阅读说明：本技术 聚偏氟乙烯滤膜及其制备方法 (Kynoar filter membrane and preparation method thereof ) 是由 宋小飞 钟林 王镭 安婷婷 于 2018-05-21 设计创作，主要内容包括：本发明涉及膜材料领域,公开了一种聚偏氟乙烯滤膜及其制备方法。制备聚偏氟乙烯滤膜的方法包括将铸膜液涂覆于基板表面,再进行预蒸发、成膜和固化,其中,所述铸膜液含有质量比为100:(5-15):(10-25)的聚偏氟乙烯、聚酰胺和致孔剂。本发明还公开了上述方法制得的聚偏氟乙烯滤膜。通过上述技术方案,本发明获得了亲水性、截留率、热稳定性和化学稳定性均较优的聚偏氟乙烯滤膜。(The present invention relates to field of membrane material, a kind of Kynoar filter membrane and preparation method thereof is disclosed.The method for preparing Kynoar filter membrane includes that casting solution is coated on substrate surface, prevapourising, film forming and solidification are carried out again, wherein, it is 100:(5-15 that the casting solution, which contains mass ratio): Kynoar, polyamide and the pore-foaming agent of (10-25).The invention also discloses Kynoar filter membranes made from the above method.Through the above technical solutions, present invention obtains hydrophily, rejection, thermal stability and chemical stability preferably Kynoar filter membranes.)

1. a kind of method for preparing Kynoar filter membrane, this method includes that the casting solution after deaeration is coated on substrate surface, Prevapourising, film forming and solidification are carried out again, which is characterized in that it is 100:(5-15 that the casting solution, which contains mass ratio): (10-25's) Kynoar, polyamide and pore-foaming agent.

2. according to the method described in claim 1, wherein, the mass ratio between Kynoar, polyamide and pore-foaming agent is 100:(8-12):(22-25)。

3. method according to claim 1 or 2, wherein the number-average molecular weight of the Kynoar is 40-80 ten thousand；

And/or the polyamide is fatty polyamide and/or aromatic polyamide；

And/or the pore-foaming agent is polyvinylpyrrolidone and/or polyethylene glycol.

4. according to the method described in claim 3, wherein, the polyamide is poly；

And/or the polyethylene glycol is polyethylene glycol 200 and/or polyethylene glycol 400.

5. according to the method described in claim 1, wherein, the mass ratio between Kynoar and solvent in the casting solution For 100:(250-350)；

And/or the solvent in the casting solution be dimethylformamide, dimethyl acetamide and N-Methyl pyrrolidone in extremely Few one kind.

6. method according to claim 1 or 5, wherein the casting solution is made by the following method:

It at 50-80 DEG C, is dissolved in Kynoar in solvent, then the solution of acquisition is mixed with polyamide and pore-foaming agent.

7. according to the method described in claim 1, wherein, the casting solution carries out deaeration by the following method:

Casting solution is stood into 12-24h at 20-40 DEG C and/or is evacuated 3-5h under vacuum.

8. according to the method described in claim 1, wherein, the condition of prevapourising includes: that temperature is 20-35 DEG C, and relative humidity is 50-80%, time 20s-5min；

And/or the film forming carries out in a water bath, the condition of film forming includes: that temperature is 20-40 DEG C, time 3-10min.

9. according to the method described in claim 1, wherein, it is described be solidificated in the glycerol bath that glycerol content is 20-40wt% into Row, cured condition include: that temperature is 20-40 DEG C, time 5-20h.

10. Kynoar filter membrane made from method described in any one of -9 according to claim 1.

11. Kynoar filter membrane according to claim 10, wherein the average pore size of the Kynoar filter membrane is 0.01-0.04μm。

Technical field

The present invention relates to field of membrane material, and in particular, to Kynoar filter membrane and preparation method thereof.

Background technique

Membrane separation technique green high-efficient is widely used in Water warfare, chemical separating and field of biological pharmacy.Its In, ultrafiltration membrane can be effectively removed biomolecule, high molecular polymer and colloidal substance etc., and loading density is big, low energy consumption, It is easy to operate.Therefore, ultrafiltration membrane is widely used in the fields such as sewage treatment, chemical industry, biology, pharmacy.

Kynoar (PVDF) ultrafiltration membrane is because of its excellent thermal stability, chemical stability, heat radiation and excellent Mechanical performance is concerned, but PVDF ultrafiltration membrane surface C-F key abundant and c h bond keep its hydrophily poor.Hydrone is difficult to attached On pvdf membrane surface, cause water flux lower；On the other hand, organic matter is easily adsorbed on pvdf membrane surface, leads to membrane lifetime It reduces.Generally, the hydrophily of film can be improved by physics and chemical means.Method of modifying be broadly divided into membrane surface modification and It is membrane material modified.

Membrane surface modification is that polar group and hydrophilic molecule are introduced in the pvdf membrane surface and film inner hole prepared.Change Property method includes that surface covering, chemical modification and ion are modifies etc..It is membrane material modified including membrane material chemical modification and total Mixed modification.Wherein, blending and modifying is easy to operate, and hydrophilic radical is not easily to fall off, is convenient for large-scale promotion.In CN101703897A Polyether sulfone is blended with PVDF to improve the anti-contracility energy of film and hydrophily.By cellulose acetate, poly- in CN102716677A Methyl methacrylate is blended to improve the hydrophily and toughness of film.By hydrophilic nanoparticles and PVDF in CN101905123A It is blended to improve the hydrophily of film.But the ultrafiltration membrane that above method obtains is difficult to meet hydrophily, rejection, heat simultaneously surely The requirement of qualitative and chemical stability etc., use scope is limited, therefore, is improving hydrophilic while keeping as far as possible Or rejection, thermal stability and the chemical stability of raising film have a very important significance.

Summary of the invention

The purpose of the invention is to overcome the presence of the prior art to be difficult to ensure hydrophily, rejection, thermostabilization simultaneously The problem of property and chemical stability, provides a kind of PVDF filter membrane and preparation method thereof.

To achieve the goals above, the present invention provides a kind of method for preparing PVDF filter membrane, this method includes by casting film Liquid is coated on substrate surface, then carries out prevapourising, film forming and solidification, wherein it is 100:(5- that the casting solution, which contains mass ratio, 15): Kynoar, polyamide and the pore-foaming agent of (10-25).

The present invention also provides Kynoar filter membranes made from the above method.

Through the above technical solutions, present invention obtains hydrophily, rejection, thermal stability and chemical stability are more excellent Kynoar filter membrane, even if in casting solution do not include any surfactant in the case where.

Specific embodiment

The endpoint of disclosed range and any value are not limited to the accurate range or value herein, these ranges or Value should be understood as comprising the value close to these ranges or value.For numberical range, between the endpoint value of each range, respectively It can be combined with each other between the endpoint value of a range and individual point value, and individually between point value and obtain one or more New numberical range, these numberical ranges should be considered as specific open herein.

The method provided by the invention for preparing Kynoar filter membrane includes casting solution being coated on substrate surface, then carry out Prevapourising, film forming and solidification, which is characterized in that it is 100:(5-15 that the casting solution, which contains mass ratio): the poly- inclined fluorine of (10-25) Ethylene, polyamide and pore-foaming agent.

In the present invention, the mass ratio between Kynoar and polyamide is preferably 100:(8-12).

In the present invention, the mass ratio between Kynoar and pore-foaming agent is preferably 100:(22-25).

In the present invention, the Kynoar can be commonly used in the Kynoar for preparing filter membrane for this field, excellent Selection of land, the number-average molecular weight of the Kynoar are 40-80 ten thousand.

In the present invention, the polyamide can for this field common macromolecular main chain repetitive unit in contain amide groups The high polymer of group, but under preferable case, the polyamide is at least one of fatty polyamide and aromatic polyamides, more excellent It is selected as poly.The weight average molecular weight of poly can be 120-180 ten thousand.

In the present invention, the pore-foaming agent can common are for this field to help film and is formed in phase separation uniformly The substance of pore structure.Preferably, the pore-foaming agent is polyvinylpyrrolidone (PVP) and/or polyethylene glycol.Wherein, described Polyethylene glycol is preferably polyethylene glycol 200 (PEG-200) and/or polyethylene glycol 400 (PEG-400).

In the present invention, the concentration of Kynoar in casting solution is not required particularly, it is preferable that in the casting solution Solvent and Kynoar between mass ratio be (250-350): 100, more preferably (280-320): 100.It is further excellent Selection of land, the solvent in the casting solution are dimethylformamide (DMF), dimethyl acetamide (DMAc) and N-Methyl pyrrolidone At least one of (NMP).

The present invention obtains performance preferably filter membrane in the case where can not including any surfactant in casting solution, because This, the casting solution (spreads out without surfactant including various common carboxylates, sulfate, quaternary ammonium salt and polyethylene oxide Biology).

In the present invention, the casting solution can be obtained by various conventional modes, still, the present inventor's hair It is existing, Kynoar is first dissolved in a solvent, and adding polyamide and pore-foaming agent can make the filter membrane obtained have better property Can, it is therefore preferable that in the case of, the casting solution is made by the following method:

It at 50-80 DEG C, is dissolved in Kynoar in solvent, then the solution of acquisition is mixed with polyamide and pore-foaming agent It closes.Wherein, the order by merging of polyamide and pore-foaming agent is not required particularly, first solution can be made to mix with polyamide, First solution can be made to mix with pore-foaming agent, solution can also be mixed with polyamide and pore-foaming agent simultaneously.According to a kind of specific Embodiment, the method for preparing the casting solution include: to be dissolved in Kynoar in solvent at 50-80 DEG C, stir 1-5h To being completely dissolved, blend A is made；Polyamide is added in blend A, blend B is made in stirring 1-5h；At 50-80 DEG C, Pore-foaming agent is added in blend B, stirs 1-3h, obtains casting solution.

In the present invention, before coating, casting solution need to be subjected to deaeration, to remove bubble therein, consequently facilitating uniformly Coating.Deaeration can be carried out by the way of conventional, the mode of deaeration preferably includes: casting solution is stood 12- at 20-40 DEG C It is evacuated 3-5h for 24 hours and/or under vacuum.

In the present invention, it can be coated by the way of conventional, such as coated by scraper, knifing stick etc..Casting The thickness of film liquid coating is preferably 100-500 μm, and more preferably 150-300 μm.

In the present invention, because solvent volatilization will form cortex construction during prevapourising.The condition of prevapourising preferably includes: temperature It is 20-35 DEG C, more preferably 25-30 DEG C.The condition of prevapourising further preferably includes: that relative humidity is 50-80%, more preferably 60-70%.The condition of prevapourising further preferably include: the time be 20s-5min, more preferably 1-2min.

In the present invention, the film forming can carry out under conditions of routine, and such as mode of the film forming is to carry out water-bath.

Preferably, it is 20-40 DEG C that the condition of the water-bath (film forming), which includes: temperature,.It is further preferred that the water-bath The condition of (film forming) further include: time 3-10min.

In the present invention, the solidification can carry out under conditions of routine, and such as cured mode is to carry out glycerol bath.

Preferably, it is 20-40 DEG C that the condition of the glycerol bath (solidification), which includes: temperature,.It is further preferred that the glycerol Bathe the condition of (solidification) further include: time 5-20h.It is 20-40%'s that qualities of glycerin content, which can be used, in glycerol bath (solidification) Glycerine water solution.

The present invention also provides Kynoar filter membranes made from foregoing method.

According to the present invention, the average pore size of the Kynoar filter membrane is 0.01-0.04 μm, and pure water flux reaches 510L m^-2·h^-1(such as 440-510Lm^-2·h^-1), therefore can be used as ultrafiltration membrane use.

The present invention will be described in detail by way of examples below.In following embodiment, PVDF is Belgium Su Weigong The commercially available product that the trade mark is 6020 is taken charge of, number-average molecular weight is 800,000；PA is the poly- isophthalic two that Sheng Ou aramid fiber limited liability company provides Formyl m-phenylene diamine (MPD) industrial goods, weight average molecular weight are 1,400,000；PVP (K30), PEG-200 and PEG-400 are Chinese medicines group chemistry The commercially available product of reagent Co., Ltd.