CN1200029C - Polyphthalazone with sulfosalt lateral group and its preparation method - Google Patents

Abstract

The present invention discloses novel polyphthalazone ether sulfone with sulfosalt side groups and a method for preparing the novel polyphthalazone ether sulfone. The polymer is formed by that novel monomers, namely 4, 4-dihalo (or dinitro)-3, 3-disulfonate diphenyl sulfone, dihalo (or dinitro) diphenyl sulfone and bisphenol like monomers containing phthalazone structure are used as raw materials, alkali or salt of alkali metal is used as catalysts, and the polymer is obtained through high temperature co-polymerization in polar solvent or reaction media with polar solvent as a main part. The polymer has the advantages of large molecular weight, poor swelling property, favorable mechanical property, high glass transition temperature and favorable high temperature oxidation resisting property. The polymer can be used as a component of a positive electrode of a proton exchange membranes and has a bright application prospect. R1 and R2 are hydrogen atoms, C1 to C4 are linear alkyl groups or phenyl groups, or branched alkyl groups or phenyl groups, M is a sodium ion or a potassium ion, and m+n is larger than or equal to 20.

Description

Polyphthalazinone ether sulfone with sulfonate side groups and preparation method thereof

Technical field:

The invention relates to a polyphthalazinone ether sulfone, in particular to a polyphthalazinone ether sulfone with sulfonate side groups and a preparation method thereof.

Background technique:

The development of proton exchange membrane material is one of the key technologies of proton exchange membrane fuel cell (PEMFC). The earliest proton exchange membrane material used in PEMFC was polystyrene sulfonic acid membrane. Because of its poor stability and conductivity, and a service life of only 500 hours, it is difficult to be used in PEMFC. In the 1980s, new high-performance and long-life perfluorosulfonic acid proton exchange membrane materials were successfully developed, such as Dupond's Nafion membrane, which is a perfluorosulfonic acid membrane.

The successful development of perfluorosulfonic acid proton exchange membrane has made the development of PEMFC a hot spot. This type of membrane has several advantages: low membrane resistivity, large ion exchange capacity; excellent heat resistance, can withstand the working temperature of 100 °C for a long time; excellent comprehensive performance, chemical stability, selective permeability, new processability, etc. Item performed well. Its disadvantages are: high methanol permeability, low electrical conductivity at high temperature and low humidity, expensive, and cannot be directly applied to methanol fuel cells.

Following the Nafion membrane, Canada's Ballard Corporation invented a new fluoride proton exchange membrane material, such as the fluoride membrane reported in US P5,773,480. The electrochemical performance test results show that at high current densities, its performance is better than that of Nafion membrane.

Whether it is a perfluorinated proton exchange membrane or a fluorinated proton exchange membrane, because the polymerized monomer must be a fluorinated monomer, its variety is greatly limited, and the price is very expensive, so more and more researchers turn to non-fluorinated proton exchange membranes. Research on exchange membranes. J. Appl. Electrochem., V26, 751-756 (1996) reported phosphoric acid doped polybenzimidazole (PBI) films. Compared with Nafion membrane, it has three obvious advantages: good thermal stability, long-term resistance to working temperature of 150--200°C; dry film proton conductivity is superior to Nafion membrane; methanol permeability is low, only 1/ of Nafion membrane 10. Its disadvantage is that there is still a large membrane resistance and low power conversion efficiency. The research on phosphoric acid doped polybenzimidazole film has just started, and further research is needed.

In order to prepare a proton exchange membrane for PEMFC with excellent comprehensive performance and low price, people try to prepare polyarylethersulfone-based and polyaryletherketonesulfonic acid membranes. There are two preparation methods for this type of film, one is direct sulfonation of polymers, such as J.Polym.Sci.: Polym.Chem., V22, 721-737 (1984) reported that polyarylene ether was directly sulfonated with a sulfonating agent The invention discloses a method for preparing polyaryl ether sulfone sulfonic acid membrane by sulfone sulfonation. The method is simple and convenient, but there are degradation and crosslinking, and the degree of sulfonation is also difficult to control. Moreover, the sulfonic acid group is directly connected to the ortho position of the oxygen of the bisphenol unit, so that it is prone to hydrolysis and detachment in a long-term high-temperature working environment. Another method is to first sulfonate a polymerized monomer and then polymerize it with other monomers. Such as J. Polym.: Part A, Polym. Chem., V31, 853-858 (1993) reported this new method. Dichlorodiphenyl sulfone is firstly sulfonated to obtain sulfonated dichlorodiphenyl sulfone monomer, which is copolymerized with dichlorodiphenyl sulfone and bisphenol monomer to prepare polyarylethersulfone sulfonic acid membrane. The characteristic structure of its polymer is as follows:

There is no side reaction such as degradation and crosslinking in the reaction process, and the sulfonation degree of the product can be conveniently controlled. At the same time, because the sulfonic acid group is located on the benzene ring of the diphenyl sulfone unit in the polymer chain, it is more stable than the sulfonic acid group located in the bisphenol unit. However, the oxidation resistance of the polyarylethersulfone sulfonic acid membrane decreases due to the presence of methyl hydrogen in the molecular chain; and the swelling property becomes severe with the increase of the sulfonic acid group content.

In general, polyethersulfone-based sulfonic acid membranes with ideal conductivity cannot be directly used as proton exchange membranes because they swell too much in water. This membrane material usually needs to add a second component to form an appropriate amount of hydrogen bonds, ionic bonds or covalent bonds to reduce the degree of swelling to the applicable range.

Invention content:

The purpose of the present invention is to start from the molecular structure design, adopt bisphenol-like monomers containing a naphthyridine ring structure, and directly prepare a new type of polynaphthyridine ether sulfone with sulfonic acid side groups by copolymerization. Because the carbonyl group of the phthalazine ring structure and the electron-rich nitrogen heteroatom form hydrogen bonds with the hydroxyl hydrogen of the sulfonic acid, the physical crosslinking degree of the membrane material is improved, and the swelling degree of the membrane material is significantly reduced, thereby improving its performance as a proton exchange agent. Comprehensive properties of membrane materials. In this way, this sulfonic acid membrane material does not need to add a second component to reduce the degree of swelling, but can be directly used as a proton exchange membrane, which greatly simplifies the membrane manufacturing process, and is useful for the preparation of proton exchange membranes with low swelling degree and excellent comprehensive performance. Membrane provides a new way of thinking.

The diphenyl sulfone monomer used in the present invention is 4,4'-difluoro (chloro, bromo or nitro) diphenyl sulfone.

The sulfonated diphenyl sulfone monomer used in the present invention is 4,4'-difluoro (chloro, bromo or nitro)-3,3'-disulfonate diphenyl sulfone.

The bisphenol-like monomer containing the diazanaphthyrone structure that the present invention adopts has a molecular structural formula of:

Wherein, R ₁ and R ₂ are hydrogen atoms, C ₁ -C ₄ straight-chain, branched-chain alkyl groups or phenyl groups. Such as 4-(4-hydroxyphenyl)-2,3-naphthyridine-1-one, 4-(3,5-dimethyl-4-hydroxyphenyl)-2,3-naphthyridine -1-one or 4-(3,5-diphenyl-4-hydroxyphenyl)-2,3-phthalazin-1-one, etc.

The polymerization reaction temperature adopted in the present invention is 140-220 DEG C, and the reaction time is 1-36 hours.

The polymerization reaction solvent that the present invention adopts is the aprotic polar solvent such as dimethyl sulfoxide, sulfolane, diphenyl sulfone, N-methylpyrrolidone, N, N-dimethylformamide or the mixed solvent based on it as reaction medium.

The azeotropic dehydrating agent used in the present invention is toluene (xylene or chlorobenzene).

The product precipitation agent that the present invention adopts is water and methanol (or ethanol).

The polymerization process of the present invention is as follows: the sulfonated diphenyl sulfone monomer and diphenyl sulfone monomer are mixed with bisphenol-like monomers containing a dizinone structure in an equimolar ratio, an alkali or an alkali metal salt of a certain amount of alkali metal , toluene (xylene or chlorobenzene), solvent, etc. were added to the three-necked flask. Under the protection of nitrogen, heat up and dehydrate. After dehydration, discharge the azeotropic dehydrating agent, heat up to 140-220°C, polymerize for 1-36 hours, cool naturally, precipitate, filter, and dry. Repeat three times to obtain the target product. And test its physical and chemical properties.

The equation of polyreaction of the present invention can be expressed as:

Wherein, R ₁ and R ₂ are hydrogen atoms, C ₁ -C ₄ straight chain, branched chain alkyl or phenyl,

M is sodium ion or potassium ion,

X is fluorine, chlorine, bromine atom or nitro

m+n is greater than or equal to 20

The structure of the polymer prepared by the invention is confirmed by infrared spectrum and nuclear magnetic resonance analysis methods. By adjusting the ratio of sulfonated monomers, reaction temperature and reaction time, target products with different sulfonic acid group contents and different viscosities can be prepared, thereby adjusting the conductivity and other properties of the products. The polyphthalazinone ether sulfone with sulfonate side group of high molecular weight that the present invention prepares is a kind of novel proton exchange membrane material, compares with polyether sulfone base proton exchange membrane, has lower degree of swelling, Better high temperature oxidation resistance. It can be cast into a film, soluble in N, N-dimethylformamide, and the toughness is very good after the solution is formed into a film and dried. The resin has high strength.

Detailed ways:

The following examples are to further illustrate the present invention, but not to limit the scope of the present invention.

Example 1: 1.2834 grams (2.8 mmol) of 4,4'-difluoro-3,3'-disulfonate sodium diphenyl sulfone, 1.0679 grams (4.2 mmol) of 4,4'-difluoro diphenyl sulfone, 1.6677 Gram (7mmol) 4-(4-hydroxyphenyl)-2,3-naphthyridine-1-one and 1.1609 grams (8.4mmol) potassium carbonate, 30ml toluene, 20ml sulfolane join in the there-necked flask, in the there-necked flask Access to nitrogen, water separator with condenser, equipped with a mechanical stirrer. Under the protection of nitrogen, heat up and dehydrate. After dehydration, discharge the azeotropic dehydrating agent toluene, heat up to 200 ° C, polymerize for 10 hours, after natural cooling, add solvent to dilute, precipitate in water, filter, repeat three times, in a vacuum oven Dry at 100°C to obtain the target product. The reduced viscosity of the product is 1.74dl/g, and the temperature at which the thermal weight loss is 10% is 533°C.

Example 2: 0.9625 grams (2.1 mmol) of 4,4'-difluoro-3,3'-disulfonate sodium diphenyl sulfone, 1.2459 grams (4.9 mmol) of 4,4'-difluoro diphenyl sulfone, 1.6677 Gram (7mmol) 4-(4-hydroxyphenyl)-2,3-naphthyridine-1-ketone and 1.1609 grams (8.4mmol) potassium carbonate, 30ml toluene, 20ml sulfolane join in the there-necked flask, in the there-necked flask Access to nitrogen, water separator with condenser, equipped with a mechanical stirrer. Under the protection of nitrogen, heat up and dehydrate. After dehydration, discharge the azeotropic dehydrating agent toluene, heat up to 200 ° C, polymerize for 10 hours, after natural cooling, add solvent to dilute, precipitate in water, filter, repeat three times, in a vacuum oven Dry at 100°C to obtain the target product. The reduced viscosity of the product is 1.45dl/g, and the temperature at which the thermal weight loss is 10% is 534°C.

Claims (7)

1. be with the poly-naphthyridine ether ketone sulfone of pendant sulfonate, it is characterized in that the repeated structural unit of polymkeric substance is:

Wherein, R ₁, R ₂Be hydrogen atom, C ₁-C ₄Straight chain, branched-chain alkyl or phenyl,

M is sodium ion or potassium ion,

N＞0, and m+n is more than or equal to 20.

2. be with the preparation method of the poly-naphthyridine ether ketone sulfone of pendant sulfonate; it is characterized in that with 44 '-dihalo-or dinitrobenzene-3,3 '-stilbene-4,4'-bis-(1-azo-3, 4-dihydroxy-benzene)-2,2'-disulfonate sulfobenzide; 4; 4 '-dihalo-or diphenylsulfone dinitro and the class biphenol monomer that contains two assorted quinoline ketone structures are in master's the reaction medium at aprotic polar solvent or aprotic polar solvent, are catalyzer with alkali-metal alkali or its salt; under nitrogen protection; in the presence of azeotropy dehydrant, the heat temperature raising dehydration is after dehydration finishes; discharge azeotropy dehydrant; carry out polymerization, reaction adds solvent cut after finishing in the system; in precipitation agent, precipitate; separate drying, three times repeatedly, obtain subject polymer.

3. the preparation method of the poly-naphthyridine ether ketone sulfone of the described band pendant sulfonate of root a tree name claim 2 is characterized in that adopting the class biphenol monomer that contains two assorted azepine naphthalenone structures, and its molecular formula is:

Wherein, R ₁, R ₂Be hydrogen atom, C ₁-C ₄Straight chain, branched-chain alkyl or phenyl.

4. the preparation method of the poly-naphthyridine ether ketone sulfone of the described band pendant sulfonate of root a tree name claim 2 is characterized in that polymeric reaction temperature is 140～220 ℃, and the reaction times is 1～36 hour.

5. the preparation method of the poly-naphthyridine ether ketone sulfone of the described band pendant sulfonate of root a tree name claim 2, it is characterized in that with dimethyl sulfoxide (DMSO), tetramethylene sulfone, sulfobenzide, N-Methyl pyrrolidone or N, the dinethylformamide aprotic polar solvent as reaction medium or based on its mixed solvent as reaction medium.

6. the preparation method of the poly-naphthyridine ether ketone sulfone of the described band pendant sulfonate of root a tree name claim 2 is characterized in that making azeotropy dehydrant with toluene, dimethylbenzene or chlorobenzene.

7. the preparation method of the poly-naphthyridine ether ketone sulfone of the described band pendant sulfonate of root a tree name claim 2 is characterized in that water, methyl alcohol or ethanol makes precipitation agent.