阅读说明：本技术 改性聚苯醚及其制备方法、包含其的离子交换膜及制备方法和应用 (Modified polyphenyl ether, preparation method thereof, ion exchange membrane containing modified polyphenyl ether, preparation method and application ) 是由 鲁济豹 印浩 郭蕊 冉小能 孙蓉 于 2020-05-15 设计创作，主要内容包括：本发明提供了一种改性聚苯醚及其制备方法、包含其的离子交换膜及制备方法和应用,所述改性聚苯醚具有如式I所述结构。本发明提供的离子交换膜电导率较高,稳定性较好,且制备方法简单。(The invention provides modified polyphenyl ether and a preparation method thereof, an ion exchange membrane containing the modified polyphenyl ether, a preparation method and application of the ion exchange membrane, wherein the modified polyphenyl ether has a structure shown in a formula I. The ion exchange membrane provided by the invention has the advantages of higher conductivity, better stability and simple preparation method.)

1. A modified polyphenylene ether, wherein the modified polyphenylene ether has a structure according to formula I:

wherein n is an integer of 150-250;

wherein R is₁、R₂、R₃Each independently selected from substituted or unsubstituted aromatic groups.

2. The modified polyphenylene ether according to claim 1, wherein R is an aromatic ring-containing compound₁、R₂、R₃Each independently selected from substituted phenyl;

preferably, the substituents are selected from methoxy or ethoxy.

3. The modified polyphenylene ether according to claim 1 or 2, wherein the modified polyphenylene ether has a structure represented by the formula II:

wherein n is an integer of 150 and 250.

4. The method for producing a modified polyphenylene ether according to any one of claims 1 to 3, characterized by comprising the steps of:

carrying out substitution reaction on brominated polyphenylene oxide and a phosphine-containing compound to obtain the modified polyphenylene oxide;

wherein the phosphine-containing compound has the structure

R₁、R₂、R₃Having the same scope as claimed in claim 1.

5. The method according to claim 4, wherein the phosphine-containing compound is selected from tris (2,4, 6-trimethoxyphenyl) phosphine;

preferably, the mass ratio of the brominated polyphenylene ether to the phosphine-containing compound is 1 (1-1.2).

6. The process according to claim 4 or 5, wherein the substitution reaction is carried out at a temperature of 70 to 100 ℃ for 20 to 30 hours;

preferably, the substitution reaction is carried out in solution;

preferably, the concentrations of the brominated polyphenylene ether and the phosphine-containing compound in the solution are each independently selected from 0.01 to 0.05 g/mL;

preferably, the solvent of the solution is preferably 1-methyl-2-pyrrolidone.

7. The production method according to any one of claims 4 to 6, characterized in that the production method of the brominated polyphenylene ether comprises the steps of:

and reacting polyphenyl ether with N-bromosuccinimide under the action of an initiator to obtain the brominated polyphenyl ether.

8. The process according to claim 7, characterized in that the initiator is selected from radical initiators, preferably azobisisoheptonitrile and/or azobisisobutyronitrile;

preferably, the temperature of the reaction is 100-120 ℃, and the time is 10-20 h;

preferably, the mass ratio of the polyphenyl ether to the N-bromosuccinimide is 1 (1-1.2);

preferably, the reaction is carried out in a solvent;

preferably, the solvent is selected from chlorobenzene;

preferably, the reaction is carried out in a solvent, and the concentrations of the polyphenylene ether and the N-bromosuccinimide are each independently selected from 0.01 to 0.05 g/mL.

9. An ion-exchange membrane characterized in that the constituent components of the ion-exchange membrane comprise the modified polyphenylene ether of any one of claims 1 to 3;

preferably, the ion exchange membrane is composed of the modified polyphenylene ether according to any one of claims 1 to 3.

10. Use of an ion-exchange membrane according to claim 9 in a fuel cell.

Technical Field

The invention belongs to the technical field of modified polymers, and relates to modified polyphenyl ether, a preparation method thereof, an ion exchange membrane containing the modified polyphenyl ether, a preparation method and application of the ion exchange membrane.

Background

With the gradual depletion of energy resources and the increasing severity of environmental pollution, the development of energy with high efficiency and environmental protection is urgent. In recent years, fuel cells have come into the field of vision and received much attention as a new type of power equipment.

The fuel cell can directly convert chemical energy into electric energy through oxidation reaction, and is an energy source with great application prospect.The method adopts clean renewable energy sources such as hydrogen, methanol and the like, generates electric energy by oxidation-reduction reaction at the cathode and the anode, and obtains water and carbon dioxide as products to avoid environmental pollution. At present, two different fuel cells exist, one is that hydrogen is catalyzed into protons, and the protons pass through a proton exchange membrane, and an electrolyte moves to a positive electrode to be combined with oxygen of the positive electrode for reaction; the other is to catalyze the oxygen of the anode into OH^-And negative ions are transferred to the negative electrode through the negative ion exchange membrane and combined with the hydrogen. Among them, the fuel cell with anion exchange membrane is a kind of fuel cell with application prospect, and has been widely studied in recent years. Anion Exchange Membranes (AEMs) are the core components of anion exchange membrane fuel cells, which on the one hand play an important role in separating fuel and anion transport between anode and cathode, and on the other hand also determine the power output and service life of the fuel cell.

Polyphenyl ether is a polymer material with excellent comprehensive performance, can be dissolved in chlorobenzene, tetrahydrofuran and other organic solvents, has good film forming property, has the greatest characteristic of maintaining excellent dimensional stability and outstanding mechanical properties under long-term use load, has wide use temperature range and can be used for a long time within the range of-127-121 ℃.

CN108923056A discloses a preparation method of a novel high-conductivity polyphenyl ether anion exchange membrane, which comprises the steps of brominating and hydroxylating polyphenyl ether to obtain partially hydroxylated brominated polyphenyl ether, reacting the brominated polyphenyl ether with epoxy chloropropane, opening the ring of an epoxy group to form ether, reacting the obtained etherate with a quaternization reagent to introduce a conduction site, finally performing heat treatment to generate a cross-linked structure, and preparing the high-conductivity polyphenyl ether anion exchange membrane by a gel-sol process; the anion exchange membrane provided by the patent application has multiple conduction sites and higher ion conductivity, but the preparation method is too complicated and cannot be popularized and applied; and the stability of the material is poor. CN105237786A discloses a preparation method of a quaternized polyphenylene ether anion exchange membrane, which comprises the steps of firstly adding polyphenylene ether, 2-chloroacetic acid, a catalyst and a solvent into a reactor, stirring and reacting for 1-48 hours at 25-60 ℃, then slowly dripping reaction liquid into ethanol, filtering, soaking and washing precipitates with ethanol until the pH value is close to neutral, collecting the precipitates and drying to obtain 2-chloroacetyl modified polyphenylene ether; then adding 2-chloroacetyl modified polyphenyl ether and amine into a reactor, wherein the solid content is 5-20 wt%, stirring at 40 ℃ for reaction for 24h, then coating the reaction solution on a clean horizontal glass plate, naturally forming a film, and placing in an environment at 60 ℃ to volatilize the solvent to obtain the product; the anion exchange membrane provided by the patent application has increased ion exchange capacity, but the conductivity is still insufficient to meet the application requirements, and the stability of the material is poor.

Therefore, an ion exchange membrane with high conductivity, simple preparation method and good stability needs to be developed to meet the application requirements.

Disclosure of Invention

The invention aims to provide modified polyphenyl ether, a preparation method thereof, an ion exchange membrane containing the modified polyphenyl ether, a preparation method and application. The ion exchange membrane provided by the invention has the advantages of higher conductivity, better stability and simple preparation method.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a modified polyphenylene ether having a structure according to formula I:

wherein n is an integer of 150 and 250, such as 160, 180, 200, 210, 22, 230, 240, etc.

Wherein R is₁、R₂、R₃Each independently selected from substituted or unsubstituted aromatic groups.

Preferably, said R is₁、R₂、R₃Each independently selected from substituted phenyl.

Preferably, the substituents are selected from methoxy or ethoxy.

As a preferred technical scheme, the modified polyphenyl ether has a structure as shown in a formula II:

wherein n is an integer of 150 and 250, such as 160, 180, 200, 210, 22, 230, 240, etc.

When the composition of the ion exchange membrane comprises the structure, the structure can induce the nano phase separation of hydrophilic and hydrophobic phases, so that the ion exchange membrane has better conductivity and stability.

In a second aspect, the present invention provides a method for producing a modified polyphenylene ether according to the first aspect, comprising the steps of:

carrying out substitution reaction on brominated polyphenylene oxide (BrPPO) and a phosphine-containing compound to obtain the modified polyphenylene oxide;

wherein the phosphine-containing compound has the structure

R₁、R₂、R₃Having the same range as the first aspect.

Preferably, the phosphine-containing compound is selected from tris (2,4, 6-trimethoxyphenyl) phosphine.

Preferably, the mass ratio of the brominated polyphenylene ether to the phosphine-containing compound is 1 (1-1.2), such as 1:1.05, 1:1.1, 1:1.15, and the like.

Preferably, the temperature of the substitution reaction is 70-100 ℃, such as 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ and the like, for a period of 20-30h, such as 22h, 24h, 25h, 28h and the like.

Preferably, the substitution reaction is carried out in solution.

Preferably, the concentrations of the brominated polyphenylene ether and phosphine-containing compound in the solution are each independently selected from 0.01-0.05g/mL, such as 0.02g/mL, 0.03g/mL, 0.04g/mL, and the like.

Preferably, the solvent of the solution is preferably 1-methyl-2-pyrrolidone (NMP).

Preferably, the preparation method of the brominated polyphenylene ether comprises the following steps:

and (2) reacting polyphenylene oxide (PPO) with N-bromosuccinimide under the action of an initiator to obtain the brominated polyphenylene oxide.

Preferably, the initiator is selected from free radical initiators, preferably azobisisoheptonitrile and/or azobisisobutyronitrile.

Preferably, the reaction temperature is 100-120 ℃, such as 105 ℃, 110 ℃, 115 ℃ and the like, and the time is 10-20h, such as 12h, 14h, 15h, 18h and the like.

Preferably, the mass ratio of the polyphenylene ether to the N-bromosuccinimide is 1 (1-1.2), such as 1:1.05, 1:1.1, 1:1.15, etc.

Preferably, the reaction is carried out in a solvent.

Preferably, the solvent is selected from chlorobenzene.

Preferably, the reaction is carried out in a solvent, and the concentrations of the polyphenylene ether and N-bromosuccinimide are each independently selected from 0.01-0.05g/mL, such as 0.02g/mL, 0.03g/mL, 0.04g/mL, and the like.

In a third aspect, the present invention provides an ion exchange membrane, the composition of which comprises the modified polyphenylene ether of the first aspect.

Preferably, the ion-exchange membrane has a composition of the modified polyphenylene ether of the first aspect.

In a fourth aspect, the invention provides the use of an ion-exchange membrane according to the third aspect in a fuel cell.

Compared with the prior art, the invention has the following beneficial effects:

(1) the modified polyphenyl ether can generate the nano phase separation of hydrophilic phase and hydrophobic phase in the humidity region of the fuel cell operation, so that a channel for ion transportation is generated in a polymer dielectric film, and therefore, when the ion exchange membrane is prepared, the obtained ion exchange membrane has higher conductivity;

(2) when the modified polyphenyl ether is applied to an ion exchange membrane in a fuel cell, the ion exchange membrane has lower water absorption rate under the condition of the same humidity due to the introduction of the hydrophobic group, so that the great expansion in the use process is avoided, and the packaging is easy;

(3) the modified polyphenyl ether provided by the invention has good stability and a simple preparation method.

Drawings

Fig. 1 is a simulation diagram of an ion exchange membrane provided in example 1 of the present invention.

Fig. 2 is a simulation of the ion-exchange membrane provided in comparative example 1 of the present invention.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Preparation example 1

The preparation method of the brominated polyphenylene oxide comprises the following steps:

(1) dissolving polyphenyl ether and N-bromosuccinimide in chlorobenzene to prepare a mixed solution;

wherein the mass ratio of the polyphenyl ether to the N-bromosuccinimide is 1: 1;

in the mixed solution, the concentrations of polyphenylene ether and N-bromosuccinimide were each 0.05 g/mL.

(2) Azobisisoheptonitrile was added in an amount of 0.08mL to the mixed solution, which was stirred at 110 ℃ for 12 hours and then precipitated to give brominated polyphenylene ether.

Preparation example 2

The preparation method of the brominated polyphenylene oxide comprises the following steps:

(1) dissolving polyphenyl ether and N-bromosuccinimide in chlorobenzene to prepare a mixed solution;

wherein the mass ratio of the polyphenyl ether to the N-bromosuccinimide is 1: 1.2;

in the mixed solution, the concentration of polyphenylene ether was 0.02g/mL, and the concentration of N-bromosuccinimide was 0.01 g/mL.

(2) Azobisisoheptonitrile was added in an amount of 0.05mL to the mixed solution, which was stirred at 100 ℃ for 20 hours and then precipitated to give brominated polyphenylene ether.

Preparation example 3

The preparation method of the brominated polyphenylene oxide comprises the following steps:

(1) dissolving polyphenyl ether and N-bromosuccinimide in chlorobenzene to prepare a mixed solution;

wherein the mass ratio of the polyphenyl ether to the N-bromosuccinimide is 1: 1.1;

in the mixed solution, the concentration of polyphenylene ether was 0.03g/mL, and the concentration of N-bromosuccinimide was 0.04 g/mL.

(2) Azobisisobutyronitrile was added in an amount of 0.1mL to the mixed solution, stirred at 120 ℃ for 10 hours, and then precipitated to obtain brominated polyphenylene ether.