CN104226127A - Preparation method of graphene/polyurethane hybridized gas separation membrane and product of preparation method - Google Patents

Abstract

The invention discloses a preparation method of a graphene/polyurethane hybrid gas separation membrane. Functionalized graphene is mixed with N,N-dimethylformamide to obtain a mixed liquid, and after ultrasonic dispersion is uniform, 1 , 4-butanediol, 4,4-diphenylmethane diisocyanate and dibutyltin dilaurate are heated in a water bath to 40-50°C for polymerization reaction. When the viscosity of the reaction system is 90-110mPa·s, the reaction liquid Coating on a porous support body, heat treatment at 50-70° C. for 10-20 hours, and drying to obtain the graphene/polyurethane hybrid gas separation membrane. The invention effectively introduces the graphene into the polyurethane membrane through the in-situ polymerization reaction, improves the dispersion performance of the graphene on the one hand, and effectively improves the gas separation performance of the polyurethane membrane at the same time.

Description

A kind of preparation method and product of graphene/polyurethane hybrid gas separation membrane

technical field

The invention relates to the technical field of gas separation membranes, in particular to a preparation method of a graphene/polyurethane hybrid gas separation membrane and a product thereof.

Background technique

Polyurethane (PU) is polymerized from isocyanate and polyol, and is a block copolymer with alternating soft/hard segments and microphase separation structure. Polyurethane materials have various types and controllable properties, and have the advantages of good mechanical properties, tensile resistance, good film-forming properties and easy processing. In addition, the soft/hard segment alternating molecular structure of polyurethane and its microphase separation structure endow polyurethane as a promising membrane material with good application value.

In order to further improve the gas separation performance of polyurethane membranes, Shadi Hassanajili et al. (ShadiHassanajili, Mohammadamin Khademi, PeymanKeshavarz. Influence of various types of silica nanoparticles on permeation properties of polyurethane/silica mixed matrix membranes, Journal of MembraneScience, 2014, 453, 369) studied each of the 38–38 Effects of different types of _SiO2 nanoparticles on the permeation properties of PU/ _SiO2 hybrid membranes. Mohammad AliSemsarzadeh et al. (MohammadAliSemsarzadeh Behnam Ghalei. Preparation, characterization and gaspermeation properties of polyurethane–silica/polyvinyl alcohol mixed matrixmembranes, Journal of Membrane Science, 2012, 432, 115–125) proposed a hybrid membrane of PU-ASiO ₂ /PV Preparation and characterization, and the gas permeability of the hybrid membrane was studied. Morteza Sadeghi et al. (Morteza Sadeghi, Mohammad Mehdi Talakesh, Behnam Ghalei. Preparation, characterization and gas permeation properties of a polycaprolactone based polyurethane-silica nanocomposite membrane, Journal of Membrane Science, 2013, 427, 21–29) studied _2- based PU-SiO Preparation, characterization and gas permeation properties of polycaprolactone in nanoparticle films. As another example, Shadi Hassanajil et al. (Shadi Hassanajili, Esmaiel Masoudi, Gholamreza Karimi, Mohammadamin Khademi. Mixed matrix membranes based on polyesterurethane and polyester-urethane containing silica nanoparticles for separation of CO ₂ /CH ₄ gases, Separation and Purification Technology 1 12), Morteza Sadeghia et al. (Morteza Sadeghia, Mohammad Ali Semsarzadeh, Mehdi Barikani. Gas separation properties of polyester-based polyurethane-silicananocomposite membranes, Journal of Membrane Science, 2011, 376, 188–195) added nano-SiO ₂ particles to polyurethane to prepare organic Inorganic hybrid membranes have also obtained good results.

Graphene is a new type of two-dimensional planar nanomaterial, which is composed of a dense layer of carbon atoms wrapped in a honeycomb crystal lattice. It is the thinnest two-dimensional material in the world, with a thickness of only 0.35nm. This special single atomic layer structure determines that graphene has rich and novel physical properties. Compared with known inorganic nanomaterials, graphene has extremely high adsorption and permeability as a separation material. The study found that the transfer rate of small molecules in graphene is several orders of magnitude faster than that in ordinary polymer membranes or molecular sieve membranes. The unique structure and properties of graphene are destined to provide an alternative new material for gas separation membranes.

Contents of the invention

The invention provides a preparation method of a graphene/polyurethane hybrid gas separation membrane, which effectively introduces graphene into the polyurethane membrane by using an in-situ polymerization reaction, thereby improving the gas separation performance of the polyurethane membrane.

A preparation method of carbon graphene/polyurethane hybrid gas separation membrane, comprising the steps of:

Mix functionalized graphene with N,N-dimethylformamide to obtain a mixed solution, and after ultrasonic dispersion is uniform, add 1,4-butanediol, 4,4-diphenylmethane diisocyanate and diphenylmethane diisocyanate to the mixed solution Dibutyltin laurate, heated in a water bath to 40-50°C for polymerization reaction, when the viscosity of the reaction system is 90-110mPa·s, coat the reaction solution on the porous support, heat treatment at 50-70°C for 10-20h , and then dried to obtain the graphene/polyurethane gas separation membrane.

The functionalized graphene is graphene oxide obtained after chemical modification, amine functionalized graphene, acyl chloride graphene or isocyanate functionalized graphene.

Described graphene oxide can be obtained by commercially available, also can according to literature (Da Chen, Hongbin Feng, and Jinghong Li.Graphene Oxide:Preparation, Functionalization, and Electrochemical Applications.Chem.Rev.,2012,112(11), 6027–6053) to prepare;

The amine-functionalized graphene can be obtained commercially, or according to the literature (Functionalization of Graphene: Covalent and Non-covalent Approaches, Derivatives and Applications. Chem Rev, 2012, 112 (11): 6156-6214) method for preparation;

The acyl chloride graphene can be prepared according to the method in the literature (Functionalization of Graphene: Covalent and Non-covalent Approaches, Derivatives and Applications.ChemRev, 2012,112(11):6156-6214);

The isocyanate functionalized graphene can be prepared according to the method in the literature (Functionalization of Graphene: Covalent and Non-covalent Approaches, Derivatives and Applications. Chem Rev, 2012, 112 (11): 6156-6214).

Preferably, the mass concentration of functionalized graphene in the mixed solution is 3.75-8.75 g/L.

As preferably, the molar ratio of the 1,4-butanediol and 4,4-diphenylmethane diisocyanate is 0.5 to 5.0:1; the amount of the functionalized graphene is 4,4-diphenyl 0.1-1.5% of the total mass of phenylmethane diisocyanate and 1,4-butanediol.

When the functionalized graphene is graphene oxide,

Preferably, the content of the oxygen-containing functional group is 2.5 to 3.5% by weight; the amount of the graphene oxide is 0.4 to 1.0% of the total mass of 4,4-diphenylmethane diisocyanate and 1,4-butanediol %.

Further preferably, the oxygen-containing functional group content of the graphene oxide is 3 wt%, and the feed amount of the graphene oxide is 0.43% of the total mass of 4,4-diphenylmethane diisocyanate and 1,4-butanediol.

When described functionalized graphene is amine functionalized graphene,

Preferably, the amino group content of the amine-functionalized graphene is 3 to 5 wt%, and the amount of the amine-functionalized graphene is the total mass of 4,4-diphenylmethane diisocyanate and 1,4-butanediol 0.7～1.0% of 0.7～1.0%; Further preferably, the amino content of described amine-functionalized graphene is 4.5wt%, and the charging amount of amine-functionalized graphene is 4,4-diphenylmethane diisocyanate and 1,4-butanedi 0.71% of the total mass of alcohol.

When the functionalized graphene is isocyanated graphene,

Preferably, the isocyanate content of the isocyanated graphene is 5 to 7 wt%, and the amount of isocyanate-functionalized graphene is the total mass of 4,4-diphenylmethane diisocyanate and 1,4-butanediol 0.7～1.0%; more preferably, the content of isocyanate is 5.6wt%, and the feeding amount of isocyanate-functionalized graphene is 1.0% of the total mass of 4,4-diphenylmethane diisocyanate and 1,4-butanediol .

As a preference,

When the viscosity of the polymerization reaction system is controlled to be 100 mPa·s, the reaction solution is coated on a porous support; the porous support is a polysulfone porous support membrane.

The heat treatment temperature is 60° C. and the time is 12 hours.

A graphene/polyurethane hybrid gas separation membrane obtained according to the preparation method.

Compared with prior art, the present invention has following advantage:

The invention effectively introduces the graphene into the polyurethane membrane through the in-situ polymerization reaction, improves the dispersion performance of the graphene on the one hand, and effectively improves the gas separation performance of the polyurethane membrane at the same time.

Detailed ways

The following specific examples are used to further illustrate how to prepare a graphene/polyurethane hybrid gas separation membrane using the present invention, and the gas permeability of the prepared hybrid membrane.

Gas separation performance evaluation of graphene/polyurethane hybrid membrane:

At 25°C and 0.2Mpa operating pressure, the gas permeation volume per unit membrane area per unit time (under standard conditions) was used to evaluate the gas separation performance of the graphene/polyurethane hybrid membrane.

Example 1

①Weigh 40ml of N,N-dimethylformamide (DMF), weigh 0.15g of graphene oxide (oxygen-containing functional group content is 3wt%) into a beaker, ultrasonically disperse it and put it in a water bath at 45°C;② Weigh 10g of 1,4-butanediol (BDO) into the beaker and stir fully; ③ Weigh 25g of 4,4-diphenylmethane diisocyanate and measure 45μL of dibutyltin dilaurate into the beaker to stir and react , until the viscosity of the system is about 100mPa·s; ④Invert the obtained viscous solution on the polysulfone porous support membrane and scrape the film evenly (control the wet film thickness to 0.1mm); ⑤Put the polysulfone porous support membrane coated with viscous solution Put into oven 60 ℃ and process 12 hours, obtain graphene/polyurethane hybrid membrane, ⑥ put the graphene/polyurethane hybrid membrane that obtains into 45 ℃ of vacuum ovens and dry for 12 hours, remove the residual organic matter (hybrid) in the film The final thickness of the membrane separation layer is 50.2 μm); ⑦ Under the conditions of 0.2MPa and 25°C, the permeability of H ₂ , O ₂ , N ₂ , CH ₄ , and CO ₂ of the membrane was tested by a gas permeation meter. The test results are shown in Table 1.

Example 2

① Measure 40ml of N,N-dimethylformamide (DMF), weigh 0.25g of amine-functionalized graphene (-NH ₂ content about 4.5wt%) and add it to a beaker, ultrasonically disperse it and place it in a water bath at 45°C ② Weigh 15g of 1,4-butanediol (BDO) into the beaker and stir fully; ③ Weigh 20g of 4,4-diphenylmethane diisocyanate, measure 45μL of dibutyltin dilaurate into the beaker Stir and react until the viscosity of the system is about 100mPa·s; ④ Invert the viscous solution obtained on the polysulfone porous support membrane and scrape the film evenly (control the wet film thickness to 0.1mm); ⑤ Apply the viscous solution on the surface Put the sulfone porous support membrane in an oven at 60°C for 12 hours to obtain a graphene/polyurethane hybrid membrane. Organic matter (the final thickness of the separation layer of the hybrid membrane is 50.3 μm); ⑦ Under the conditions of 0.2MPa and 25°C, the permeability of H ₂ , O ₂ , N ₂ , CH ₄ , and CO ₂ of the membrane was tested by a gas permeation instrument, and the test results See Table 1.

Example 3

① Measure 40ml of N,N-dimethylformamide (DMF), weigh 0.35g of isocyanate-functionalized graphene (-NCO content 5.6wt%) into a beaker, and put it into a water bath at 45°C after ultrasonic dispersion; ②Weigh 20g of 1,4-butanediol (BDO) into the beaker and stir well; ③Weigh 15g of 4,4-diphenylmethane diisocyanate and measure 45μL of dibutyltin dilaurate into the beaker and stir , react until the viscosity of the system is about 100mPa·s; ④Invert the viscous solution obtained on the polysulfone porous support membrane and scrape the film evenly (control the wet film thickness to 0.1mm); The supporting film was put into an oven at 60° C. for 12 hours to obtain a graphene/polyurethane hybrid film. 6. The obtained graphene/polyurethane hybrid film was put into a 45° C. vacuum oven and dried for 12 hours to remove residual organic matter ( The final thickness of the separation layer of the hybrid membrane is 50.3μm); ⑦under the conditions of 0.2MPa and 25°C, the permeability of H ₂ , O ₂ , N ₂ , CH ₄ , and CO ₂ of the membrane was tested by a gas permeation instrument. The test results are shown in the table 1.

comparative example

①Weigh 40ml of N,N-dimethylformamide, weigh 10g of 1,4-butanediol into a beaker, and stir fully in a water bath at 45°C; ②Weigh 25g of 2,4-toluene- Diisocyanate, measure 45 μL of dibutyltin dilaurate and add it into a beaker to stir and react until the system viscosity is about 100mPa·s; 0.1mm); ④Put the polysulfone porous support membrane coated with viscous liquid in an oven for 12 hours at 60°C to obtain a polyurethane film; ⑤Put the obtained polyurethane film in a 45°C vacuum oven to dry for 12 hours, remove Residual organic matter in the membrane (the final thickness of the membrane separation layer is 50.2 μm); ⑥ Under the conditions of 0.2MPa and 25°C, the permeability of H ₂ , O ₂ , N ₂ , CH ₄ , and CO ₂ of the membrane was tested by a gas permeation instrument. The test results are shown in Table 1.

Table 1

Table 1 lists the permeability of the gas separation membranes prepared in Examples 1-3 and Comparative Examples to H ₂ , O ₂ , N ₂ , CH ₄ , CO ₂ , where P _H2 represents the permeability coefficient of H ₂ , Others represent the same meaning. Compared with pure PU membranes, the addition of functionalized graphene can significantly improve the gas permeability and permeation selectivity of PU membranes.

Claims (9)

1. a preparation method for Graphene/polyurethane hybrid gas separation membrane, is characterized in that, comprise the steps:

By functionalization graphene and N, dinethylformamide is mixed to get mixed liquor, after ultrasonic disperse is even, in mixed liquor, add BDO, 4,4-methyl diphenylene diisocyanate and dibutyl tin laurate, polymerisation is carried out in heating water bath to 40 ~ 50 DEG C, when question response system viscosity is 90 ~ 110mPas, is coated in by reactant liquor on porous supporting body, at 50 ~ 70 DEG C after heat treatment 10 ~ 20h, then drying obtains described Graphene/polyurethane hybrid gas separation membrane.

2. the preparation method of Graphene according to claim 1/polyurethane hybrid gas separation membrane, is characterized in that, described functionalization graphene is graphene oxide, amino-functionalization Graphene, chloride Graphene or isocyanate functionalized Graphene.

3. the preparation method of Graphene according to claim 2/polyurethane hybrid gas separation membrane, is characterized in that, in described mixed liquor, the concentration of functionalization graphene is 3.75 ~ 8.75g/L.

4. the preparation method of Graphene according to claim 3/polyurethane hybrid gas separation membrane, is characterized in that, the molar ratio of described BDO and 4,4-methyl diphenylene diisocyanate is 0.5 ~ 5.0:1;

The inventory of described functionalization graphene is 0.1 ~ 1.5% of 4,4-methyl diphenylene diisocyanate and BDO gross mass.

5. the preparation method of Graphene according to claim 4/polyurethane hybrid gas separation membrane, is characterized in that, described functionalization graphene is graphene oxide, and the content of oxygen-containing functional group is 2.5 ~ 3.5wt%; The inventory of described graphene oxide is 0.4 ~ 1.0% of 4,4-methyl diphenylene diisocyanate and BDO gross mass.

6. the preparation method of Graphene according to claim 4/polyurethane hybrid gas separation membrane, is characterized in that, described functionalization graphene is amino-functionalization Graphene, and amino content is 3 ~ 5wt%; The inventory of described amino-functionalization Graphene is 0.7 ~ 1.0% of 4,4-methyl diphenylene diisocyanate and BDO gross mass.

7. the preparation method of Graphene according to claim 4/polyurethane hybrid gas separation membrane, is characterized in that, described functionalization graphene is isocyanate functionalized Graphene, and isocyano-content is 5 ~ 7wt%; The inventory of described isocyanate functionalized Graphene is 0.7 ~ 1.0% of 4,4-methyl diphenylene diisocyanate and BDO gross mass.

8. the preparation method of Graphene according to claim 1/polyurethane hybrid gas separation membrane, is characterized in that, described heat treatment temperature is 60 DEG C, and the time is 12h.

9. Graphene/polyurethane hybrid gas separation membrane of obtaining of a preparation method according to claim 1.