阅读说明：本技术 一种燃料电池用侧链型高温质子交换膜及其制备方法 (A kind of fuel cell side chain type high temperature proton exchange film and preparation method thereof ) 是由 卢善富 白慧娟 相艳 王海宁 张劲 于 2019-08-14 设计创作，主要内容包括：本发明公开了一种燃料电池用侧链型高温质子交换膜及其制备方法。该方法首先将工程塑料聚合物氯甲基化,然后通过原子转移自由基聚合反应,将乙烯基咪唑接枝到聚合物侧链上,得到聚乙烯基咪唑基侧链型聚合物,将所得聚合物采用溶剂溶解后流延或溶液涂铸成膜,脱膜后再进行酸化处理,得到具有高温质子导电能力的聚合物电解质膜材料。该高温质子交换膜材料均相、透明、致密,同时具有优异机械性能、高温质子导电性和化学稳定性,可满足高温质子交换膜燃料电池(100-200℃)的应用要求。该质子交换膜还可用作液流电池、高温电池、超级电容器等器件的隔膜材料。(The invention discloses a kind of fuel cell side chain type high temperature proton exchange films and preparation method thereof.This method is first by engineering plastics polymer chloromethylation, then pass through atom transition free radical polymerization reaction, vinyl imidazole is grafted on polymer lateral chain, obtain polyvinyl imidazol base side chain type polymer, resulting polymers are cast into film using curtain coating after solvent dissolution or solution painting, acidification is carried out after demoulding again, obtains the polymer dielectric film material with high temperature proton conducting ability.The high temperature proton exchange film material is homogeneous, transparent, fine and close, while having very good mechanical properties, high temperature proton conductive and chemical stability, can meet the application requirement of high temperature proton exchange film fuel cell (100-200 DEG C).The proton exchange membrane also acts as the diaphragm material of the devices such as flow battery, high-temperature battery, supercapacitor.)

1. a kind of fuel cell preparation method of side chain type high temperature proton exchange film, which comprises the following steps:

(1) chloromethylation of polymer

Engineering plastics polymer is dissolved in the first solvent, zinc powder and trifluoroacetic acid is then added, is stirred at 20~50 DEG C After 0.5-2 hours, chloromethyl ether is added dropwise, is reacted again after being added dropwise 0.5-5 hours, mixture after reaction is poured into It is precipitated in first precipitating reagent, is then successively filtered, washed, dry, obtain chloromethylated polymer；

(2) polymer lateral chain atomic radicals polymerize

Chloromethylated polymer obtained in step (1) is dissolved in the second solvent, is then added under the conditions of anhydrous and oxygen-free CuCl or CuBr and bipyridyl obtain reaction mixture, and the ratio between the CuCl or the amount of substance of CuBr and bipyridyl are 1:1 ~1:5, vinyl imidazole monomer (VIm) is added after stirring 0.5-2 hours at 20~50 DEG C in the reaction mixture, described The additional amount of vinyl imidazole monomer (VIm) is 20~200 times of the amount of the substance of CuCl or CuBr, then at 50~100 DEG C Reaction mixture after reaction is poured into the second precipitating reagent and is precipitated by isothermal reaction 12-48h in range, is obtained white Color flocculent deposit filters, then successively filters, wash, dry, obtain the side-chain polymer of vinyl imidazole functionalization；

(3) it forms a film

Side-chain polymer obtained in step (2) is dissolved in third solvent and obtains casting solution, then in clean matrix Upper film forming, heating, drying is up to thin polymer film；

(4) acid doping post-processes

The thin polymer film that step (3) obtains is impregnated in the mixture solution of phosphoric acid, heteropoly acid or both, until reaching Saturation inhales acid amount, and attachment acid remained on surface is wiped after taking-up, obtains high temperature proton exchange film material.

2. preparation method according to claim 1, which is characterized in that engineering plastics polymer described in step (1) is poly- Sulfone (PSF), polyphenylsulfone (PPSF), polyarylsulfone (PAS) (PASF), phenolic polyether sulphone (PES-C) or polyphenylene oxide (PPO).

3. preparation method according to claim 1, which is characterized in that the first solvent described in step (1) be dichloroethanes, The combination of one or more of tetrachloroethanes, chloroform.

4. preparation method according to claim 1, which is characterized in that the object of zinc powder and trifluoroacetic acid described in step (1) The amount ratio of matter is 1:0.5~1:3, preferably are as follows: 1:1.2~1:1.5.

5. preparation method according to claim 1, which is characterized in that the first precipitating reagent described in step (1) is methanol, second Alcohol or acetone, the solvent of washing are methanol, ethyl alcohol or acetone.

6. preparation method according to claim 1, which is characterized in that the second solvent described in step (2) is N, N- diformazan Base formamide (DMF), n,N-dimethylacetamide (DMAc), N-Methyl pyrrolidone (NMP), in dimethyl sulfoxide (DMSO) One or more combinations, the second precipitating reagent described in step (2) be methanol, ethyl alcohol or acetone, the solvent of washing be methanol, Ethyl alcohol or acetone.

7. preparation method according to claim 1, which is characterized in that third solvent described in step (3) is N, N- diformazan Base formamide (DMF), n,N-dimethylacetamide (DMAc), N-Methyl pyrrolidone (NMP), in dimethyl sulfoxide (DMSO) One or more combinations.

8. preparation method according to claim 1, which is characterized in that form a film on clean matrix described in step (3) Specifically: it is dried at a temperature of 50-120 DEG C, film formation time is 10-24 hours.

9. preparation method according to claim 1, which is characterized in that using the phosphoric acid of mass fraction 85% in step (4) 40~96h of aqueous solution soaking, the temperature of immersion are 25~80 DEG C.

10. a kind of high temperature proton exchange film obtained by any preparation method of claim 1-9, which is characterized in that described High temperature proton exchange film is used as the diaphragm material of flow battery, high-temperature battery, alkaline battery.

Technical field

The invention belongs to field of fuel cell technology more particularly to a kind of side chain type high temperature proton exchange film and its preparation sides Method.

Background technique

Proton Exchange Membrane Fuel Cells can directly convert the chemical energy in fuel to as a kind of energy conversion device Electric energy has many advantages, such as that starting speed is fast, energy conversion efficiency is high, energy density is big, pollution-free.It is fired with low-temperature protonic exchange membrane Material battery is compared, and high temperature proton exchange film fuel cell has faster due to working under higher temperature (100-200 DEG C) The foreign gases anti-poisoning abilities such as electrode reaction dynamics, better carbon monoxide (CO) and the hydro-thermal management system simplified form For one of the important development direction of Proton Exchange Membrane Fuel Cells.High temperature proton exchange film is high temperature proton exchange film fuel cell Core component, play the role of transmit proton and obstruct fuel infiltration, directly decide output performance, cost and the longevity of battery Life.

Phosphate-doped nitrogen-containing heterocycle polymeric film material, especially phosphate-doped polybenzimidazoles (PBI) proton are handed over Changing film, (conductivity is generally 4 × 10 at 150 DEG C due to having high ionic conductivity under high temperature low humidity/anhydrous condition^-2~ 8×10^-2S cm^-1Between), good chemical stability etc. and become the research hotspot of high temperature membrane material.Such membrane material from Electron conductivity and mechanical property are directly related with amount phosphate-doped in film, and the ionic conductivity of the phosphate-doped higher film of amount is more Height, but the equal rapid decrease of dimensional stability and mechanical property of film simultaneously, can seriously affect the stability of battery operation, the service life and Safety.Cause the basic reason of the above problem be such high molecular material absorb phosphoric acid active site (nitrogen-containing heterocycle contains Nitrogen groups) it is respectively positioned on high polymer main chain or close on the side chain of main chain, with a large amount of introducings of proton conductor phosphoric acid, macromolecule The interaction of interchain substantially weakens, and seriously affects membrane material mechanical property and dimensional stability.

In view of the above-mentioned problems, current universal Research Thinking is using the enhancing of porous fibre (such as porous PTFE) physics, altogether It mixes, be chemically crosslinked the methods of (ionomer or covalently cross-linked) to improve its mechanical property.These improved methods are really very The mechanical property of high temperature membrane material can be improved in big degree, but bring some new problems simultaneously: for example, fibre-reinforced multiple Closing high temperature membrane there are problems that being easy to appear reinforcing fiber and the removing of film basis material after absorbing phosphoric acid；Using ionomer side Method, acidic polymer are easy to produce polymer salt precipitating and cause to be stranded to film when being dissolved in same solvent with alkaline polymer It is difficult；And being chemically crosslinked can make membrane material lose a part of phosphate adsorption site, so that membrane conductivity is reduced to a certain extent, And the degraded toughness of film.Therefore, the predicament that high temperature proton exchange film is faced at present is solved, it is necessary to from the chemistry knot of membrane material Structure sets out, and carries out source design, synthesizing new high temperature polymer electrolyte membrane material to macromolecular chain.

Summary of the invention

In view of the above-mentioned problems, the object of the present invention is to provide a kind of side chain type high temperature proton exchange film and its preparation sides The high temperature proton exchange film of method, this method preparation not only has a good mechanical performance and high proton conductivity, also have compared with Strong phosphoric acid conservation rate.

Technical solution of the present invention is specific as follows:

A kind of preparation method of fuel cell side chain type high temperature proton exchange film, comprising the following steps:

(1) chloromethylation of polymer

Engineering plastics polymer is dissolved in the first solvent, zinc powder and trifluoroacetic acid is then added, is stirred at 20~50 DEG C After mixing 0.5-2 hours, chloromethyl ether is added dropwise, is reacted again after being added dropwise 0.5-5 hours, mixture after reaction is fallen Enter and precipitated in the first precipitating reagent, then successively filtered, washs, dries, obtain chloromethylated polymer.

(2) polymer lateral chain atomic radicals polymerize

Chloromethylated polymer obtained in step (1) is dissolved in the second solvent, is then added under the conditions of anhydrous and oxygen-free Enter CuCl or CuBr and bipyridyl obtain reaction mixture, the ratio between the CuCl or the amount of substance of CuBr and bipyridyl are 1: Vinyl imidazole monomer (VIm) is added after stirring 0.5-2 hours at 20~50 DEG C in 1~1:5, the reaction mixture, institute 20~200 times of the amount for the substance that the additional amount for stating vinyl imidazole monomer (VIm) is CuCl or CuBr, then 50~100 Reaction mixture after reaction is poured into the second precipitating reagent and is precipitated, obtained by isothermal reaction 12-48h within the scope of DEG C White flock precipitate filters, then successively filters, wash, dry, obtain the side-chain polymer of vinyl imidazole functionalization.

(3) it forms a film

Side-chain polymer obtained in step (2) is dissolved in third solvent and obtains casting solution, then in cleaning It forms a film on matrix, heating, drying is up to thin polymer film.

(4) acid doping post-processes

The thin polymer film that step (3) obtains is impregnated in the mixture solution of phosphoric acid, heteropoly acid or both, is taken out After wipe attachment remained on surface acid, obtain high temperature proton exchange film material.

Further, engineering plastics polymer described in step (1) has superior heat-stability and chemical stability.

Further, engineering plastics polymer described in step (1) is polysulfones (PSF), polyphenylsulfone (PPSF), polyarylsulfone (PAS) (PASF), phenolic polyether sulphone (PES-C) or polyphenylene oxide (PPO).

Further, the first solvent described in step (1) is one of dichloroethanes, tetrachloroethanes, chloroform or more The combination of kind.

Further, the mass ratio of the material of zinc powder described in step (1) and trifluoroacetic acid is 1:0.5~1:3, preferably are as follows: 1:1.2~1:1.5.

Further, the first precipitating reagent described in step (1) be methanol, ethyl alcohol or acetone, the solvent of washing be methanol, Ethyl alcohol or acetone.

Further, the second solvent described in step (2) is n,N-Dimethylformamide (DMF), N, N- dimethylacetamide One of amine (DMAc), N-Methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO) or a variety of combinations, institute in step (2) Stating the second precipitating reagent is methanol, ethyl alcohol or acetone, and the solvent of washing is methanol, ethyl alcohol or acetone；

Further, third solvent described in step (3) is n,N-Dimethylformamide (DMF), N, N- dimethylacetamide One of amine (DMAc), N-Methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO) or a variety of combinations.

Further, it forms a film on clean matrix described in step (3) specifically: done at a temperature of 50-120 DEG C Dry, film formation time is 10-24 hours.

Further, 40~96h, the temperature of immersion are impregnated using the phosphate aqueous solution of mass fraction 85wt% in step (4) Degree is 25~80 DEG C.

Preparation method of the invention has the following beneficial effects:

(1) present invention moves to the functional group for absorbing phosphoric acid on polymer lateral chain from the main chain of traditional polymer, reduces Plastication of the phosphoric acid absorbed to high polymer main chain, ensure that high temperature proton exchange film while having high proton conductivity And mechanical property.

(2) vinyl imidazole group is grafted on polymer molecular chain by the present invention by atomic radicals polymerization reaction, The length (degree of polymerization) of ethenyl of side chain imidazoles can be regulated and controled by reaction time, reaction temperature and feed ratio, to reach To the target of regulation high temperature proton exchange film proton conductivity and mechanical property, thus this kind of membrane material high temperature proton exchange film fires Expect that field of batteries has biggish application potential.

Detailed description of the invention

In order to illustrate more clearly of technical solution of the present invention, letter will be made to attached drawing needed in the embodiment below Singly introduce, it should be apparent that, for those of ordinary skills, without any creative labor, It is also possible to obtain other drawings based on these drawings.

Fig. 1 is the synthetic route schematic diagram of preparation method of the present invention；

Fig. 2 is the mechanical performance curve graph of the high temperature proton exchange film of 1-3 of embodiment of the present invention preparation at room temperature；

Fig. 3 is the high temperature proton exchange film proton conductivity curve at different temperatures of 1-3 of embodiment of the present invention preparation；

Fig. 4 is the monocell performance of the high temperature proton exchange film of the preparation of the embodiment of the present invention 3 at different temperatures.

Specific embodiment

The present invention provides a kind of preparation of side chain type high temperature proton exchange film, prepared high temperature proton exchange film is equal Mutually transparent, transparent, dense membrane has excellent thermal stability, mechanical performance and high temperature proton conductivity.

After preparation method of the invention mainly includes the high molecular synthesis of modified side chain, solution-cast film and protonates Three steps are managed, preparation process route map is as shown in Figure 1, specific as follows:

(1) chloromethylation of polymer

Engineering plastics polymer with superior heat-stability and chemical stability is dissolved in suitable organic solvent (such as dichloroethanes, tetrachloroethanes, chloroform) is formed to reaction polymer solution, concentration 5-20wt%, preferred concentration 8- 15wt%, optimum concentration range 9-12wt%.

Then it is added a certain amount of zinc powder and trifluoroacetic acid, usual mass ratio is 1:0.5~1:3, optimal ratio are as follows: 1: 1.2~1:1.5.

The reaction system is stirred under 20~50 DEG C (different according to selected engineering plastics, reaction temperature is adjusted correspondingly) A certain amount of chloromethyl ether is added dropwise after mixing 0.5-2 hours, and (the amount range of chloromethyl ether is 10-100mL, according to engineering plastics and phase The chloromethylation of prestige is adjusted at degree difference), the reaction was continued 0.5-5 hours after being added dropwise dropwise, will after reaction Reaction mixture is poured into precipitating reagent and is precipitated, and is then successively filtered, and is washed, is dried, obtains containing chloromethylated polymer； The chloromethylation degree of engineering plastics is between 15~150%, preferably 50-60%.

(2) polymer lateral chain atomic radicals polymerize

Obtained chloromethylated polymer is dissolved in suitable solvent (such as DMAc, DMF, NMP, DMSO, according to different chlorine Methylated polymer object and adjust), concentration 0.05-0.1wt%, then under the conditions of anhydrous and oxygen-free by CuCl or CuBr and connection pyrrole Pyridine is added into polymer solution according to a certain percentage (the ratio between amount of substance is 1:1~1:5)；The reaction system is 20~50 It according to the ratio between amount of substance of CuCl (or CuBr) and vinyl imidazole monomer (VIm) is 1:20 after being stirred 0.5-2 hours at DEG C Suitable vinyl imidazole monomer, the isothermal reaction 12-48h within the scope of 50~100 DEG C is added in~1:200；It will after reaction Reaction mixture pour into precipitating reagent and precipitated, obtain white flock precipitate, filter, then successively filter, wash, do It is dry, obtain the side-chain polymer of vinyl imidazole functionalization.Each graft site, which is calculated, through nuclear-magnetism detection is grafted imidazoles function The number of group.

(3) it forms a film

Resulting polymers are dissolved in suitable solvent (such as DMAc, DMF, NMP, DMSO, according to different vinyl imidazole function The side-chain polymer of energyization and adjust), obtain polymer solution, concentration 1-15wt%, preferable concentration is usually 3- 10wt%, optimum concentration range 4-8wt%.

Obtained coating solution is filtered after mixing evenly, take its filtrate figure casting on clean matrix, 60-120 DEG C (according to According to the difference of selected solvent, film-forming temperature is adjusted accordingly) under it is dry, volatilize completely to solvent, obtain homogeneous membrane.

(4) acid doping post-processes

The above-mentioned homogeneous membrane prepared is immersed in certain concentration phosphoric acid/and heteropoly acid solution and is impregnated 40-96 hours It is wiped after (composition of foundation film and different choose for protonating processing solution handle the time accordingly) taking-up film remained on surface The high temperature proton exchange film with high conductance energy can be obtained in acid.

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.