membrane aperture distribution is relatively uniform, has good
Mechanical strength.But if the film product control that this method obtains is improper, film surface is by with finer and close cortex.To table
The control of face structure is also the key problem in technology in TIPS method film-forming process.Since dilution diffusion is made between diluent and setting medium
With diluent is subject to transfer spreading in setting medium to act in casting solution and fiber radial symmetry gradient acts on, appearance
Face forms porous cortex, it is contemplated that smaller than the aperture of film inner surface, a degree of asymmetry is presented in membrane structure.Chinese patent
CN103007773B, CN103007776B, CN103007784B by select coagulating bath component species and concentration, solidification bath temperature
Residence time control in degree, coagulating bath series and coagulating bath at different levels, and it is applied to the preparation of polypropylene separation membrane, control
The pore structure and size of polypropylene separation membrane outer surface processed, it is intended to solve the problems, such as that polypropylene separation membrane outer surface cortex is fine and close.
In the technical field of microporous polypropylene membrane is prepared using TIPS methods, diluent rises during TIPS methods are film-made
Important function.Patent CN101862601A discloses a kind of polypropylene hollow fiber microporous membrane and preparation method thereof, using neighbour
Dibatyl phithalate, fatty amine, calcium stearate, isopropyl amine alcohol, methylbenzene propyl ester, vegetable oil or one kind or several in diphenyl ether
Kind combination is used as diluent.Patent CN201210434202.8 discloses a kind of preparation method of polypropylene hollow fiber hydrophobic membrane
And application, using the mixture of vegetable oil and phthalate as diluent.Patent CN1356410A discloses one kind
The method that thermally induced phase separation prepares microporous polypropylene membrane, using vegetable oil, atoleine, diphenyl ether, machine oil as diluent,
Adipic acid, benzoic acid are made homogeneous phase solution, polypropylene hollow fiber silk are spun into by spinning head, into water as auxiliary agent
Solidification, then by extraction, polypropylene hollow fiber membrane is made.Patent 00802940.7 and patent 00802939.3 also disclose
A kind of preparation method for being used for the overall asymmetric polyolefin hydrophobic membrane by thermal induction Liquid liquid Separation gas exchanges, using A and B
The mixed solvent system of two kinds of compound compositions, compound A is the Weak solvent of polymer, and compound B is the non-solvent of polymer.
Wherein for polypropylene, patent 00802940.7 use compound A for soybean oil, palm-kernel oil, dioctyl phthalate, N,
Double (2- ethoxys) tallow amines of N- or its mixture.Compound B is dibutyl phthalate, diethyl phthalate, sweet
Oily triacetate, castor oil or its mixture.Patent 00802939.3 is by N, N- double (2- ethoxys) tallow amine, phthalic acids
Dioctyl ester, soybean oil, palm-kernel oil or its mixture are used as compound A, by dibutyl phthalate, phthalic acid diethyl
Ester, triethylglycerides, castor oil or its mixture are used as polyacrylic compound B.
In conclusion the above patent use diluent be mostly the diluent system containing phthalic acid ester (such as
Dibutyl phthalate) and containing the irritating diluent system of diphenyl ether.This kind of diluent generally existing physiological-toxicity or
Person has intense stimulus smell, and studying tissue identification by international cancer has experimental animal or the mankind carcinogenic or infringement fertility energy
Power etc. influences.
The content of the invention
To overcome problems of the prior art, the present invention provides a kind of preparation of polypropylene hollow fiber microporous membrane
Method.Diluent used in the preparation method is non-toxic, and preparation process is environmental-friendly, the polypropylene hollow fiber being prepared
The surface that microporous barrier has perforation, is evenly distributed in spongiform microcellular structure section and micropore, surface separation layer micropore is adjustable,
And the porosity of film is high, hydrophobicity is preferable, can be applied to membrane distillation and film degassing field.
To achieve the above objectives, the present invention provides a kind of high fatty amine ethylene oxide adduct in thermally induced phase separation
The middle purposes as diluent；
The molecular structure of the high fatty amine ethylene oxide adduct has amphipathic：One end is hydrophilic radical amido,
Hydroxyl, amide groups, ehter bond etc. can also be used as polar hydrophilic group；The other end is hydrophobic grouping, nonpolar hydrocarbon chain, such as 8 carbon originals
Sub- above hydrocarbon chain；
The high fatty amine ethylene oxide adduct is polyoxyethylene alkyl amine, fatty acid amide or fatty alkanol amide.
It is described poly- when the high fatty amine ethylene oxide adduct is polyoxyethylene alkyl amine in such use
Ethylene oxide molecule of alkyl amine structural formula is：
Wherein, R is 8 carbon atom above hydrocarbon chains (fat-based), and p is 0-1；Q is 0-1；
It is that a kind of non-ionic surface is lived that the polyoxyethylene alkyl amine, which is also known as aliphatic amine polyoxyethylene ether (abbreviation amidogen ether),
Property agent, has one or two polyoxyethylene ether chain, a nitrogen-atoms and a long-chain fat base in its molecule；When fat primary amine with
Addition reaction occurs for ethylene oxide, generates the polyoxyethylene alkyl amine compound for having two polyoxyethylene ether chains in molecule；When secondary
When amine is with reacting ethylene oxide, due to there was only an active hydrogen, when it is with reacting ethylene oxide, generating in molecule has one
The polyoxyethylene alkyl amine compound of polyoxyethylene ether chain；
Since in the market major part fatty amine contains mixed alkyl chain, therefore the general aliphatic acid title using with its source
Corresponding trade name；These amine can react with the ethylene oxide of various dosages, with the increase of number of moles of ethylene oxide,
The enhancing of hydrophilic radical is represent, the hydrophily of its product also strengthens；The property of high fatty amine ethylene oxide adduct such as breast
The property changed, surface tension, dissolubility and cationic strength etc. also change.Also feelings can be distributed according to fatty amine atomic number of alkyl carbon
Condition distinguishes it；
When the polyoxyethylene alkyl amine is to have the compound of two polyoxyethylene ether chains in molecule, according to fat-based
Carbon chain lengths difference can be：(C14-C18) tallow double (2- ethoxys) amine, (C12-C14) double (2- ethoxys) amine of hydrogenation tallow,
(C14-C18) it is hydrogenated with tallow amine ethoxylate, (C14-C18) double (2- ethoxys) amine of double (2- ethoxys) amine or octadecyl；
When the polyoxyethylene alkyl amine is to have the compound of polyoxyethylene ether chain in molecule, concretely hydrogen
Change tallow amine polyoxyethylene ether；
When the high fatty amine ethylene oxide adduct is fatty acid amide, the fatty acid amide molecular formula is：(CH3
(CH2)m)2NCO(CH2)nCH3；
Such as m=1；N=10, the fatty acid amide are N, N- diethyl lauramides, molecular formula C16H33NO；
When the high fatty amine ethylene oxide adduct is fatty alkanol amide, the fatty alkanol amide molecular structural formula
For：
Wherein, R is 8 carbon atom above hydrocarbon chains (fat-based), p 1, q 1；
When R is CH3(CH2)10During-straight chained alkyl, the fatty alkanol amide is lauric acid diethyl amide.
Present invention also offers a kind of preparation method of polypropylene hollow fiber microporous membrane, include the following steps：
Using polypropylene as raw material, the high fatty amine ethylene oxide adduct is diluent, using thermally induced phase separation,
Obtain the polypropylene hollow fiber microporous membrane.
The polypropylene concretely acrylic resin.
In above-mentioned preparation method, the mixing ratio of polypropylene and high fatty amine ethylene oxide adduct for 20~
35wt%：65~80wt%.
In above-mentioned preparation method, the mixing ratio of polypropylene and high fatty amine ethylene oxide adduct is preferably 22.5~
27.5wt%：72.5~77.5wt%.
In above-mentioned preparation method, the polyoxyethylene alkyl amine is concretely：(C14-C18) tallow pair (2- ethoxys)
Amine, (C12-C14) hydrogenation tallow double (2- ethoxys) amine, (C14-C18) it is hydrogenated with tallow amine ethoxylate, (C14-C18) double (2- hydroxyl second
Base) amine, double (2- ethoxys) amine of octadecyl or hydrogenated tallow amine polyoxyethylene ether；
The fatty acid amide concretely N, N- diethyl lauramides；
The fatty alkanol amide concretely lauric acid diethyl amide.
In above-mentioned preparation method, the preparation method of the microporous polypropylene membrane includes the following steps：
Step A, is made casting solution after polypropylene is mixed with diluent；
Step B, casting solution is filtered；Concretely filtered by filter (such as 100 mesh stainless steel filter screens)；
Step C, is delivered to spinning head by the casting solution after filtering, then inner core liquid is incorporated into spinning head, with casting film
Liquid is expressed into cooling down in coagulating bath through spinning head together and, to curing, obtains polypropylene hollow fiber microporous membrane precursor；
Step D, extracts the diluent in polypropylene hollow fiber microporous membrane precursor with extractant, it is fine that hollow polypropylene is made
Tie up microporous barrier.
In above-mentioned preparation method, in step A, the temperature of casting solution is 175-200 DEG C；
And/or in step A, the casting solution is prepared according to the method included the following steps：Polypropylene and diluent are existed
Heated under vacuum, stand after being stirred, and is made by vacuum defoamation；
And/or in step B, the temperature of casting solution is 175-200 DEG C；
And/or in step C, the temperature of inner core liquid is 90-150 DEG C；
And/or in step C, inner core liquid for nitrogen, vegetable oil, high fatty amine ethylene oxide adduct or vegetable oil with
The mixture of high fatty amine ethylene oxide adduct；
And/or in step C, coagulating bath includes twin-stage coagulating bath；
And/or in step D, the polypropylene hollow fiber microporous membrane precursor used that extracts is to be wound by up- coiler
Polypropylene hollow fiber microporous membrane precursor afterwards；
And/or in step D, the extractant is alcohol；
And/or in step D, the time of the extraction is 3-48h；
And/or in step D, dry step is further included after the extraction.
In above-mentioned preparation method, in step A, the casting solution is prepared according to the method included the following steps：By poly- third
Alkene and diluent are added in the kettle with agitating device, 175~200 DEG C are heated to, at vacuum condition (such as pressure -0.095MPa)
Under, 0.5~12h is stirred, after stopping stirring, 0.5~12h of constant temperature standing and defoaming under vacuum condition (such as pressure -0.095MPa)；
And/or in step C, the vegetable oil in inner core liquid is soybean oil, the high fatty amine ethylene oxide in inner core liquid adds
It is polyoxyethylene alkyl amine into thing, such as (C14-C18) it is hydrogenated with tallow amine ethoxylate, (C14-C18) double (2- ethoxys) amine, octadecane
Double (2- ethoxys) amine of base or hydrogenated tallow amine polyoxyethylene ether；
And/or in step C, in the twin-stage coagulating bath, the temperature of first order coagulating bath is 100-150 DEG C, and cooling is situated between
Matter is air；
And/or in step C, in the twin-stage coagulating bath, the temperature of second level coagulating bath is 0-25 DEG C, and cooling medium is
The close or compatible system with diluent；
And/or it is ethanol or isopropanol when the extractant is alcohol in step D.
In the film-forming process that thermal induction causes phase separation, control process conditions have the temperature of casting solution, the temperature of spinning head
(temperature for being introduced into inner core liquid in spinning head), the temperature (outer surface for influencing film) of coagulating bath, the temperature of inner core liquid (influence film
Inner surface), and its cooling medium selection, the phase separation of these factors influence casting solutions, so influence film structure shape
State.
In above-mentioned preparation method, in the coagulating bath of the second level, cooling medium is air, vegetable oil, high fatty amine epoxy
The mixture of ethane additive product or vegetable oil and high fatty amine ethylene oxide adduct.
In above-mentioned preparation method, in the coagulating bath of the second level, the vegetable oil cooled down in medium is soybean oil；
The high fatty amine ethylene oxide adduct cooled down in medium is polyoxyethylene alkyl amine, such as (C14-C18) tallow pair
(2- ethoxys) amine, (C12-C14) hydrogenation tallow double (2- ethoxys) amine, (C14-C18) it is hydrogenated with tallow amine ethoxylate, (C14-C18)
Double (2- ethoxys) amine, preferably (C of double (2- ethoxys) amine or octadecyl14-C18) tallow double (2- ethoxys) amine, (C12-
C14) double (2- ethoxys) amine of hydrogenation tallow.
Beneficial effects of the present invention are as follows：
When preparing polypropylene hollow fiber membrane using TIPS in the prior art, diluent generally existing physiological-toxicity or tool
There is intense stimulus smell.When Chinese patent 103785303 prepares polypropylene hollow fiber hydrophobic membrane using thermally induced phase separation, adopt
Coagulating bath medium is used as by the use of the carcinogenic teratogenesis material for containing phthalic acid ester.The present invention is a kind of environmental-friendly by selecting
Diluent, polypropylene hollow fiber microporous membrane is prepared using thermal phase separation process, poly- by controlling the composition of casting solution to include
The concentration of compound, the composition and content of diluent, and Thermal inactive membrance casting condition include extrusion temperature, cool down medium, is cold
But temperature, extraction and treatment conditions obtain the preferably environmentally friendly polypropylene hollow fiber microporous membrane of hydrophobicity.The preparation side
Method solves diluent generally existing physiological-toxicity when preparing polypropylene hollow fiber membrane using TIPS in the prior art or has
The deficiency of intense stimulus smell, is particularly suitable for membrane distillation, film degassing field.The present invention is to prepare to gather using thermally induced phase separation
Propylene microcellular film provides a kind of brand-new method and approach, and the method for the present invention is easy, is suitable for commercial introduction application.Utilize
The water contact angle of polypropylene hollow fiber microporous membrane prepared by the method for the present invention is more than 120 °, and porosity is more than 70%, has and passes through
Surface that is logical, being evenly distributed in spongiform microcellular structure section and micropore, the porosity of film is high, and hydrophobicity is preferable.
Brief description of the drawings
The present invention has drawings described below：
Fig. 1 is the stereoscan photograph of film made from embodiment 1：(a) inner surface, (b) outer surface, (c) section.
Fig. 2 is the stereoscan photograph of film made from comparative example 1：(a) inner surface, (b) outer surface, (c) section.
Fig. 3 is the stereoscan photograph of film made from comparative example 2：(a) inner surface, (b) outer surface, (c) section.
Embodiment
To make the present invention easier to understand, below in conjunction with drawings and examples, the present invention will be described in detail, these realities
Apply example only serve it is illustrative, it is not limited to application range of the invention, unmentioned specific experiment side in the following example
Method, usually carries out according to normal experiment method.
Wt% in the following example is weight percentage.
Porosity test method in the following example：Tested using GB/T 21650.1-2008 mercury injection methods.
Water contact angle test method in the following example：Using contact angle tester, 1~180 ° of measurement range, is differentiated
Rate ± 0.1 °, using static sitting-drop methods, each fixed volume is the deionized water drop of 2 μ L, is dripped in film wire, taking the initial of calculating
Contact angle is the Contact-angle measurement value of hollow fiber film thread, and horizontal survey 6 times, calculates average value.
Membrane distillation permeant flux (J) test method in the following example：10 hollow fiber film threads are taken, make film forming group
Part, carries out vacuum membrane distillation test, condition is using 1wt% sodium chloride salts aqueous solution：80 DEG C of feeding temperature, vacuum transmembrane pressure
Power -0.09MPa, cross-flow filtration, flow velocity 0.62cm/s.The production water obtained in certain time is collected, is calculated by the following formula (1)
Membrane distillation permeant flux, measures 3 times, calculates average value.
Wherein W, A, and t represent production water weight, effective membrane area and interval production water time respectively.
Salt rejection rate (R) test method in the following example：Material liquid is tested using conductivity meter and produces the electrical conductivity of water,
Calculated by formula (2)
Wherein, Cp、CbRepresent the electrical conductivity of production water and material liquid.
Air penetrability (P, unit cm in the following example3/(cm2﹒ s ﹒ bar)) test method：Using bubble platen press membrane aperture point
Analyzer is tested.
Embodiment 1
A kind of polypropylene hollow fiber microporous membrane, porosity 75%, water contact angle are 125 °, and its preparation method is as follows：
(1) acrylic resin and 75wt% (C of 25wt% is added in the kettle with agitating device14-C18) tallow pair
(2- ethoxys) amine, is heated to 175 DEG C, under the conditions of pressure -0.095MPa, stirs 0.5h, after stopping stirring, -
Under 0.095MPa pressure, constant temperature standing and defoaming 0.5h, obtains casting solution；
(2) it is that 175 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 90 DEG C of temperature
Liquid nitrogen gas is incorporated into spinning head, is extruded together with casting solution through spinning head, and spinneret temperature is 150 DEG C；By 100 DEG C of air
Gap (i.e. first order coagulating bath), then obtains in polypropylene through 5 DEG C of air coolings (i.e. second level coagulating bath), cooling curing again
Hollow fiber microporous barrier precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 3 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
After tested, the film permeant flux for obtaining the vacuum membrane distillation of polypropylene hollow fiber microporous membrane is 25L/m2H, takes off
Salt rate is 99.95%, air penetrability 3.0cm3/(cm2﹒ s ﹒ bar), its stereoscan photograph as shown in Figure 1, Fig. 1 the result shows that：
Film section integrated symmetric, micropore are in the spongy pore structure continuously penetrated through, and film surfaces externally and internally is produced without dense layer surface.
Embodiment 2
A kind of polypropylene hollow fiber microporous membrane, porosity 73%, water contact angle are 130 °, and its preparation method is as follows：
(1) acrylic resin and 72.5wt% (C of 27.5wt% is added in the kettle with agitating device12-C14) plus
Double (2- ethoxys) amine of hydrogen tallow, are heated to 185 DEG C, under the conditions of pressure -0.095MPa, stir 1h, after stopping stirring, -
Under 0.095MPa pressure, constant temperature standing and defoaming 1h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 100 DEG C of temperature
Liquid soybean oil is incorporated into spinning head, is expressed into together with casting solution through spinning head in coagulating bath, and spinneret temperature is 145 DEG C；
It is 120 DEG C of the air gap (i.e. first order coagulating bath) through excess temperature, then cools down (i.e. the through the soybean oil that temperature is 10 DEG C again
Two level coagulating bath), cooling curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 6 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 30L/m2H, salt rejection rate 99.95%, air penetrability are
3.5cm3/(cm2﹒ s ﹒ bar).
Embodiment 3
A kind of polypropylene hollow fiber microporous membrane, porosity 71%, water contact angle are 132 °, and its preparation method is as follows：
(1) acrylic resin and 65wt% (C of 35wt% is added in the kettle with agitating device14-C18) hydrogenation ox
Fat amine ethoxylate, is heated to 200 DEG C, under the conditions of pressure -0.095MPa, stirs 2h, after stopping stirring, is pressed in -0.095MPa
Under power, constant temperature standing and defoaming 2h, obtains casting solution；
(2) it is that 200 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 110 DEG C of temperature
Liquid (soybean oil and (C14-C18) hydrogenation tallow amine ethoxylate, mass ratio 70:30) it is incorporated into spinning head, together with casting solution
Extruded through spinning head, spinneret temperature is 155 DEG C；It is 130 DEG C of the air gap (i.e. first order coagulating bath) through excess temperature, then
The soybean oil and (C for being again 10 DEG C through temperature14-C18) tallow amine ethoxylate mass ratio is hydrogenated with as 70:30 mixture cooling is (i.e.
Second level coagulating bath), cooling curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into isopropanol extraction 8 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 32L/m2H, salt rejection rate 99.98%, air penetrability are
4.0cm3/(cm2﹒ s ﹒ bar).
Embodiment 4
A kind of polypropylene hollow fiber microporous membrane, porosity 78%, water contact angle are 140 °, and its preparation method is as follows：
(1) acrylic resin and 77.5wt% (C of 22.5wt% is added in the kettle with agitating device14-C18) double
(2- ethoxys) amine, is heated to 185 DEG C, under the conditions of pressure -0.095MPa, 8h is stirred, after stopping stirring, in -0.095MPa
Under pressure, constant temperature standing and defoaming 8h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 120 DEG C of temperature
Liquid (C14-C18) double (2- ethoxys) amine are incorporated into spinning head, are extruded together with casting solution through spinning head, spinneret temperature is
160℃；It is 130 DEG C of the air gap (i.e. first order coagulating bath) through excess temperature, through temperature is again then 25 DEG C of (C14-C18)
Double (2- ethoxys) amine cool down (i.e. second level coagulating bath), and cooling curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 10 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 35L/m2H, salt rejection rate 99.98%, air penetrability are
4.2cm3/(cm2﹒ s ﹒ bar).
Embodiment 5
A kind of polypropylene hollow fiber microporous membrane, porosity 80%, water contact angle are 142 °, and its preparation method is as follows：
(1) acrylic resin of 20wt% and the octadecyl pair of 80wt% are added in the kettle with agitating device
(2- ethoxys) amine, is heated to 185 DEG C, under the conditions of pressure -0.095MPa, 10h is stirred, after stopping stirring, in -0.095MPa
Under pressure, constant temperature standing and defoaming 10h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 130 DEG C of temperature
Double (2- ethoxys) amine of liquid octadecyl are incorporated into spinning head, are extruded together with casting solution through spinning head, and spinneret temperature is
165℃；It is then double for 5 DEG C of octadecyl through temperature again through the air gap (i.e. first order coagulating bath) that excess temperature is 140 DEG C
(2- ethoxys) amine cools down (i.e. second level coagulating bath), and cooling curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into isopropanol extraction 12 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 38L/m2H, salt rejection rate 99.98%, air penetrability are
4.5cm3/(cm2﹒ s ﹒ bar).
Embodiment 6
A kind of polypropylene hollow fiber microporous membrane, porosity 80%, water contact angle are 142 °, and its preparation method is as follows：
(1) hydrogenated tallow amine for the acrylic resin and 80wt% for adding 20wt% in the kettle with agitating device gathers
Ethylene oxide ether, is heated to 185 DEG C, under the conditions of pressure -0.095MPa, 10h is stirred, after stopping stirring, in -0.095MPa pressure
Under, constant temperature standing and defoaming 10h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 140 DEG C of temperature
Liquid hydrogenated tallow amine polyoxyethylene ether is incorporated into spinning head, is extruded together with casting solution through spinning head, spinneret temperature 150
℃；Through the air gap (i.e. first order coagulating bath) that excess temperature is 140 DEG C, then gather again through the hydrogenated tallow amine that temperature is 5 DEG C
Ethylene oxide ether cools down (i.e. second level coagulating bath), and cooling curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 24 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 36L/m2H, salt rejection rate 99.98%, air penetrability are
4.6cm3/(cm2﹒ s ﹒ bar).
Embodiment 7
A kind of polypropylene hollow fiber microporous membrane, porosity 82%, water contact angle are 132 °, and its preparation method is as follows：
(1) acrylic resin of 20wt% and the laurate diethanol of 80wt% are added in the kettle with agitating device
Acid amides, is heated to 185 DEG C, under the conditions of pressure -0.095MPa, stirs 10h, after stopping stirring, under -0.095MPa pressure,
Constant temperature standing and defoaming 10h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 150 DEG C of temperature
Liquid nitrogen gas is incorporated into spinning head, is extruded together with casting solution through spinning head, and spinneret temperature is 150 DEG C；It is 150 through excess temperature
DEG C the air gap (i.e. first order coagulating bath), through temperature be again then 0 DEG C of air cooling (i.e. second level coagulating bath), cool down
Curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 48 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 38L/m2H, salt rejection rate 99.98%., air penetrability
For 4.8cm3/(cm2﹒ s ﹒ bar).
Embodiment 8
A kind of polypropylene hollow fiber microporous membrane, porosity 77%, water contact angle are 136 °, and its preparation method is as follows：
(1) acrylic resin of 22.5wt% and the N of 77.5wt%, N- diethyls are added in the kettle with agitating device
Base lauramide, is heated to 185 DEG C, under the conditions of pressure -0.095MPa, stirs 12h, after stopping stirring, is pressed in -0.095MPa
Under power, constant temperature standing and defoaming 12h, obtains casting solution；
(2) it is that 185 DEG C of casting solution is filtered through 100 mesh stainless steel filter screens by temperature, then by the inner core of 110 DEG C of temperature
Liquid nitrogen gas is incorporated into spinning head, is extruded together with casting solution through spinning head, and spinneret temperature is 150 DEG C；It is 120 through excess temperature
DEG C the air gap (i.e. first order coagulating bath), through temperature be again then 5 DEG C of air cooling (i.e. second level coagulating bath), cool down
Curing obtains polypropylene hollow fiber microporous membrane precursor；
(3) polypropylene hollow fiber microporous membrane precursor is wound by up- coiler, place into ethanol extraction 48 it is small when；
(4) polypropylene hollow fiber microporous membrane of the moistening obtained after extracting, it is naturally dry through air to be placed in fume hood room temperature
It is dry 12 it is small when；
(5) polypropylene hollow fiber microporous membrane is obtained after drying.
Its performance is tested, the film permeant flux of vacuum membrane distillation is 30L/m2H, salt rejection rate 99.98%, air penetrability are
4.0cm3/(cm2﹒ s ﹒ bar).
Comparative example 1
The preparation method of polypropylene hollow fiber microporous membrane is carried out according to embodiment 1, and difference is：In step (2)
Second level coagulating bath is used through 5 DEG C of water coolings.
As a result：After tested, the porosity for obtaining polypropylene hollow fiber microporous membrane is 56%, and water contact angle is 110 °, very
The film permeant flux of empty membrane distillation is 5L/m2H, salt rejection rate 99.95%, air penetrability 0.8cm3/(cm2﹒ s ﹒ bar)；It is swept
Electromicroscopic photograph is retouched as shown in Fig. 2, (b) display in Fig. 2, film outer surface is fine and close, is distributed without more micropore, this cause with it is real
Apply example 1 to compare, film permeant flux reduces, and air penetrability reduces.
The result shows that：In the case that other conditions are identical, second level coagulating bath is using air cooling with using water cooling phase
Than film outer surface produces the micropore being evenly distributed, and greatly improves film permeant flux and air penetrability.
Comparative example 2
The preparation method of polypropylene hollow fiber microporous membrane is carried out according to embodiment 1, and difference is：By embodiment 1
The step of (1) in diluent (C14-C18) double (2- ethoxys) amine of tallow replace with soya-bean oil and dibutyl phthalate by matter
Amount is than being 7：The mixed diluent of 3 compositions.
As a result：After tested, the membrane porosity of the polypropylene hollow fiber microporous membrane obtained is 60%, and water contact angle is
113 °, the film permeant flux of vacuum membrane distillation is 10L/m2H, salt rejection rate 99.95%, air penetrability 1.0cm3/(cm2﹒ s ﹒
Bar), its stereoscan photograph is as shown in figure 3, Fig. 3 is shown, although film surfaces externally and internally forms microcellular structure, film section is micro-
Pore structure not enough penetrates through, and has obvious lamination；And compared with the technical solution that embodiment 1 provides, phthalic acid two
Butyl ester has teratogenesis, unfriendly to environment.
The result shows that：In the case that other conditions are identical, diluent uses (C14-C18) double (2- ethoxys) amine of tallow with
Soya-bean oil is compared with the mixture of dibutyl phthalate, and membrane structure and performance are more excellent, and environmentally friendly.
The content not being described in detail in this specification belongs to the prior art known to professional and technical personnel in the field.
Claims (10)
1. purposes of the high fatty amine ethylene oxide adduct in thermally induced phase separation as diluent；
The high fatty amine ethylene oxide adduct is polyoxyethylene alkyl amine, fatty acid amide or fatty alkanol amide.
2. purposes as claimed in claim 1, it is characterised in that
When the high fatty amine ethylene oxide adduct is polyoxyethylene alkyl amine, the polyoxyethylene alkyl amine molecule knot
Structure formula is：
Wherein, R is 8 carbon atom above hydrocarbon chains, and p is 0-1；Q is 0-1；
When the high fatty amine ethylene oxide adduct is fatty acid amide, the fatty acid amide molecular formula is：(CH3
(CH2)m)2NCO(CH2)nCH3；
When the high fatty amine ethylene oxide adduct is fatty alkanol amide, the fatty alkanol amide molecular structural formula is：
Wherein, R is 8 carbon atom above hydrocarbon chains, p 1, q 1.
3. the preparation method of polypropylene hollow fiber microporous membrane, it is characterised in that include the following steps：
Using polypropylene as raw material, high fatty amine ethylene oxide adduct described in claim 1 or 2 is diluent, using heat
Phase separation method is caused, obtains the polypropylene hollow fiber microporous membrane.
4. preparation method as claimed in claim 3, it is characterised in that polypropylene and high fatty amine ethylene oxide adduct
Mixing ratio is 20~35wt%：65~80wt%.
5. preparation method as claimed in claim 3, it is characterised in that the polyoxyethylene alkyl amine is：(C14-C18) tallow pair
(2- ethoxys) amine, (C12-C14) hydrogenation tallow double (2- ethoxys) amine, (C14-C18) it is hydrogenated with tallow amine ethoxylate, (C14-C18)
Double (2- ethoxys) amine of double (2- ethoxys) amine, octadecyl or hydrogenated tallow amine polyoxyethylene ether；
The fatty acid amide is N, N- diethyl lauramides；
The fatty alkanol amide is lauric acid diethyl amide.
6. preparation method as claimed in claim 3, it is characterised in that the preparation method of the polypropylene hollow fiber microporous membrane
Include the following steps：
Step A, is made casting solution after polypropylene is mixed with diluent；
Step B, casting solution is filtered；
Step C, is delivered to spinning head by the casting solution after filtering, then inner core liquid is incorporated into spinning head, with casting solution one
Rise and be expressed into cooling down extremely curing in coagulating bath through spinning head, obtain polypropylene hollow fiber microporous membrane precursor；
Step D, extracts the diluent in polypropylene hollow fiber microporous membrane precursor with extractant, it is micro- that polypropylene hollow fiber is made
Pore membrane.
7. preparation method as claimed in claim 6, it is characterised in that in step A, the temperature of casting solution is 175-200 DEG C；
And/or in step A, the casting solution is prepared according to the method included the following steps：By polypropylene and diluent in vacuum
Under the conditions of heat, be stirred after stand, be made by vacuum defoamation；
And/or in step B, the temperature of casting solution is 175-200 DEG C；
And/or in step C, the temperature of inner core liquid is 90-150 DEG C；
And/or in step C, inner core liquid for nitrogen, vegetable oil, high fatty amine ethylene oxide adduct or vegetable oil with it is advanced
The mixture of fatty amine ethylene oxide adduct；
And/or in step C, coagulating bath includes twin-stage coagulating bath；
And/or in step D, the polypropylene hollow fiber microporous membrane precursor used that extracts is after up- coiler is wound
Polypropylene hollow fiber microporous membrane precursor；
And/or in step D, the extractant is alcohol；
And/or in step D, the time of the extraction is 3-48h；
And/or in step D, dry step is further included after the extraction.
8. preparation method as claimed in claim 7, it is characterised in that
In step A, the casting solution is prepared according to the method included the following steps：Polypropylene and diluent are added with stirring
In the kettle of device, 175~200 DEG C are heated to, under vacuum, stirs 0.5~12h, after stopping stirring, under vacuum
0.5~12h of constant temperature standing and defoaming；
And/or in step C, the vegetable oil in inner core liquid is soybean oil, the high fatty amine ethylene oxide adduct in inner core liquid
For polyoxyethylene alkyl amine；
And/or in step C, in the twin-stage coagulating bath, the temperature of first order coagulating bath is 100-150 DEG C, and cooling medium is
Air；
And/or in step C, in the twin-stage coagulating bath, the temperature of second level coagulating bath is 0-25 DEG C, cooling medium be with it is dilute
Release the close or compatible system of agent；
It is ethanol or isopropanol when the extractant is alcohol in step D.
9. preparation method as claimed in claim 8, it is characterised in that in the coagulating bath of the second level, cooling medium is air, plant
Oil, high fatty amine ethylene oxide adduct or the mixture of vegetable oil and high fatty amine ethylene oxide adduct.
10. preparation method as claimed in claim 9, it is characterised in that in the coagulating bath of the second level, cool down the vegetable oil in medium
For soybean oil；
The high fatty amine ethylene oxide adduct cooled down in medium is polyoxyethylene alkyl amine.
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