A kind of adsorbent for purifying diethyltoluenediamine and its preparation method and application method

Abstract

The invention provides an adsorbent for purifying diethyltoluenediamine and a preparation method and an application method thereof, and belongs to the technical field of chemical industry. The adsorbent is loaded into a column, the prepared diethyltoluenediamine product is added, eluted, the eluate is collected, and the solvent is removed under reduced pressure to obtain diethyltoluenediamine. The method of the invention can better separate and purify diethyltoluenediamine with high selectivity, and the obtained diethyltoluenediamine has high purity and few impurities, and has broad application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to an adsorbent for purifying diethyltoluenediamine and a preparation method and an application method thereof. Background Art

[0002] Amine chain extenders are divided into two categories: aliphatic amines and aromatic amines. 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) once dominated the aromatic amine chain extenders. Although the resulting product has good mechanical properties, the latest clinical findings show that 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) has certain carcinogenicity and is harmful to people's physical and mental health. Some European and American countries have strictly restricted its use. The development of new environmentally friendly aromatic amine chain extenders has gradually become an urgent task for the modern chemical industry.

[0003] Diethyltoluenediamine (DETDA) is a light yellow to amber transparent viscous liquid with a slight ammonia smell. It is slightly soluble in water, soluble in polar organic solvents such as alcohol, ether, and ketone, and has good compatibility with polyether and polyester polyols. Diethyltoluenediamine has low viscosity, uniform dispersion, and high chemical activity. It can be used directly as a chain extender, and the reaction is relatively thorough. Comprehensive investigation has found no harm to human health. It is an ideal substitute for 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA). Diethyltoluenediamine has the advantages of short demoulding time, high initial strength, and hydrolysis resistance and heat resistance of the product. It is mainly used as a curing agent, chain extender, polyurethane raw material, amine catalyst, lubricant, antioxidant for industrial oils and fats, and chemical synthesis intermediates.

[0004] Diethyltoluenediamine is prepared by alkylating toluenediamine (TDA) with olefins under high temperature, high pressure and in the presence of a catalyst. Usually, the reaction product is doped with unreacted toluenediamine and other alkyltoluenediamines, so the product needs to be purified to obtain high-purity diethyltoluenediamine. Summary of the invention

[0005] The purpose of the present invention is to provide an adsorbent for purifying diethyltoluenediamine and a preparation method and an application method thereof, which can separate and purify diethyltoluenediamine with good high selectivity, and the obtained diethyltoluenediamine has high purity and few impurities, and has broad application prospects.

[0006] The technical solution of the present invention is achieved in this way:

[0007] The present invention provides a method for preparing an adsorbent for purifying diethyltoluenediamine, comprising the following steps:

[0008] S1. Preparation of modified molecular sieve: adding water glass to water, adding pyrrolidine, stirring and mixing to obtain solution 1; adding aluminum sulfate to water, adding concentrated sulfuric acid, stirring and mixing to obtain solution 2; adding solution 2 dropwise to solution 1, heating and stirring to react, adding alkyl orthosilicate and porogen, transferring to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heating and crystallizing, cooling to room temperature, filtering, washing, drying, and calcining to obtain a modified molecular sieve;

[0009] S2 dealumination: preparing an acid solution, adding a modified molecular sieve, heating and stirring the reaction, filtering, washing, drying, and calcining to obtain a dealumination modified molecular sieve;

[0010] S3 metal ion modification: the dealuminated molecular sieve is added to water, a metal ion salt is added, the reaction is heated and stirred, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve;

[0011] S4. Polymer modification: mixing a metal ion-modified dealuminized molecular sieve, diethyltoluenediamine, a functional monomer, a crosslinking agent, and a porogen, adding an initiator under inert gas protection, heating the polymerization reaction, filtering, and drying to obtain a polymer-modified molecular sieve;

[0012] S5. Preparation of adsorbent: Add the polymer-modified molecular sieve into a Soxhlet extractor, elute with an eluent until diethyltoluenediamine is undetectable, wash, and dry to obtain an adsorbent for purification of diethyltoluenediamine.

[0013] As a further improvement of the present invention, the mass ratio of water glass, pyrrolidine, aluminum sulfate, concentrated sulfuric acid, alkyl orthosilicate and porogen in step S1 is 12-15:2-4:7-9:1-3:3-5:0.1-0.2, the temperature of the heating and stirring reaction is 35-45°C, the time is 20-24h, the temperature of the heating crystallization is 130-140°C, the time is 56-72h, the temperature of the calcination is 500-600°C, the time is 4-6h, and the porogen is a polyoxyethylene-polyoxypropylene triblock copolymer PEO20-PPO70-PEO20 (P123) or PEO106-PPO70-PEO106.

[0014] As a further improvement of the present invention, the acid solution in step S2 is a mixed solution of 1-2 mol / L hydrochloric acid and 0.5-1 mol / L sulfuric acid, the temperature of the heating and stirring reaction is 75-85°C, the time is 3-5h, and the calcination temperature is 500-600°C, and the time is 4-6h.

[0015] As a further improvement of the present invention, the mass ratio of the dealuminated modified molecular sieve and the metal ion salt in step S3 is 100:3-6, the metal ion salt includes strontium chloride and barium chloride in a mass ratio of 3-5:10, the temperature of the heating and stirring reaction is 60-80°C, and the time is 3-5h.

[0016] As a further improvement of the present invention, the mass ratio of the metal ion modified dealuminated molecular sieve, diethyltoluenediamine, functional monomer, cross-linking agent, porogen and initiator in step S4 is 100:5-7:22-25:0.5-0.7:2-3:0.1-0.2, the initiator is selected from at least one of sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile, azobisisoheptanenitrile and benzoyl peroxide, the functional monomer includes 4-vinylpyridine and butyl methacrylate in a mass ratio of 7-10:2-4, the cross-linking agent is ethylene glycol dimethacrylate, the porogen is acetone, the temperature of the heating polymerization reaction is 50-60°C, and the time is 1-3h.

[0017] As a further improvement of the present invention, the eluent used for elution in step S5 is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1-2.

[0018] As a further improvement of the present invention, the preparation method comprises the following steps:

[0019] S1. Preparation of modified molecular sieve: Add 12-15 parts by weight of water glass to water, add 2-4 parts by weight of pyrrolidine, stir and mix evenly to obtain solution 1; add 7-9 parts by weight of aluminum sulfate to water, add 1-3 parts by weight of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 35-45°C, stir and react for 20-24h, add 3-5 parts by weight of alkyl orthosilicate and 0.1-0.2 parts by weight of porogen, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 130-140°C, crystallize for 56-72h, cool to room temperature, filter, wash, dry, and calcine at 500-600°C for 4-6h to obtain a modified molecular sieve;

[0020] S2. Dealumination: prepare an acid solution, add the modified molecular sieve, heat to 75-85°C, stir and react for 3-5h, filter, wash with boiling water, dry, and calcine at 500-600°C for 4-6h to obtain a dealumination modified molecular sieve;

[0021] The acid solution is a mixed solution of 1-2 mol / L hydrochloric acid and 0.5-1 mol / L sulfuric acid;

[0022] S3 metal ion modification: 100 parts by weight of dealuminated molecular sieve was added to water, 3-6 parts by weight of metal ion salt was added, heated to 60-80 ° C, stirred for 3-5h, filtered, washed and dried to obtain a metal ion modified dealuminated molecular sieve;

[0023] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 3-5:10;

[0024] S4. Polymer modification: 100 parts by weight of a metal ion-modified dealuminated molecular sieve, 5-7 parts by weight of diethyltoluenediamine, 22-25 parts by weight of a functional monomer, 0.5-0.7 parts by weight of a crosslinking agent, and 2-3 parts by weight of a porogen are mixed, and under the protection of an inert gas, 0.1-0.2 parts by weight of an initiator is added, heated to 50-60° C., polymerized for 1-3 hours, filtered, and dried to obtain a polymer-modified molecular sieve;

[0025] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 7-10:2-4;

[0026] S5. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0027] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1-2.

[0028] The present invention further protects an adsorbent for purifying diethyltoluenediamine obtained by the above-mentioned preparation method.

[0029] The present invention further protects an application method of the above-mentioned adsorbent for purifying diethyltoluenediamine, which comprises loading the adsorbent into a column, adding the prepared diethyltoluenediamine product, eluting, collecting the eluate, and removing the solvent under reduced pressure to obtain diethyltoluenediamine.

[0030] As a further improvement of the present invention, the eluent used for elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1-2.

[0031] The present invention has the following beneficial effects:

[0032] The present invention adopts a hydrothermal synthesis method to prepare a molecular sieve. The special Zig-Zag type pore structure makes it have excellent shape selectivity, but also increases the diffusion resistance of the molecular sieve, so that it has a better separation and purification effect on the prepared diethyltoluenediamine product. However, there are problems such as low separation selectivity and low mechanical strength.

[0033] Therefore, in the present invention, ethyl orthosilicate is added to the molecular sieve for catalytic hydrolysis modification during the preparation process of the molecular sieve, and coated on the surface of the molecular sieve, thereby improving the mechanical strength of the molecular sieve and forming pores under the action of the porogen, which plays a good separation and purification role and can effectively remove the raw material toluenediamine. However, the selectivity for diethyltoluenediamine is poor.

[0034] The present invention uses acid to dealuminate the molecular sieve and uses metal ions strontium and barium for ion exchange, so that the pore size of the molecular sieve is appropriate and other impurities can be effectively removed. However, it is still difficult to efficiently remove diethyltoluenediamine and other alkyltoluenediamines.

[0035] Therefore, the present invention uses diethyltoluenediamine as a template agent, continues to generate a polymer in situ on the basis of an inorganic metal ion-modified dealuminized molecular sieve, and forms a molecular sieve modified with a molecular imprinting polymer after the template agent is removed by an eluent. The molecular sieve, which is used as an adsorbent, can better separate and purify diethyltoluenediamine with high selectivity. The obtained diethyltoluenediamine has high purity and few impurities, and has broad application prospects. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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. Example 1

[0037] The preparation method of the adsorbent for purifying diethyltoluenediamine comprises the following steps:

[0038] S1. Preparation of modified molecular sieve: Add 12g of water glass to 500mL of water, add 2g of pyrrolidine, stir and mix evenly to obtain solution 1; add 7g of aluminum sulfate to 200mL of water, add 1g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 35°C, stir and react for 20h, add 3g of methyl orthosilicate and 0.1g of polyoxyethylene-polyoxypropylene triblock copolymer PEO20-PPO70-PEO20 (P123), transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 130°C, crystallize for 56h, cool to room temperature, filter, wash, dry, and calcine at 500°C for 4h to obtain a modified molecular sieve;

[0039] S2. Dealumination: Prepare 500mL of acid solution, add 100g of modified molecular sieve, heat to 75°C, stir and react for 3h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 500°C for 4h to obtain a dealumination modified molecular sieve;

[0040] The acid solution is a mixed solution of 1 mol / L hydrochloric acid and 0.5 mol / L sulfuric acid;

[0041] S3. Metal ion modification: 100 g of dealuminated molecular sieve was added to 500 mL of water, 3 g of metal ion salt was added, heated to 60 ° C, stirred for 3 h, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve;

[0042] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 3:10;

[0043] S4. Polymer modification: 100 g of metal ion modified dealuminated molecular sieve, 5 g of diethyltoluenediamine, 22 g of functional monomer, 0.5 g of ethylene glycol dimethacrylate, and 2 g of acetone were mixed in 200 mL of acetonitrile, 0.1 g of benzoyl peroxide was added under nitrogen protection, and the mixture was heated to 50 ° C. The polymerization reaction was carried out for 1 h, filtered, and dried to obtain a polymer modified molecular sieve;

[0044] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 7:2;

[0045] S5. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0046] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1. Example 2

[0047] The preparation method of the adsorbent for purifying diethyltoluenediamine comprises the following steps:

[0048] S1. Preparation of modified molecular sieve: Add 15g of water glass to 500mL of water, add 4g of pyrrolidine, stir and mix evenly to obtain solution 1; add 9g of aluminum sulfate to 200mL of water, add 3g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 45°C, stir and react for 24h, add 5g of tetraethyl orthosilicate and 0.2g of polyoxyethylene-polyoxypropylene triblock copolymer PEO20-PPO70-PEO20 (P123), transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 140°C, crystallize for 72h, cool to room temperature, filter, wash, dry, and calcine at 600°C for 6h to obtain a modified molecular sieve;

[0049] S2. Dealumination: Prepare 500 mL of acid solution, add 100 g of modified molecular sieve, heat to 85 ° C, stir and react for 5 h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 600 ° C for 6 h to obtain a dealumination modified molecular sieve;

[0050] The acid solution is a mixed solution of 2 mol / L hydrochloric acid and 1 mol / L sulfuric acid;

[0051] S3. Metal ion modification: 100 g of dealuminated molecular sieve was added to 500 mL of water, 6 g of metal ion salt was added, heated to 80 ° C, stirred for 5 h, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve;

[0052] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 5:10;

[0053] S4. Polymer modification: 100 g of metal ion modified dealuminated molecular sieve, 7 g of diethyltoluenediamine, 25 g of functional monomer, 0.7 g of ethylene glycol dimethacrylate, and 3 g of acetone were mixed in 200 mL of acetonitrile, and 0.2 g of azobisisoheptanenitrile was added under nitrogen protection, and the mixture was heated to 60 ° C. The polymerization reaction was carried out for 3 h, filtered, and dried to obtain a polymer modified molecular sieve;

[0054] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 10:4;

[0055] S5. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0056] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:2. Example 3

[0057] The preparation method of the adsorbent for purifying diethyltoluenediamine comprises the following steps:

[0058] S1. Preparation of modified molecular sieve: Add 13.5g of water glass to 500mL of water, add 3g of pyrrolidine, stir and mix evenly to obtain solution 1; add 8g of aluminum sulfate to 200mL of water, add 2g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 40°C, stir and react for 22h, add 4g of tetraethyl orthosilicate and 0.15g of PEO106-PPO70-PEO106, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 135°C, crystallize for 64h, cool to room temperature, filter, wash, dry, and calcine at 550°C for 5h to obtain a modified molecular sieve;

[0059] S2. Dealumination: Prepare 500mL of acid solution, add 100g of modified molecular sieve, heat to 80°C, stir and react for 4h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 550°C for 5h to obtain dealumination modified molecular sieve;

[0060] The acid solution is a mixed solution of 1.5 mol / L hydrochloric acid and 0.7 mol / L sulfuric acid;

[0061] S3. Metal ion modification: 100 g of dealuminated molecular sieve was added to 500 mL of water, 4.5 g of metal ion salt was added, heated to 70 ° C, stirred for 4 h, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve;

[0062] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 4:10;

[0063] S4. Polymer modification: 100 g of metal ion modified dealuminated molecular sieve, 6 g of diethyltoluenediamine, 23.5 g of functional monomer, 0.6 g of ethylene glycol dimethacrylate, and 2.5 g of acetone were mixed in 200 mL of acetonitrile, and 0.15 g of azobisisobutyronitrile was added under nitrogen protection. The mixture was heated to 55 ° C. The polymerization reaction was carried out for 2 h. The mixture was filtered and dried to obtain a polymer modified molecular sieve.

[0064] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 8:3;

[0065] S5. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0066] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1.5.

[0067] Comparative Example 1

[0068] Compared with Example 3, the difference is that tetraethyl orthosilicate is not added in step S1.

[0069] The details are as follows:

[0070] S1. Preparation of modified molecular sieve: Add 13.5g of water glass to 500mL of water, add 3g of pyrrolidine, stir and mix evenly to obtain solution 1; add 8g of aluminum sulfate to 200mL of water, add 2g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 40°C, stir and react for 22h, add 0.15g of PEO106-PPO70-PEO106, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 135°C, crystallize for 64h, cool to room temperature, filter, wash, dry, and calcine at 550°C for 5h to obtain a modified molecular sieve;

[0071] S2. Dealumination: Prepare 500mL of acid solution, add 100g of modified molecular sieve, heat to 80°C, stir and react for 4h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 550°C for 5h to obtain dealumination modified molecular sieve;

[0072] The acid solution is a mixed solution of 1.5 mol / L hydrochloric acid and 0.7 mol / L sulfuric acid;

[0073] S3. Metal ion modification: 100 g of dealuminated molecular sieve was added to 500 mL of water, 4.5 g of metal ion salt was added, heated to 70 ° C, stirred for 4 h, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve;

[0074] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 4:10;

[0075] S4. Polymer modification: 100 g of metal ion modified dealuminated molecular sieve, 6 g of diethyltoluenediamine, 23.5 g of functional monomer, 0.6 g of ethylene glycol dimethacrylate, and 2.5 g of acetone were mixed in 200 mL of acetonitrile, and 0.15 g of azobisisobutyronitrile was added under nitrogen protection. The mixture was heated to 55 ° C. The polymerization reaction was carried out for 2 h. The mixture was filtered and dried to obtain a polymer modified molecular sieve.

[0076] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 8:3;

[0077] S5. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0078] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1.5.

[0079] Comparative Example 2

[0080] Compared with Example 3, the difference is that step S2 is not performed.

[0081] The details are as follows:

[0082] S1. Preparation of modified molecular sieve: Add 13.5g of water glass to 500mL of water, add 3g of pyrrolidine, stir and mix evenly to obtain solution 1; add 8g of aluminum sulfate to 200mL of water, add 2g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 40°C, stir and react for 22h, add 4g of tetraethyl orthosilicate and 0.15g of PEO106-PPO70-PEO106, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 135°C, crystallize for 64h, cool to room temperature, filter, wash, dry, and calcine at 550°C for 5h to obtain a modified molecular sieve;

[0083] S2. Metal ion modification: 100 g of modified molecular sieve was added to 500 mL of water, 4.5 g of metal ion salt was added, heated to 70 ° C, stirred for 4 h, filtered, washed, and dried to obtain a metal ion modified molecular sieve;

[0084] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 4:10;

[0085] S3. Polymer modification: 100 g of metal ion modified molecular sieve, 6 g of diethyltoluenediamine, 23.5 g of functional monomer, 0.6 g of ethylene glycol dimethacrylate, and 2.5 g of acetone were mixed in 200 mL of acetonitrile, 0.15 g of azobisisobutyronitrile was added under nitrogen protection, heated to 55 ° C, polymerized for 2 h, filtered, and dried to obtain a polymer modified molecular sieve;

[0086] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 8:3;

[0087] S4. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0088] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1.5.

[0089] Comparative Example 3

[0090] Compared with Example 3, the difference is that step S3 is not performed.

[0091] The details are as follows:

[0092] S1. Preparation of modified molecular sieve: Add 13.5g of water glass to 500mL of water, add 3g of pyrrolidine, stir and mix evenly to obtain solution 1; add 8g of aluminum sulfate to 200mL of water, add 2g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 40°C, stir and react for 22h, add 4g of tetraethyl orthosilicate and 0.15g of PEO106-PPO70-PEO106, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 135°C, crystallize for 64h, cool to room temperature, filter, wash, dry, and calcine at 550°C for 5h to obtain a modified molecular sieve;

[0093] S2. Dealumination: Prepare 500mL of acid solution, add 100g of modified molecular sieve, heat to 80°C, stir and react for 4h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 550°C for 5h to obtain dealumination modified molecular sieve;

[0094] The acid solution is a mixed solution of 1.5 mol / L hydrochloric acid and 0.7 mol / L sulfuric acid;

[0095] S3. Polymer modification: 100 g of dealuminated molecular sieve, 6 g of diethyltoluenediamine, 23.5 g of functional monomer, 0.6 g of ethylene glycol dimethacrylate, and 2.5 g of acetone were mixed in 200 mL of acetonitrile, 0.15 g of azobisisobutyronitrile was added under nitrogen protection, and the mixture was heated to 55 ° C. The polymerization reaction was carried out for 2 h, filtered, and dried to obtain a polymer-modified molecular sieve;

[0096] The functional monomers include 4-vinylpyridine and butyl methacrylate in a mass ratio of 8:3;

[0097] S4. Preparation of adsorbent: adding the polymer-modified molecular sieve to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine;

[0098] The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1.5.

[0099] Comparative Example 4

[0100] Compared with Example 3, the difference is that steps S4 and S5 are not performed.

[0101] The details are as follows:

[0102] S1. Preparation of modified molecular sieve: Add 13.5g of water glass to 500mL of water, add 3g of pyrrolidine, stir and mix evenly to obtain solution 1; add 8g of aluminum sulfate to 200mL of water, add 2g of concentrated sulfuric acid, stir and mix evenly to obtain solution 2; add solution 2 dropwise to solution 1, heat to 40°C, stir and react for 22h, add 4g of tetraethyl orthosilicate and 0.15g of PEO106-PPO70-PEO106, transfer to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heat to 135°C, crystallize for 64h, cool to room temperature, filter, wash, dry, and calcine at 550°C for 5h to obtain a modified molecular sieve;

[0103] S2. Dealumination: Prepare 500mL of acid solution, add 100g of modified molecular sieve, heat to 80°C, stir and react for 4h, filter, wash with boiling water until the washing liquid is the center, dry, and calcine at 550°C for 5h to obtain dealumination modified molecular sieve;

[0104] The acid solution is a mixed solution of 1.5 mol / L hydrochloric acid and 0.7 mol / L sulfuric acid;

[0105] S3. Metal ion modification: 100 g of dealuminated molecular sieve was added to 500 mL of water, 4.5 g of metal ion salt was added, the mixture was heated to 70 ° C, stirred for 4 h, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve, which is an adsorbent;

[0106] The metal ion salt includes strontium chloride and barium chloride in a mass ratio of 4:10.

[0107] Test Example 1

[0108] The specific surface area and total pore volume of the adsorbents prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were measured using a 3-FLEX 3500 multi-station high-throughput gas adsorption instrument. The compressive strength test was performed using a LJ 5000 compression tester with a measuring range of 0-5000N.

[0109] The results are shown in Table 1.

[0110] Table 1 ;

[0111] It can be seen from the above table that the adsorbents prepared in Examples 1-3 of the present invention have large specific surface areas and total pore volumes, and high compressive strength. Example 4

[0112] Under nitrogen protection, toluenediamine and catalyst aluminum chloride were evenly mixed, the amount of catalyst added was 2wt% of toluenediamine, the temperature was raised to 115°C, ethylene was introduced, heated to 195°C, pressurized to 1.5MPa, reacted for 2h, and the product was collected at a vacuum degree of 0.95MPa and a temperature of 180°C. The distillation components were diethyltoluenediamine products.

[0113] The adsorbent prepared in Example 1 was loaded into a column, and the prepared diethyltoluenediamine product was added thereto for elution. The eluent was collected and the solvent was removed under reduced pressure to obtain diethyltoluenediamine. The eluent used for the elution was a dichloromethane-ethyl acetate mixture in a volume ratio of 10:1. Example 5

[0114] Under nitrogen protection, toluenediamine and catalyst aluminum chloride were evenly mixed, the amount of catalyst added was 2wt% of toluenediamine, the temperature was raised to 115°C, ethylene was introduced, heated to 195°C, pressurized to 1.5MPa, reacted for 2h, and the product was collected at a vacuum degree of 0.95MPa and a temperature of 180°C. The distillation components were diethyltoluenediamine products.

[0115] The adsorbent prepared in Example 2 was loaded into a column, and the prepared diethyltoluenediamine product was added thereto for elution. The eluent was collected and the solvent was removed under reduced pressure to obtain diethyltoluenediamine. The eluent used for the elution was a mixture of dichloromethane and ethyl acetate in a volume ratio of 10:2. Example 6

[0116] Under nitrogen protection, toluenediamine and catalyst aluminum chloride were evenly mixed, the amount of catalyst added was 2wt% of toluenediamine, the temperature was raised to 115°C, ethylene was introduced, heated to 195°C, pressurized to 1.5MPa, reacted for 2h, and the product was collected at a vacuum degree of 0.95MPa and a temperature of 180°C. The distillation components were diethyltoluenediamine products.

[0117] The adsorbent prepared in Example 3 was loaded into a column, and the prepared diethyltoluenediamine product was added thereto for elution. The eluent was collected and the solvent was removed under reduced pressure to obtain diethyltoluenediamine. The eluent used for the elution was a mixture of dichloromethane and ethyl acetate in a volume ratio of 10:1.5.

[0118] Comparative Examples 5-8

[0119] Compared with Example 6, the difference is that the adsorbent is prepared from Comparative Examples 1-4.

[0120] Comparative Example 9

[0121] Compared with Example 6, the difference is that no adsorbent purification is performed.

[0122] The details are as follows:

[0123] Under nitrogen protection, toluenediamine and catalyst aluminum chloride were evenly mixed, the amount of catalyst added was 2wt% of toluenediamine, the temperature was raised to 115°C, ethylene was introduced, heated to 195°C, pressurized to 1.5MPa, reacted for 2h, and the product was collected at a vacuum degree of 0.95MPa and a temperature of 180°C. The distillation components were diethyltoluenediamine.

[0124] Test Example 1

[0125] The products obtained in Examples 1-3 and Comparative Examples 1-5 were subjected to purity testing, and the results are shown in Table 2.

[0126] Table 2 ;

[0127] It can be seen from the above table that the diethyltoluenediamine prepared by the method in Examples 4-6 of the present invention has a higher purity.

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an adsorbent for purifying diethyltoluenediamine, characterized in that: The following steps are involved: S1. Preparation of modified molecular sieve: adding water glass to water, adding pyrrolidine, stirring and mixing to obtain solution 1; adding aluminum sulfate to water, adding concentrated sulfuric acid, stirring and mixing to obtain solution 2; adding solution 2 dropwise to solution 1, heating and stirring to react, adding alkyl orthosilicate and porogen, transferring to a high-pressure stirred reactor with a polytetrafluoroethylene liner, heating and crystallizing, cooling to room temperature, filtering, washing, drying, and calcining to obtain a modified molecular sieve; the porogen is a polyoxyethylene-polyoxypropylene triblock copolymer PEO20-PPO70-PEO20 or PEO106-PPO70-PEO106; S2 dealumination: preparing an acid solution, adding a modified molecular sieve, heating and stirring the reaction, filtering, washing, drying, and calcining to obtain a dealumination modified molecular sieve; the acid solution is a mixed solution of 1-2mol / L hydrochloric acid and 0.5-1mol / L sulfuric acid; S3 metal ion modification: the dealuminated molecular sieve is added to water, a metal ion salt is added, the reaction is heated and stirred, filtered, washed, and dried to obtain a metal ion modified dealuminated molecular sieve; the metal ion salt comprises strontium chloride and barium chloride in a mass ratio of 3-5:10; S4. Polymer modification: mixing a metal ion modified dealuminated molecular sieve, diethyltoluenediamine, a functional monomer, a crosslinking agent, and a porogen, adding an initiator under inert gas protection, heating the polymerization reaction, filtering, and drying to obtain a polymer modified molecular sieve; the functional monomer comprises 4-vinylpyridine and butyl methacrylate in a mass ratio of 7-10:2-4, the crosslinking agent is ethylene glycol dimethacrylate; the porogen is acetone; S5. Preparation of adsorbent: Adding polymer-modified molecular sieves to a Soxhlet extractor, eluting with an eluent until diethyltoluenediamine is undetectable, washing, and drying to obtain an adsorbent for purification of diethyltoluenediamine; the eluent used for elution is a dichloromethane-ethyl acetate mixture in a volume ratio of 10:1-2.

2. The preparation method according to claim 1, characterized in that: The mass ratio of water glass, pyrrolidine, aluminum sulfate, concentrated sulfuric acid, alkyl orthosilicate and porogen in step S1 is 12-15:2-4:7-9:1-3:3-5:0.1-0.2, the temperature of the heating and stirring reaction is 35-45°C, the time is 20-24h, the temperature of the heating crystallization is 130-140°C, the time is 56-72h, and the calcination temperature is 500-600°C, and the time is 4-6h.

3. The preparation method according to claim 1, characterized in that: The temperature of the heating and stirring reaction in step S2 is 75-85°C, and the time is 3-5 hours. The temperature of the calcination is 500-600°C, and the time is 4-6 hours.

4. The preparation method according to claim 1, characterized in that: In step S3, the mass ratio of the dealuminated modified molecular sieve to the metal ion salt is 100:3-6, and the temperature of the heating and stirring reaction is 60-80° C. for 3-5 hours.

5. The preparation method according to claim 1, characterized in that: In step S4, the mass ratio of the metal ion modified dealuminated molecular sieve, diethyltoluenediamine, functional monomer, crosslinking agent, porogen and initiator is 100:5-7:22-25:0.5-0.7:2-3:0.1-0.2, the initiator is selected from at least one of sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutyronitrile, azobisisoheptanenitrile and benzoyl peroxide, the temperature of the heating polymerization reaction is 50-60°C, and the time is 1-3h.

6. An adsorbent for purifying diethyltoluenediamine obtained by the preparation method according to any one of claims 1 to 5.

7. A method for using the adsorbent for purifying diethyltoluenediamine as claimed in claim 6, characterized in that: The adsorbent is loaded into a column, the prepared diethyltoluenediamine product is added, eluted, the eluate is collected, and the solvent is removed under reduced pressure to obtain diethyltoluenediamine.

8. The application method according to claim 7, characterized in that: The eluent used for the elution is a dichloromethane-ethyl acetate mixture with a volume ratio of 10:1-2.