CN104607071A - Polyvinylidene fluoride hydrophilic membrane preparation method - Google Patents

Abstract

A polyvinylidene fluoride hydrophilic membrane preparation method belongs to the preparation field of membrane material. The invention provides the hydrophilic polyvinylidene fluoride hydrophilic membrane. According to the invention, a strong oxidizing property of ozone is utilized for treating polyvinylidene fluoride dissolved in N-methyl pyrrolidone by introducing peroxide groups; hydrophilic polyethylene glycol methacrylate (PEGMA) is prepared through graft polymerization adopting thermal initiation; and PVDF membrane with the hydrophilic property is prepared by a phase transmission method. Preparing microcapsules by the method does not need special cultivation methods and yeast used in the method has no biological activity. The preparation method can prepare the polyvinylidene fluoride separation membrane material with the hydrophilic property and uniform pore size distribution and has a good application prospect.

Description

A kind of Kynoar hydrophilic film preparation method

Technical field

The invention belongs to membrane material preparation field.

Background technology

Kynoar (PVDF) is a kind of Crystalline plastics, it has outstanding chemical stability, radiation resistance and heat resistance, and some strong polar organic solvent can be dissolved at a lower temperature, being easy to use phase inversion masking, is a kind of membrane material of function admirable.In membrane separation technique, cause the interest that people are very large, be successfully applied to the fields such as chemical industry, electronics, weaving, food, biochemistry.But the surface energy of PVDF is very low, be the material that a kind of hydrophobicity is very strong, and the hydrophobicity of PVDF limit its application in aqueous phase separation.In separation process, be easily subject to adsorption fouling and cause flux depression, when separating oil/aqueous systems (especially proteinaceous solution), adsorption fouling is serious, flux decline is very fast, reduce the service life of film, add operating cost, constrain its application in UF membrane field, therefore the hydrophilicity-imparting treatment of pvdf membrane seems particularly important.Its antifouling property can be improved by the surface hydrophilicity improving pvdf membrane, expand its range of application. and the hydrophilic modification of polymer film can be divided into chemic modified method and physical modified method two kinds.Wherein chemic modified method has surface oxidation method, plasma Inducing Graft modification method, light-initiated graft modification, surfactant method etc.; Physical modified method has plasma treatment, blending method, high-energy radiation method etc.Although these method of modifying can the hydrophily of increase film in various degree, effectively reduce fouling membrane.But above-mentioned method of modifying is all shaping rear to film modifying surface at film, the structural form of film and chemical property are subject to modification impact and change, and as membrane structure and size distribution change, membrane material intensity reduces, and the shortcoming such as poor stability.

Summary of the invention

The object of this invention is to provide one and overcome above-mentioned defect, there is hydrophilic Kynoar hydrophilic film preparation method.

The present invention is achieved by the following technical programs: a kind of Kynoar hydrophilic film preparation method, comprises the ozone pretreatment of Kynoar, the reaction of Kynoar grafted methacrylic acid macrogol ester and preparation three step of polyvinylidene fluoride separation membrane;

The ozone pre-treatment step of described Kynoar is, it is the solution of 80g/L that Kynoar (PVDF) is dissolved in configuration concentration in 1-METHYLPYRROLIDONE (NMP), at 25 DEG C by O ₃/ O ₂mist continue through this solution, the oxygen flow passed into is 300L/h, and the ozone concentration of generation is 0.06g/L, and ozone treatment time is set as 10min, and process terminates post-consumer polymer solution and cools in ice-water bath;

Described Kynoar grafted methacrylic acid macrogol ester reactions steps is, Kynoar (PVDF) solution after ozone treatment and methacrylic acid macrogol ester (PEGMA) being added has in the there-necked flask of condenser pipe, PEGMA concentration adjustment O.1 ~ O.3g/mL between, the volume of reaction solution is finally adjusted to 50mL, solution under agitation, pass into nitrogen exhaust 30min, hot Inducing Graft Polymerization at 80 DEG C, maintaining nitrogen purge protection in the course of the polymerization process, after reaction terminates, cool in ice-water bath, be precipitated out in excessive absolute ethyl alcohol, by the PVDF-g-PEG-MA that is settled out cyclic washing twice in 200mL absolute ethyl alcohol, finally wash in deionized water. the PVDF-g-PEGMA after washing is put into vacuum drying chamber inner drying,

Described polyvinylidene fluoride separation membrane preparation process is, PVDF-g-PEGMA is dissolved in NMP, mass fraction is 15%, after standing and defoaming, be coated on bright and clean glass plate with scraper under room temperature, place certain hour in atmosphere, make certain solvent volatilization. then immerse in deionized water, freezing film, film is dry in vacuum drying oven, obtain final finished.

The present invention has following beneficial effect:

The method of the invention utilizes the strong oxidizing property of ozone to produce peroxide bridge on PVDF, and by hot Inducing Graft Polymerization hydrophily PEGMA, the functional modification realizing PVDF obtains the polyvinylidene fluoride separation membrane material with water-wet behavior, even aperture distribution.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention will be further described.

Specific embodiment: preparation process of the present invention comprises the ozone pretreatment of Kynoar, the reaction of Kynoar grafted methacrylic acid macrogol ester and preparation three step of polyvinylidene fluoride separation membrane;

The ozone pre-treatment step of described Kynoar is, it is the solution of 80g/L that Kynoar (PVDF) is dissolved in configuration concentration in 1-METHYLPYRROLIDONE (NMP), at 25 DEG C by O ₃/ O ₂mist continue through this solution, the oxygen flow passed into is 300L/h, and the ozone concentration of generation is 0.06g/L, and ozone treatment time is set as 10min, and process terminates post-consumer polymer solution and cools in ice-water bath;

Described Kynoar grafted methacrylic acid macrogol ester reactions steps is, Kynoar (PVDF) solution after ozone treatment and methacrylic acid macrogol ester (PEGMA) being added has in the there-necked flask of condenser pipe, PEGMA concentration adjustment O.1 ~ O.3g/mL between, the volume of reaction solution is finally adjusted to 50mL, solution under agitation, pass into nitrogen exhaust 30min, hot Inducing Graft Polymerization at 80 DEG C, maintaining nitrogen purge protection in the course of the polymerization process, after reaction terminates, cool in ice-water bath, be precipitated out in excessive absolute ethyl alcohol, by the PVDF-g-PEG-MA that is settled out cyclic washing twice in 200mL absolute ethyl alcohol, finally wash in deionized water. the PVDF-g-PEGMA after washing is put into vacuum drying chamber inner drying,

Described polyvinylidene fluoride separation membrane preparation process is, PVDF-g-PEGMA is dissolved in NMP, mass fraction is 15%, after standing and defoaming, be coated on bright and clean glass plate with scraper under room temperature, place certain hour in atmosphere, make certain solvent volatilization. then immerse in deionized water, freezing film, film is dry in vacuum drying oven, obtain final finished.

The stuctures and properties of the modified Kynoar of grafting is characterized, infrared spectrum is presented at the characteristic absorption peak that PEGMA appears in l734cm-1 place, show that the pvdf membrane contact angle in successful grafting after PEGMA. grafting is reduced to 42 °, show good hydrophily.

Above content is the further description done the present invention in conjunction with concrete embodiment, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, some simple deduction or replace can also be made, all should be considered as belonging to protection scope of the present invention.

Claims (1)

1. a Kynoar hydrophilic film preparation method, is characterized in that: comprise the ozone pretreatment of Kynoar, the reaction of Kynoar grafted methacrylic acid macrogol ester and preparation three step of polyvinylidene fluoride separation membrane;

The ozone pre-treatment step of described Kynoar is, it is the solution of 80g/L that Kynoar (PVDF) is dissolved in configuration concentration in 1-METHYLPYRROLIDONE (NMP), at 25 DEG C by O ₃/ O ₂mist continue through this solution, the oxygen flow passed into is 300L/h, and the ozone concentration of generation is 0.06g/L, and ozone treatment time is set as 10min, and process terminates post-consumer polymer solution and cools in ice-water bath;

Described Kynoar grafted methacrylic acid macrogol ester reactions steps is, Kynoar (PVDF) solution after ozone treatment and methacrylic acid macrogol ester (PEGMA) being added has in the there-necked flask of condenser pipe, PEGMA concentration adjustment O.1 ~ O.3g/mL between, the volume of reaction solution is finally adjusted to 50mL, solution under agitation, pass into nitrogen exhaust 30min, hot Inducing Graft Polymerization at 80 DEG C, maintaining nitrogen purge protection in the course of the polymerization process, after reaction terminates, cool in ice-water bath, be precipitated out in excessive absolute ethyl alcohol, by the PVDF-g-PEG-MA that is settled out cyclic washing twice in 200mL absolute ethyl alcohol, finally wash in deionized water. the PVDF-g-PEGMA after washing is put into vacuum drying chamber inner drying,

Described polyvinylidene fluoride separation membrane preparation process is, PVDF-g-PEGMA is dissolved in NMP, mass fraction is 15%, after standing and defoaming, be coated on bright and clean glass plate with scraper under room temperature, place certain hour in atmosphere, make certain solvent volatilization. then immerse in deionized water, freezing film, film is dry in vacuum drying oven, obtain final finished.