Polybenzimidazole resin solution suitable for proton exchange membrane and preparation method of polybenzimidazole resin solution

Abstract

The invention relates to the technical field of resin materials, and discloses a polybenzimidazole resin solution suitable for a proton exchange membrane and a preparation method thereof, the polybenzimidazole resin solution comprises the following raw materials by mass: 50-60 parts of polybenzimidazole resin, 10-20 parts of a modifier, 5-10 parts of a reinforcing filler, 50-60 parts of a phosphoric acid solution, and 80-100 parts of a solvent. The modifier contains a large number of flexible long chains and can endow the polybenzimidazole resin with good flexibility, and the modifier interacts with the polybenzimidazole resin to weaken hydrogen bonds between molecular chains of the polybenzimidazole resin and improve the solubility of the polybenzimidazole resin; the reinforcing filler serves as a lubricating component, movement of a polybenzimidazole resin molecular chain is facilitated, and the flowability of a polybenzimidazole resin solution is improved.

Description

Technical Field

[0001] The invention relates to the technical field of resin materials, in particular to a polybenzimidazole resin solution suitable for a proton exchange membrane and a preparation method thereof. Background Art

[0002] Polybenzimidazole is a polymer material with excellent performance synthesized by the reaction of aromatic tetraamine and aliphatic or aromatic dicarboxylic acid ester. It uses benzimidazole as the repeating unit, its molecular chain is highly rigid and arranged regularly, and has high glass transition temperature, thermal decomposition temperature, chemical stability and mechanical properties. It is widely used in high-temperature resistant jackets, space suits, heat-resistant films, diaphragms, reinforced plastics, foam materials, etc. Among them, polybenzimidazole resin solution is used for proton exchange membranes, and has broad application prospects in electric vehicles and mobile portable devices. It has good proton conductivity, low price, reliability and durability.

[0003] The high rigidity of the polybenzimidazole molecular structure and the strong hydrogen bonding between molecules make it poorly soluble and difficult to process, which limits the application of polybenzimidazole resin solution in proton exchange membranes. The solubility of polybenzimidazole resin can be effectively improved by introducing flexible groups or side chains into the polybenzimidazole molecular chain. However, the introduction of flexible groups can easily reduce the thermal stability of polybenzimidazole resin, and high molecular weight polybenzimidazole has poor fluidity during the dissolution process, resulting in high engineering difficulty in stirring, dissolving, filtering, degassing, and film scraping or spinning. Summary of the invention

[0004] The invention provides a polybenzimidazole resin solution suitable for a proton exchange membrane and a preparation method thereof, which solves the problems of poor solubility and difficult processing of the polybenzimidazole resin.

[0005] The technical solution of the present invention:

[0006] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 50-60 parts of a polybenzimidazole resin, 10-20 parts of a modifier, 5-10 parts of a reinforcing filler, 50-60 parts of a phosphoric acid solution, and 80-100 parts of a solvent;

[0007] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0008] Add polybenzimidazole resin to the solvent, rotate and stir at 125-135° C. for 1-3 hours, add modifier, phosphoric acid solution and reinforcing filler, stir at 200-300 r / min for 20-30 minutes, and degas by vacuum decompression for 10-14 hours to obtain a polybenzimidazole resin solution.

[0009] The modifier is obtained by mixing a coumarin derivative and a eugenol derivative and then performing emulsion copolymerization;

[0010] The reinforcing filler is prepared by mixing kaolin and glucose, carbonizing them at high temperature, and then mixing and reacting with itaconic acid and phytic acid.

[0011] Furthermore, the solvent is N,N-dimethylacetamide.

[0012] Furthermore, the phosphoric acid solution is a phosphoric acid aqueous solution with a mass fraction of 80-90%.

[0013] Furthermore, the molecular weight of the polybenzimidazole resin is 5.5×10 5 -6.5×10 5 .

[0014] Further, the modifier is prepared by the following steps:

[0015] A1. Add 7-hydroxycoumarin to N,N-dimethylacetamide, stir evenly, add triethylamine and methacryloyl chloride, stir at 30-40°C for 10-12h, add methanol, distill under reduced pressure, filter, wash and dry to obtain a coumarin derivative;

[0016] A2. Eugenol was added to ethanol, stirred evenly, hydroxyethyl methacrylate and sodium hydroxide were added, and the reaction was stirred until the organic solvent evaporated, the solid was removed, washed, and dried to obtain a eugenol derivative;

[0017] A3. Mix the coumarin derivative and the eugenol derivative, stir until dissolved to obtain a monomer mixture, mix sodium dodecyl sulfate, sodium bicarbonate, sodium metabisulfite and deionized water, stir evenly, add the monomer mixture, heat to 45-55°C, stir and react after completion, cool to room temperature, wash and dry to obtain a modifier.

[0018] Furthermore, in the above reaction process A1, in the organic solvent N,N-dimethylacetamide, triethylamine is used as a catalyst to allow the hydroxyl group in 7-hydroxycoumarin to undergo a substitution reaction with the chlorine atom in methacryloyl chloride, so that methacryloyl chloride is grafted onto 7-hydroxycoumarin to obtain a coumarin derivative.

[0019] Furthermore, in the above reaction process A2, sodium hydroxide is used as a catalyst in the organic solvent ethanol, so that the hydroxyl groups of hydroxyethyl methacrylate can undergo an etherification reaction with the hydroxyl groups in eugenol, so that hydroxyethyl methacrylate is grafted onto eugenol to form a eugenol derivative.

[0020] Furthermore, in the above-mentioned A3 reaction process, the coumarin derivative and the eugenol derivative are mixed, and sodium metabisulfite is used as an initiator to copolymerize the double bonds in the coumarin derivative and the eugenol derivative to form a stable polymer emulsion, which contains a large amount of flexible long chains and can give the polybenzimidazole resin better flexibility.

[0021] Furthermore, in step A1, the amount ratio of 7-hydroxycoumarin, 50-60 parts of phosphoric acid aqueous solution, N,N-dimethylacetamide, triethylamine, methacryloyl chloride, and methanol is (4-6) g: (15-25) mL: (20-30) mL: (7-8) mL: (90-110) mL.

[0022] Furthermore, in step A2, the ratio of eugenol, ethanol, hydroxyethyl methacrylate and sodium hydroxide is (3-4) g: (15-25) mL: (4-6) mL: (0.2-0.4) g.

[0023] Furthermore, in step A3, the mass ratio of the coumarin derivative to the eugenol derivative is (2.5-2.9):(2.3-2.5).

[0024] Furthermore, in step A3, the amount ratio of sodium dodecyl sulfate, sodium bicarbonate, sodium metabisulfite, deionized water, and monomer mixture is (1.6-2) g: (1.5-1.9) g: (0.8-1.1) g: (25-35) mL: (5-5.2) g.

[0025] Further, the reinforcing filler is prepared by the following steps:

[0026] B1. Add kaolin and glucose to ethanol, stir at 60-80°C for 25-35min, filter, wash, dry, mix with potassium hydroxide aqueous solution, stir evenly, carbonize at 750-850°C for 1-3h, cool to room temperature, take out, wash, and dry to obtain modified kaolin;

[0027] B2. Add itaconic acid and phytic acid to deionized water, stir evenly, react at 60-70°C for 25-35 minutes, add modified kaolin, stir evenly, add ammonium persulfate and polyethylene glycol, react at 90-100°C for 30-40 minutes, cool to room temperature, filter, wash and dry to obtain a reinforced filler.

[0028] Furthermore, during the above-mentioned B1 reaction process, the hydroxyl groups contained on the surface of kaolin can be chemically bonded with the oxygen-containing functional groups in glucose, so that the glucose is coated on the surface of kaolin. After high-temperature carbonization, the glucose is thermally decomposed to form a dense carbon layer. The potassium hydroxide aqueous solution is used as an activator to form pores on the surface of the dense carbon layer, thereby realizing the synthesis of porous carbon on the surface of kaolin. The synthesized porous carbon has high adsorption properties and can adsorb and fix impurities in kaolin.

[0029] Furthermore, in the above-mentioned B2 reaction process, itaconic acid and phytic acid are combined through chemical bonds, and ammonium persulfate is used as a catalyst to polymerize the double bonds carried by itaconic acid to form a polymer. The carboxyl and hydroxyl groups carried by the formed polymer can be combined with the oxygen-containing functional groups on the surface of the modified kaolin through chemical bonds to form a cross-linked network structure, i.e., a reinforcing filler.

[0030] Furthermore, in step B1, the ratio of kaolin, glucose, ethanol and potassium hydroxide aqueous solution is (5-6) g: (6-7) g: (50-70) mL: (8-12) mL.

[0031] Furthermore, in step B2, the usage ratio of itaconic acid, phytic acid, deionized water, modified kaolin, ammonium persulfate and polyethylene glycol is (1-2) g: (1-3) g: (45-55) mL: (5-6) g: (0.1-0.3) g: (1-2) g.

[0032] The present invention has the following beneficial effects:

[0033] (1) In the technical scheme of the present invention, coumarin derivatives and eugenol derivatives are copolymerized to form a stable polymer emulsion, which, as a modifier, contains a large amount of flexible long chains, and can give the polybenzimidazole resin good flexibility. The benzene ring structure on the modifier molecular chain can interact with the benzene ring on the polybenzimidazole resin molecular chain, and can weaken the hydrogen bonds between the polybenzimidazole resin molecular chains, thereby improving the solubility of the polybenzimidazole resin, so that the proton exchange membrane formed by the polybenzimidazole resin solution has a higher proton conductivity.

[0034] (2) In the technical solution of the present invention, porous carbon is synthesized on the surface of kaolin. On the one hand, the synthesized porous carbon has high adsorption performance and can adsorb and fix impurities in kaolin to prevent the impurities in kaolin from falling into the polybenzimidazole resin solution and affecting the performance of the polybenzimidazole resin. On the other hand, the porous carbon has a large specific surface area and pore volume and can interact with the polybenzimidazole resin molecules. Kaolin, as an inorganic carrier, can penetrate into the polybenzimidazole resin, so that the reinforcing filler acts between the molecular chains of the polybenzimidazole resin and acts as a lubricating component, which is beneficial to the movement of the molecular chains of the polybenzimidazole resin, improves the fluidity of the polybenzimidazole resin solution, and is beneficial to the polybenzimidazole resin solution to better form a proton exchange membrane. In addition, kaolin, as an inorganic material, has high mechanical properties and improves the mechanical strength of the polybenzimidazole resin.

[0035] (3) In the technical scheme of the present invention, itaconic acid and phytic acid are combined by chemical bonds, and ammonium persulfate is used as a catalyst to polymerize the double bonds carried by itaconic acid to form a polymer. The carboxyl and hydroxyl groups carried by the formed polymer can be combined with the oxygen-containing functional groups on the surface of the modified kaolin by chemical bonds to form a cross-linked network structure. On the one hand, the formed cross-linked network structure has higher mechanical properties and improves the mechanical strength of the polybenzimidazole resin. On the other hand, the polymer formed by itaconic acid and phytic acid is coated on the surface of the modified kaolin, which improves the dispersibility of the modified kaolin in the polybenzimidazole resin and avoids the agglomeration and precipitation of the modified kaolin. In addition, itaconic acid and phytic acid can further improve the high temperature resistance of the polybenzimidazole resin.

[0036] (4) In the technical solution of the present invention, the polybenzimidazole resin solution also contains a phosphoric acid solution. The phosphoric acid solution, as a cross-linking agent, can increase the cross-linking density of the polybenzimidazole resin. The phosphoric acid can also be combined with the modifier and the reinforcing filler through chemical bonds, so that the modifier and the reinforcing filler are evenly dispersed in the polybenzimidazole resin solution, while preventing the loss of phosphoric acid molecules from the proton exchange membrane, thereby having a higher proton conductivity. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The raw materials used in the examples of the present invention are as follows, and all reagents used are of analytical grade.

[0039] The solvent is N,N-dimethylacetamide.

[0040] The phosphoric acid solution is a phosphoric acid aqueous solution with a mass fraction of 85%.

[0041] The molecular weight of polybenzimidazole resin is 6×10 5 .

[0042] The particle size of kaolin is 1.5 μm.

[0043] Example 1

[0044] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 50 parts of a polybenzimidazole resin, 10 parts of a modifier, 5 parts of a reinforcing filler, 50 parts of a phosphoric acid aqueous solution, and 80 parts of N,N-dimethylacetamide;

[0045] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0046] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 125°C for 1 hour. A modifier, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 200 r / min for 20 minutes. The mixture was defoamed by vacuuming for 10 hours to obtain a polybenzimidazole resin solution.

[0047] The modifier is prepared by the following steps:

[0048] A1. Add 4 g of 7-hydroxycoumarin to 15 mL of N,N-dimethylacetamide, stir evenly, add 20 mL of triethylamine and 7 mL of methacryloyl chloride, stir at 30°C for 10 h, add 90 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water three times, and dry in an oven at 60°C for 10 min to obtain a coumarin derivative;

[0049] A2. 3 g of eugenol was added to 15 mL of ethanol, stirred evenly, 4 mL of hydroxyethyl methacrylate and 0.2 g of sodium hydroxide were added, and the mixture was stirred at 65 ° C for 10 min, and the mixture was heated to 85 ° C and stirred until the organic solvent evaporated. The solid was taken out, washed with deionized water until the pH of the washing liquid was neutral, and dried in an oven at 60 ° C for 10 min to obtain a eugenol derivative;

[0050] A3. Mix 2.5 g of coumarin derivative and 2.3 g of eugenol derivative, heat at 40°C until completely dissolved to obtain a monomer mixture, mix 1.6 g of sodium dodecyl sulfate, 1.5 g of sodium bicarbonate, 0.8 g of sodium metabisulfite and 25 mL of deionized water, stir for 30 min, add 5 g of the monomer mixture, heat to 45°C, and stir at 200 rpm for 4 h, cool to room temperature, wash with ethanol 3 times, wash with deionized water 5 times, and dry in an oven at 60°C for 15 min to obtain a modifier.

[0051] The reinforcing filler is prepared by the following steps:

[0052] B1. Add 5 g of kaolin and 6 g of glucose to 50 mL of ethanol, stir at 60 ° C for 25 min, filter, wash with deionized water three times, dry in an oven at 70 ° C for 10 min, mix with 8 mL of potassium hydroxide aqueous solution by mass fraction, stir evenly, carbonize at 750 ° C for 1 h, cool to room temperature, take out, wash with deionized water three times, and dry in an oven at 70 ° C for 10 min to obtain modified kaolin;

[0053] B2. Add 1g of itaconic acid and 1g of phytic acid to 45mL of deionized water, stir evenly, react with stirring at 60°C for 25min, add 5g of modified kaolin, stir evenly, add 0.1g of ammonium persulfate and 1g of polyethylene glycol, react with stirring at 90°C for 30min, cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70°C for 10min to obtain a reinforced filler.

[0054] Example 2

[0055] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 55 parts of a polybenzimidazole resin, 15 parts of a modifier, 8 parts of a reinforcing filler, 55 parts of a phosphoric acid aqueous solution, and 90 parts of N,N-dimethylacetamide;

[0056] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0057] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 130°C for 2 hours. A modifier, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 250 r / min for 25 minutes. The mixture was defoamed by vacuuming for 12 hours to obtain a polybenzimidazole resin solution.

[0058] The modifier is prepared by the following steps:

[0059] A1. Add 5 g of 7-hydroxycoumarin to 20 mL of N,N-dimethylacetamide, stir evenly, add 25 mL of triethylamine and 7.5 mL of methacryloyl chloride, stir at 35°C for 11 h, add 100 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water three times, and dry in an oven at 60°C for 10 min to obtain a coumarin derivative;

[0060] A2. 3.5 g of eugenol was added to 20 mL of ethanol, stirred evenly, 5 mL of hydroxyethyl methacrylate and 0.3 g of sodium hydroxide were added, and the mixture was stirred at 65 ° C for 10 min, and the mixture was heated to 85 ° C and stirred until the organic solvent evaporated. The solid was taken out, washed with deionized water until the pH of the washing liquid was neutral, and dried in an oven at 60 ° C for 10 min to obtain a eugenol derivative;

[0061] A3. Mix 2.7 g of coumarin derivative and 2.4 g of eugenol derivative, heat at 40°C until completely dissolved to obtain a monomer mixture, mix 1.8 g of sodium dodecyl sulfate, 1.7 g of sodium bicarbonate, 0.9 g of sodium metabisulfite and 30 mL of deionized water, stir for 30 min, add 5.1 g of the monomer mixture, heat to 50°C, and stir at 200 rpm for 4 h, cool to room temperature, wash with ethanol 3 times, wash with deionized water 5 times, and dry in an oven at 60°C for 15 min to obtain a modifier.

[0062] The reinforcing filler is prepared by the following steps:

[0063] B1. 5.5 g of kaolin and 6.5 g of glucose were added to 60 mL of ethanol, stirred at 70 ° C for 30 min, filtered, washed, dried, and then mixed with 10 mL of 10% potassium hydroxide aqueous solution, stirred evenly, carbonized at 800 ° C for 2 h, cooled to room temperature, taken out, washed with deionized water 3 times, and dried in an oven at 70 ° C for 10 min to obtain modified kaolin;

[0064] B2. Add 1.5 g of itaconic acid and 2 g of phytic acid to 50 mL of deionized water, stir evenly, and react at 65°C with stirring for 30 minutes. Add 5.5 g of modified kaolin and stir evenly. Add 0.2 g of ammonium persulfate and 1.5 g of polyethylene glycol and react at 95°C with stirring for 35 minutes. Cool to room temperature, filter, wash with deionized water three times, and dry in an oven at 70°C for 10 minutes to obtain a reinforced filler.

[0065] Example 3

[0066] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 60 parts of a polybenzimidazole resin, 20 parts of a modifier, 10 parts of a reinforcing filler, 60 parts of a phosphoric acid aqueous solution, and 100 parts of N,N-dimethylacetamide;

[0067] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0068] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 135°C for 3 hours. A modifier, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 300 r / min for 30 minutes. The mixture was decompressed and defoamed by vacuum for 14 hours to obtain a polybenzimidazole resin solution.

[0069] The modifier is prepared by the following steps:

[0070] A1. Add 6 g of 7-hydroxycoumarin to 25 mL of N,N-dimethylacetamide, stir evenly, add 30 mL of triethylamine and 8 mL of methacryloyl chloride, stir at 40°C for 12 h, add 110 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water three times, and dry in an oven at 60°C for 10 min to obtain a coumarin derivative;

[0071] A2. 4 g of eugenol was added to 25 mL of ethanol, stirred evenly, 6 mL of hydroxyethyl methacrylate and 0.4 g of sodium hydroxide were added, and the mixture was stirred at 65 ° C for 10 min, and the mixture was heated to 85 ° C and stirred until the organic solvent evaporated. The solid was taken out, washed with deionized water until the pH of the washing liquid was neutral, and dried in an oven at 60 ° C for 10 min to obtain a eugenol derivative;

[0072] A3. Mix 2.9 g of coumarin derivative and 2.5 g of eugenol derivative, heat at 40°C until completely dissolved to obtain a monomer mixture, mix 2 g of sodium dodecyl sulfate, 1.9 g of sodium bicarbonate, 1.1 g of sodium metabisulfite and 35 mL of deionized water, stir for 30 min, add 5.2 g of the monomer mixture, heat to 55°C, and stir at 200 rpm for 4 h, cool to room temperature, wash with ethanol 3 times, wash with deionized water 5 times, and dry in an oven at 60°C for 15 min to obtain a modifier.

[0073] The reinforcing filler is prepared by the following steps:

[0074] B1. Add 6 g of kaolin and 7 g of glucose to 70 mL of ethanol, stir at 80 ° C for 35 min, filter, wash with deionized water three times, dry in an oven at 70 ° C for 10 min, mix with 12 mL of 10% potassium hydroxide aqueous solution, stir evenly, carbonize at 850 ° C for 3 h, cool to room temperature, take out, wash with deionized water three times, and dry in an oven at 70 ° C for 10 min to obtain modified kaolin;

[0075] B2. Add 2 g of itaconic acid and 3 g of phytic acid to 45 mL of deionized water, stir evenly, and react at 70°C with stirring for 35 minutes. Add 6 g of modified kaolin and stir evenly. Add 0.3 g of ammonium persulfate and 2 g of polyethylene glycol and react at 100°C with stirring for 40 minutes. Cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70°C for 10 minutes to obtain a reinforced filler.

[0076] Comparative Example 1

[0077] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 60 parts of a polybenzimidazole resin, 20 parts of a coumarin derivative, 10 parts of a reinforcing filler, 60 parts of a phosphoric acid aqueous solution, and 100 parts of N,N-dimethylacetamide;

[0078] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0079] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 135°C for 3 hours. A coumarin derivative, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 300 r / min for 30 minutes. The mixture was defoamed by vacuuming for 14 hours to obtain a polybenzimidazole resin solution.

[0080] Coumarin derivatives are prepared by the following steps:

[0081] Add 6 g of 7-hydroxycoumarin to 25 mL of N,N-dimethylacetamide, stir evenly, add 30 mL of triethylamine and 8 mL of methacryloyl chloride, stir at 40 ° C for 12 h, add 110 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water 3 times, and dry in an oven at 60 ° C for 10 min to obtain a coumarin derivative.

[0082] The reinforcing filler is prepared by the following steps:

[0083] B1. Add 6 g of kaolin and 7 g of glucose to 70 mL of ethanol, stir at 80 ° C for 35 min, filter, wash with deionized water three times, dry in an oven at 70 ° C for 10 min, mix with 12 mL of 10% potassium hydroxide aqueous solution, stir evenly, carbonize at 850 ° C for 3 h, cool to room temperature, take out, wash with deionized water three times, and dry in an oven at 70 ° C for 10 min to obtain modified kaolin;

[0084] B2. Add 2 g of itaconic acid and 3 g of phytic acid to 45 mL of deionized water, stir evenly, and react at 70°C with stirring for 35 minutes. Add 6 g of modified kaolin and stir evenly. Add 0.3 g of ammonium persulfate and 2 g of polyethylene glycol and react at 100°C with stirring for 40 minutes. Cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70°C for 10 minutes to obtain a reinforced filler.

[0085] Comparative Example 2

[0086] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 60 parts of a polybenzimidazole resin, 20 parts of a eugenol derivative, 10 parts of a reinforcing filler, 60 parts of a phosphoric acid aqueous solution, and 100 parts of N,N-dimethylacetamide;

[0087] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0088] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 135°C for 3 hours. A eugenol derivative, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 300 r / min for 30 minutes. The mixture was defoamed by vacuuming for 14 hours to obtain a polybenzimidazole resin solution.

[0089] Eugenol derivatives are prepared by the following steps:

[0090] Add 4 g of eugenol to 25 mL of ethanol, stir evenly, add 6 mL of hydroxyethyl methacrylate and 0.4 g of sodium hydroxide, stir and react at 65 ° C for 10 minutes, heat to 85 ° C and stir until the organic solvent evaporates, take out the solid, wash with deionized water until the pH of the washing liquid is neutral, and dry in an oven at 60 ° C for 10 minutes to obtain a eugenol derivative.

[0091] The reinforcing filler is prepared by the following steps:

[0092] B1. Add 6 g of kaolin and 7 g of glucose to 70 mL of ethanol, stir at 80 ° C for 35 min, filter, wash with deionized water three times, dry in an oven at 70 ° C for 10 min, mix with 12 mL of 10% potassium hydroxide aqueous solution, stir evenly, carbonize at 850 ° C for 3 h, cool to room temperature, take out, wash with deionized water three times, and dry in an oven at 70 ° C for 10 min to obtain modified kaolin;

[0093] B2. Add 2 g of itaconic acid and 3 g of phytic acid to 45 mL of deionized water, stir evenly, and react at 70°C with stirring for 35 minutes. Add 6 g of modified kaolin and stir evenly. Add 0.3 g of ammonium persulfate and 2 g of polyethylene glycol and react at 100°C with stirring for 40 minutes. Cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70°C for 10 minutes to obtain a reinforced filler.

[0094] Comparative Example 3

[0095] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 60 parts of a polybenzimidazole resin, 20 parts of a modifier, 10 parts of a reinforcing filler, 60 parts of a phosphoric acid aqueous solution, and 100 parts of N,N-dimethylacetamide;

[0096] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0097] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 135°C for 3 hours. A modifier, a phosphoric acid aqueous solution and a reinforcing filler were added, and the mixture was stirred at 300 r / min for 30 minutes. The mixture was decompressed and defoamed by vacuum for 14 hours to obtain a polybenzimidazole resin solution.

[0098] The modifier is prepared by the following steps:

[0099] A1. Add 6 g of 7-hydroxycoumarin to 25 mL of N,N-dimethylacetamide, stir evenly, add 30 mL of triethylamine and 8 mL of methacryloyl chloride, stir at 40°C for 12 h, add 110 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water three times, and dry in an oven at 60°C for 10 min to obtain a coumarin derivative;

[0100] A2. 4 g of eugenol was added to 25 mL of ethanol, stirred evenly, 6 mL of hydroxyethyl methacrylate and 0.4 g of sodium hydroxide were added, and the mixture was stirred at 65 ° C for 10 min, and the mixture was heated to 85 ° C and stirred until the organic solvent evaporated. The solid was taken out, washed with deionized water until the pH of the washing liquid was neutral, and dried in an oven at 60 ° C for 10 min to obtain a eugenol derivative;

[0101] A3. Mix 2.9 g of coumarin derivative and 2.5 g of eugenol derivative, heat at 40°C until completely dissolved to obtain a monomer mixture, mix 2 g of sodium dodecyl sulfate, 1.9 g of sodium bicarbonate, 1.1 g of sodium metabisulfite and 35 mL of deionized water, stir for 30 min, add 5.2 g of the monomer mixture, heat to 55°C, and stir at 200 rpm for 4 h, cool to room temperature, wash with ethanol 3 times, wash with deionized water 5 times, and dry in an oven at 60°C for 15 min to obtain a modifier.

[0102] The reinforcing filler is prepared by the following steps:

[0103] Add 2 g of itaconic acid and 3 g of phytic acid to 45 mL of deionized water, stir evenly, and react at 70°C with stirring for 35 minutes. Add 6 g of kaolin and stir evenly. Add 0.3 g of ammonium persulfate and 2 g of polyethylene glycol, and react at 100°C with stirring for 40 minutes. Cool to room temperature, filter, wash with deionized water 3 times, and dry in an oven at 70°C for 10 minutes to obtain a reinforced filler.

[0104] Comparative Example 4

[0105] A polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following raw materials in parts by weight: 60 parts of a polybenzimidazole resin, 20 parts of a modifier, 10 parts of modified kaolin, 60 parts of a phosphoric acid aqueous solution, and 100 parts of N,N-dimethylacetamide;

[0106] A method for preparing a polybenzimidazole resin solution suitable for a proton exchange membrane comprises the following preparation steps:

[0107] The polybenzimidazole resin was added to N,N-dimethylacetamide, and the mixture was stirred at 135°C for 3 hours. A modifier, a phosphoric acid aqueous solution and modified kaolin were added, and the mixture was stirred at 300 r / min for 30 minutes. The mixture was defoamed by vacuuming for 14 hours to obtain a polybenzimidazole resin solution.

[0108] The modifier is prepared by the following steps:

[0109] A1. Add 6 g of 7-hydroxycoumarin to 25 mL of N,N-dimethylacetamide, stir evenly, add 30 mL of triethylamine and 8 mL of methacryloyl chloride, stir at 40°C for 12 h, add 110 mL of methanol to remove excess methacryloyl chloride, distill under reduced pressure until crystals precipitate, filter, wash with deionized water three times, and dry in an oven at 60°C for 10 min to obtain a coumarin derivative;

[0110] A2. 4 g of eugenol was added to 25 mL of ethanol, stirred evenly, 6 mL of hydroxyethyl methacrylate and 0.4 g of sodium hydroxide were added, and the mixture was stirred at 65 ° C for 10 min, and the mixture was heated to 85 ° C and stirred until the organic solvent evaporated. The solid was taken out, washed with deionized water until the pH of the washing liquid was neutral, and dried in an oven at 60 ° C for 10 min to obtain a eugenol derivative;

[0111] A3. Mix 2.9 g of coumarin derivative and 2.5 g of eugenol derivative, heat at 40°C until completely dissolved to obtain a monomer mixture, mix 2 g of sodium dodecyl sulfate, 1.9 g of sodium bicarbonate, 1.1 g of sodium metabisulfite and 35 mL of deionized water, stir for 30 min, add 5.2 g of the monomer mixture, heat to 55°C, and stir at 200 rpm for 4 h, cool to room temperature, wash with ethanol 3 times, wash with deionized water 5 times, and dry in an oven at 60°C for 15 min to obtain a modifier.

[0112] The reinforcing filler is prepared by the following steps:

[0113] Add 6 g of kaolin and 7 g of glucose to 70 mL of ethanol, stir at 80 ° C for 35 minutes, filter, wash with deionized water three times, dry in an oven at 70 ° C for 10 minutes, mix with 12 mL of 10% potassium hydroxide aqueous solution, stir evenly, carbonize at 850 ° C for 3 hours, cool to room temperature, take out, wash with deionized water three times, and dry in an oven at 70 ° C for 10 minutes to obtain modified kaolin.

[0114] The performance of the polybenzimidazole resin solutions prepared in Examples 1-3 and Comparative Examples 1-4 was tested.

[0115] The polybenzimidazole resin solution prepared above was placed on a glass plate, kept at 120° C. for 2 hours, scraped, and then dried in an oven at 80° C. for 12 hours to obtain a polybenzimidazole resin proton exchange membrane;

[0116] Mechanical property testing: The tensile strength and flexural strength of the polybenzimidazole resin film prepared above were tested according to GB / T 1040-2006 standard;

[0117] Solubility test: The viscosity of the polybenzimidazole resin solution prepared above was measured using a viscosity meter;

[0118] Heat resistance test: The heat resistance of the polybenzimidazole resin solution prepared above was measured by thermogravimetric analysis;

[0119] The proton conductivity of the proton exchange membrane was tested using the AutolabPGSTAT302N electrochemical workstation, and its proton conductivity was analyzed by the proton conductivity of the proton exchange membrane. The specific test steps for the proton conductivity are as follows: a 5 cm × 1 cm polybenzimidazole resin proton exchange membrane was fixed on the electrode fixture of the electrochemical workstation, and the impedance value of the membrane was tested using the four-electrode method at 150°C. The proton conductivity of the proton exchange membrane was calculated, and the proton conductivity = the distance between the two electrodes / (cross-sectional area of ​​the membrane × impedance of the membrane).

[0120] The test results are shown in Table 1 below.

[0121] Table 1 Performance test of polybenzimidazole resin solution prepared in Examples 1-3 and Comparative Examples 1-4

[0122]

[0123]

[0124] It can be seen from the data in Table 1 that the polybenzimidazole resin solutions prepared in Examples 1-3 have good solubility and mechanical properties, and the formed proton exchange membranes have high proton conductivity.

[0125] In Comparative Example 1, the modifier was replaced with a coumarin derivative and added to the polybenzimidazole resin solution. Its solubility and mechanical properties decreased, and the proton conductivity of the formed proton exchange membrane decreased, proving that the coumarin derivative and the eugenol derivative copolymerized to form a stable polymer emulsion. As a modifier, it contains a large amount of flexible long chains and can give the polybenzimidazole resin better flexibility.

[0126] In Comparative Example 2, the modifier was replaced with a eugenol derivative and added to the polybenzimidazole resin solution. Its wound repair property decreased, and the proton conductivity of the formed proton exchange membrane decreased, proving that the benzene ring structure on the molecular chain of the stable polymer emulsion formed by copolymerization of coumarin derivatives and eugenol derivatives can interact with the benzene ring on the polybenzimidazole resin molecular chain, and can weaken the hydrogen bonds between the polybenzimidazole resin molecular chains, thereby improving the solubility performance of the polybenzimidazole resin.

[0127] In Comparative Example 3, the modified kaolin is replaced with a reinforcing filler prepared from kaolin and added to the polybenzimidazole resin solution. Its solubility, heat resistance and mechanical properties decrease, and the proton conductivity of the formed proton exchange membrane decreases, indicating that porous carbon is synthesized on the surface of kaolin. The large specific surface area and pore capacity of the porous carbon can act as a lubricating component, which is beneficial to the movement of the polybenzimidazole resin molecular chains and improves the fluidity of the polybenzimidazole resin solution.

[0128] In Comparative Example 4, the reinforcing filler was replaced with modified kaolin and added to the polybenzimidazole resin solution. Its solubility, heat resistance and mechanical properties decreased, and the proton conductivity of the formed proton exchange membrane decreased, proving that the polymer formed by itaconic acid and phytic acid has higher mechanical properties, and itaconic acid and phytic acid can further improve the high temperature resistance of polybenzimidazole resin.

[0129] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0130] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A polybenzimidazole resin solution suitable for proton exchange membrane, characterized in that: The method comprises the following raw materials in parts by weight: 50-60 parts of polybenzimidazole resin, 10-20 parts of modifier, 5-10 parts of reinforcing filler, 50-60 parts of phosphoric acid solution, and 80-100 parts of solvent; The modifier is obtained by mixing a coumarin derivative and a eugenol derivative and then performing emulsion copolymerization; The reinforcing filler is prepared by mixing kaolin and glucose, carbonizing them at high temperature, and then mixing and reacting with itaconic acid and phytic acid.

2. A polybenzimidazole resin solution suitable for proton exchange membrane according to claim 1, characterized in that: The modifying agent is prepared by the following steps: A1. Add 7-hydroxycoumarin to N,N-dimethylacetamide, stir evenly, add triethylamine and methacryloyl chloride, stir at 30-40°C for 10-12h, add methanol, distill under reduced pressure, filter, wash and dry to obtain a coumarin derivative; A2. Eugenol was added to ethanol, stirred evenly, hydroxyethyl methacrylate and sodium hydroxide were added, and the reaction was stirred until the organic solvent evaporated, the solid was removed, washed, and dried to obtain a eugenol derivative; A3. Mix the coumarin derivative and the eugenol derivative, stir until dissolved to obtain a monomer mixture, mix sodium dodecyl sulfate, sodium bicarbonate, sodium metabisulfite and deionized water, stir evenly, add the monomer mixture, heat to 45-55°C, stir and react after completion, cool to room temperature, wash and dry to obtain a modifier.

3. A polybenzimidazole resin solution suitable for proton exchange membrane according to claim 2, characterized in that: In step A1, the amount ratio of 7-hydroxycoumarin, 50-60 parts of phosphoric acid aqueous solution, N,N-dimethylacetamide, triethylamine, methacryloyl chloride, and methanol is (4-6) g: (15-25) mL: (20-30) mL: (7-8) mL: (90-110) mL.

4. A polybenzimidazole resin solution suitable for proton exchange membrane according to claim 2, characterized in that: In step A2, the ratio of eugenol, ethanol, hydroxyethyl methacrylate and sodium hydroxide is (3-4) g: (15-25) mL: (4-6) mL: (0.2-0.4) g.

5. A polybenzimidazole resin solution suitable for proton exchange membrane according to claim 2, characterized in that: In step A3, the mass ratio of the coumarin derivative to the eugenol derivative is (2.5-2.9):(2.3-2.5); The dosage ratio of the sodium dodecyl sulfate, sodium bicarbonate, sodium pyrosulfite, deionized water and monomer mixture is (1.6-2) g: (1.5-1.9) g: (0.8-1.1) g: (25-35) mL: (5-5.2) g.

6. The polybenzimidazole resin solution suitable for proton exchange membrane according to claim 1, characterized in that: The reinforcing filler is prepared by the following steps: B1. Add kaolin and glucose to ethanol, stir at 60-80°C for 25-35min, filter, wash, dry, mix with potassium hydroxide aqueous solution, stir evenly, carbonize at 750-850°C for 1-3h, cool to room temperature, take out, wash, and dry to obtain modified kaolin; B2. Add itaconic acid and phytic acid to deionized water, stir evenly, react at 60-70°C for 25-35 minutes, add modified kaolin, stir evenly, add ammonium persulfate and polyethylene glycol, react at 90-100°C for 30-40 minutes, cool to room temperature, filter, wash and dry to obtain a reinforced filler.

7. A polybenzimidazole resin solution suitable for proton exchange membrane according to claim 6, characterized in that: In step B1, the ratio of kaolin, glucose, ethanol and potassium hydroxide aqueous solution is (5-6) g: (6-7) g: (50-70) mL: (8-12) mL.

8. The polybenzimidazole resin solution suitable for proton exchange membrane according to claim 6, characterized in that: In step B2, the usage ratio of itaconic acid, phytic acid, deionized water, modified kaolin, ammonium persulfate and polyethylene glycol is (1-2) g: (1-3) g: (45-55) mL: (5-6) g: (0.1-0.3) g: (1-2) g.

9. A method for preparing a polybenzimidazole resin solution according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: Add polybenzimidazole resin to the solvent, rotate and stir at 125-135° C. for 1-3 hours, add modifier, phosphoric acid solution and reinforcing filler, stir at 200-300 r / min for 20-30 minutes, and degas by vacuum decompression for 10-14 hours to obtain a polybenzimidazole resin solution.

Images