CN110563907A

CN110563907A - Preparation method of covalent organic framework material

Info

Publication number: CN110563907A
Application number: CN201910852359.4A
Authority: CN
Inventors: 孔祥正; 郭峰豪; 陈志勇
Original assignee: University of Jinan
Current assignee: University of Jinan
Priority date: 2019-09-09
Filing date: 2019-09-09
Publication date: 2019-12-13

Abstract

the invention relates to a preparation method of a covalent organic framework material. The covalent organic framework material can be prepared at room temperature by adopting a click reaction of a thiosulfydryl monomer of a triazine ring and an isocyanate-based monomer. The method has the advantages of mild conditions, simple and reliable preparation process, and wide application of the obtained material in the fields of gas storage, adsorption separation, electrochemistry and the like, wherein the method is characterized in that a sulfhydryl monomer, an isocyanate monomer and a solvent are uniformly mixed, the reaction is carried out for 4-96 h, and the product is washed by the solvent, centrifugally precipitated and dried to obtain the aromatic skeleton porous polymer material with a crystal structure.

Description

Preparation method of covalent organic framework material

Technical Field

The invention relates to a preparation method of a covalent organic framework material, belonging to the technical field of high polymer materials.

Background

At present, the porous polymer is widely applied to the aspects of adsorption separation, catalysis, gas and energy storage and the like because of the advantages of good stability, multifunction of a construction unit, adjustable pore size and the like.

Porous organic Polymers include Polymers with micropores (PIMs), hypercrosslinked Polymers (HCPs), Conjugated microporous organic Polymers (CMPs), porous aromatic frame materials (PAFs) and Covalent organic frame materials (CTFs) (reference Science 2015, 348, aa8075 aa). Covalent organic framework materials are materials in which organic molecules are linked by covalent bonds to form an ordered porous framework, and because the pore structure of the materials can be designed, the materials are widely concerned. The current methods for preparing covalent organic framework materials are mainly reactions based on boronic acid bonds, reactions based on triazine bonds and reactions based on imine bonds, etc. At present, the conditions of the methods for preparing COFs are harsh, and the large-scale preparation and application of the COFs are limited.

the reaction of sulfydryl and isocyanate group belongs to one of click chemistry, a metal catalyst is not needed in the reaction, the reaction condition is mild, the reaction is rapid, and the product yield is high. Chinese patents CN201611257501.3 and CN201910301879.6 disclose methods for preparing monodisperse polymer microspheres and porous microspheres by reacting thiol groups with isocyanate groups, respectively, but in the methods, acrylate thiol monomers and isocyanate group monomers are copolymerized, so that long-range ordered crystal structures are difficult to form. There are few reports of covalent organic framework materials prepared by this reaction.

Disclosure of Invention

Aiming at the limitations, the covalent organic framework material can be prepared by adopting the click reaction of the thiosulfydryl monomer (trithiocyanuric acid) of the triazine ring and the isocyanate-based monomer, the reaction condition is mild, the preparation process is simple and reliable, and the material is rich in nitrogen and sulfur elements and is expected to be applied to the fields of gas storage, electrochemistry and the like.

The technical scheme of the invention is as follows:

A preparation method of a porous material adopts the reaction of sulfydryl and isocyanate to prepare the porous material, and comprises the following steps:

adding trithiocyanuric acid, isocyanate monomer and catalyst into a solvent, uniformly mixing, placing in a reaction vessel, reacting at a certain temperature for 4 ~ 96 hours, washing and drying the obtained product by using the solvent to obtain a porous polymer material;

the trithiocyanuric acid is powder or trithiocyanuric acid crystal, wherein the preparation method of the trithiocyanuric acid crystal comprises the following steps: dissolving a certain amount of trithiocyanuric acid in N, N-dimethylformamide, adding a certain amount of water, placing in a 0 ℃ refrigerator, standing for 24 h, centrifuging the product, and drying in vacuum to remove the residual solvent to obtain white trithiocyanuric acid crystals;

The isocyanate group monomer is one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and triphenylmethane triisocyanate;

the ratio of the functional groups of the trithiocyanuric acid to the isocyanate monomer is 1 (1 ~ 4);

the ratio of the monomer to the solvent is (2 ~ 20) to 100;

The molar ratio of the catalyst to the monomer is (1-20): 100, respectively;

The solvent is as follows: one or more of dimethyl sulfoxide, tetrahydrofuran and N, N-dimethylformamide are mixed in any proportion;

According to the invention, the reaction time is preferably controlled between 4 and 24 hours.

Preferably according to the invention, the molar ratio of catalyst to monomer is (1-10): 100, respectively;

according to a preferred embodiment of the present invention, a method for preparing a porous polymer material comprises the following steps:

Adding 0.89 g of trithiocyanuric acid, 1.31 g of toluene diisocyanate and 3.2 mu L of triethylamine into 20 mL of dimethyl sulfoxide, uniformly mixing, standing at room temperature for 24 h for reaction, washing the obtained product with dimethyl sulfoxide and ethanol, and drying to constant weight to obtain the porous polymer material.

According to a preferred embodiment of the present invention, a method for preparing a covalent organic framework material comprises the following steps:

dissolving 400 mg of trithiocyanuric acid by using 10 mL of N, N dimethylformamide, adding 10 mL of water, uniformly mixing, standing in a refrigerator at 0 ℃ for 24 h, performing centrifugal separation, and performing vacuum drying to obtain a white solid product. And (3) taking 200 mg of the dried product, adding 1 mL of toluene diisocyanate, reacting at room temperature for 4 h, washing the product with n-hexane, and drying at room temperature in vacuum to constant weight to obtain the porous polymer material with the crystal structure.

the invention adopts the reaction of sulfydryl and isocyanate to prepare the porous polymer material, the reaction condition is mild, and the aromatic skeleton porous polymer material with a crystal structure can be prepared.

Drawings

FIG. 1 is a scanning electron micrograph of a covalent organic framework material according to example 2.

FIG. 2 is a drawing of the nitrogen adsorption stripping of the covalent organic framework material of example 2.

FIG. 3 is a scanning electron micrograph of a covalent organic framework material according to example 5.

figure 4 is an XRD pattern of the covalent organic framework material of example 5.

Detailed Description

example 1

1.31 g of toluene diisocyanate and 0.89 g of trithiocyanuric acid are added into 20 mL of dimethyl sulfoxide, the mixture is uniformly mixed, the mixture is kept stand at room temperature for reaction for 96 hours, the obtained product is washed by dimethyl sulfoxide and ethanol, the product is dried to constant weight, and the yield of the obtained porous material is 83.8%.

Example 2

Adding 1.31 g of toluene diisocyanate, 0.89 g of trithiocyanuric acid and 3.2 mu L of triethylamine into 20 mL of dimethyl sulfoxide, uniformly mixing, standing at room temperature for 24 hours for reaction, washing the obtained product with dimethyl sulfoxide and ethanol, drying to constant weight, wherein the yield of the obtained porous material is 54.0%, and the specific surface area is 62.6 m²/g。

example 3

2.62 g of toluene diisocyanate and 1.78 g of trithiocyanuric acid are added into 20 mL of dimethyl sulfoxide, the mixture is uniformly mixed, the mixture is kept stand at room temperature for 24 hours to react, the obtained product is washed by dimethyl sulfoxide and ethanol, the product is dried to constant weight, the yield of the obtained porous material is 41.3%, and the specific surface area is 24.78 m²/g。

Example 4

2.62 g of toluene diisocyanate and 1.78 g of trithiocyanuric acid are added into 20 mL of dimethyl sulfoxide, the mixture is uniformly mixed, the reaction is carried out for 4 h at 80 ℃, the obtained product is washed by dimethyl sulfoxide and ethanol, the drying is carried out until the weight is constant, and the yield of the obtained porous material is 88.7%.

Example 5

Dissolving 400 mg of trithiocyanuric acid by using 10 mL of N, N dimethylformamide, adding 10 mL of water, uniformly mixing, standing in a refrigerator at 0 ℃ for 24 h, performing centrifugal separation, and performing vacuum drying to obtain a white solid product. And (3) taking 200 mg of the dried product, adding 1 mL of toluene diisocyanate, reacting at room temperature for 4 h, washing the product with n-hexane, and drying at room temperature in vacuum to constant weight.

example 6

Dissolving 400 mg of trithiocyanuric acid by using 10 mL of N, N dimethylformamide, adding 10 mL of water, uniformly mixing, standing in a refrigerator at 0 ℃ for 24 h, performing centrifugal separation, and performing vacuum drying to obtain a white solid product. And taking 200 mg of the dried product, adding 1 mL of isophorone diisocyanate, reacting for 4 h at room temperature, washing the product with n-hexane, and drying in vacuum at room temperature to constant weight.

Claims

1. A method for preparing a covalent organic framework material is characterized in that a porous polymer material is prepared by click reaction of a mercapto group and an isocyanate group, and the steps are as follows:

adding trithiocyanuric acid, isocyanate monomer and catalyst into a solvent, uniformly mixing, placing in a reaction container, wherein the mass ratio of the two monomers to the solvent is 2 ~ 40:100, the catalyst is triethylamine, the reaction time is 4 ~ 96 hours, and washing and drying the obtained product by using the solvent to obtain the porous polymer material.

2. the method of claim 1, wherein: the reaction form of the trithiocyanuric acid and the isocyanate monomer is two:

(1) dissolving trithiocyanuric acid and isocyanate monomer in a solvent, and copolymerizing the trithiocyanuric acid and the isocyanate monomer through the reaction of a mercapto group and an isocyanate group to form a porous polymer;

(2) Firstly, preparing cyanuric acid crystal, and reacting isocyanate monomer with mercapto in the cyanuric acid crystal to obtain porous polymer; wherein, the cyanuric sulfate crystal is prepared by adopting a method of crystallizing the cyanuric sulfate crystal at a certain temperature by using a cosolvent.

3. the cosolvent is one of N, N ~ dimethylformamide, acetone and tetrahydrofuran, and is mixed with water according to a certain proportion, and the temperature is ~ 18 ~ 0 ℃.

4. as set forth in claim 1: isocyanate-based monomers used: toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate.

5. As set forth in claim 1: the reaction solvent is as follows: one or more of dimethyl sulfoxide, tetrahydrofuran and N, N-dimethylformamide are mixed in any proportion.

6. As set forth in claim 1: the reaction temperature is 20-80 DEG C

The method of claim 1, wherein: the reaction time is controlled to be 4 to 96 hours.

7. The method of claim 1, wherein: and washing the product by adopting one or more of dimethyl sulfoxide, ethanol, acetone and n-hexane.