Method for catalytically synthesizing 1, 4-butanediol diacrylate

Abstract

The invention discloses a method for catalytically synthesizing 1, 4-butanediol diacrylate. The preparation method comprises the following steps: firstly, polymerizing paraformaldehyde and p-toluenesulfonic acid under the catalytic action of concentrated sulfuric acid to form a solid paraformaldehyde sulfonic acid catalyst; then, acrylic acid, 1, 3-butadiene, a paraformaldehyde sulfonic acid catalyst and a polymerization inhibitor are added into a reactor, a stirring reaction is performed at the reaction temperature of 30-60 DEG C, acrylic acid and 1, 3-butadiene are catalyzed to be subjected to an acid addition esterification reaction, 1, 4-butanediol diacrylate is synthesized, and the product yield is higher than 98%. The preparation process of the solid paraformaldehyde sulfonic acid catalyst is simple, the reaction of catalyzing the esterification reaction of acrylic acid and 1, 3-butadiene is carried out in a solvent-free system, the reaction conditions are mild and easy to control, the product yield is high, the product and the catalyst are easy to separate, and industrial conversion application is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemical industry, and in particular to a preparation method and application of a solid acid catalyst for catalyzing the addition esterification of 1,3-butadiene and acrylic acid to synthesize 1,4-butanediol diacrylate. Background Art

[0002] 1,4-Butanediol diacrylate is an important bifunctional acrylate monomer, which can be used in the synthesis of high-performance adhesives, coatings, ion exchange resins, rubbers, crosslinkers of synthetic resins, radiation-cured coatings and inks, photosensitive resin printing plates, etc. At present, 1,4-butanediol diacrylate is usually synthesized by direct acid-catalyzed dehydration esterification of acrylic acid and 1,4-butanediol in liquid acids (such as sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, etc.); however, the homogeneous acid-catalyzed synthesis process is usually accompanied by the production of by-product water, and cyclohexane needs to be used as a water-carrying agent; and the use of liquid acid catalysts not only has a great corrosion effect on the reaction equipment, but also requires more water to wash the crude product in the product refining stage, ultimately generating a large amount of acidic chemical wastewater, which requires complicated waste acid post-treatment (Applied Chemical Industry, 2015, 44(03): 394-396+400). Therefore, the synthesis of 1,4-butanediol diacrylate using solid acid heterogeneous catalysts has attracted widespread attention due to its advantages such as low corrosion to equipment and low environmental pollution. 2- / TiO2-SnO2 is a solid acid catalyst, and the acid-catalyzed synthesis process of 1,4-butanediol diacrylate has been studied in depth (Fine Chemicals, 2018, 35(02): 333-339), but the catalytic efficiency and product yield still need to be improved. In view of the bottleneck faced by the catalytic synthesis of 1,4-butanediol diacrylate in the above method, it is of great significance to develop a new and efficient solid acid catalyst and a green catalytic synthesis method of 1,4-butanediol diacrylate. Summary of the invention

[0003] The present invention provides a method for synthesizing 1,4-butanediol diacrylate by catalytic addition esterification in a solvent-free system using 1,3-butadiene and acrylic acid as raw materials under the catalytic action of a solid heterogeneous acid catalyst (as shown in the following formula). The method includes providing a preparation method of a high-performance solid polyformaldehyde sulfonic acid catalyst.

[0004]

[0005] In order to solve the technical problem of the present invention, the following technical solution is adopted:

[0006] A method for catalytically synthesizing 1,4-butanediol diacrylate comprises adding a certain amount of 1,3-butadiene and acrylic acid, a polymerization inhibitor and a certain amount of solid polyformaldehyde sulfonic acid catalyst into a reactor, setting the reaction temperature, reacting under stirring, and analyzing the reaction conversion rate and product yield by a gas chromatograph.

[0007] The reaction is carried out in the absence of a solvent.

[0008] The reaction temperature is 30-60°C.

[0009] The catalyst dosage is 0.02-0.1 g, acrylic acid is 0.06 mol, and 1,3-butadiene is 0.03 mol.

[0010] In the reaction system, one or two of tert-butyl alcohol, hydroquinone, bisphenol A and tetrachlorobenzoquinone are used as polymerization inhibitors.

[0011] The molar ratio of acrylic acid to 1,3-butadiene is 1:0.5.

[0012] The solid polyformaldehyde sulfonic acid catalyst can be recovered and reused in the catalytic addition esterification reaction of 1,3-butadiene and acrylic acid, and the catalytic activity remains stable after being reused 10 times.

[0013] The method for synthesizing 1,4-butanediol diacrylate by acid addition esterification does not use a liquid acid catalyst, and the product and the solid acid catalyst are easy to separate.

[0014] The specific preparation method of the solid polyformaldehyde sulfonic acid catalyst is as follows: 20g of p-toluenesulfonic acid and 5g of polyformaldehyde are placed in a 50mL flask; then, 0.2g of sulfuric acid with a mass concentration of 98% is added, and stirred at 80-120°C for 24h to form a black solid, wherein the function of the sulfuric acid is to promote polymerization; then, the product is collected by filtration and washed with deionized water until SO4 2- All are removed; finally, dried at 100°C overnight to obtain a solid polyformaldehyde sulfonic acid catalyst.

[0015] Advantages of the present invention:

[0016] 1. The solid polyformaldehyde sulfonic acid catalyst prepared by the present invention is prepared by mixing polyformaldehyde and p-toluenesulfonic acid under the action of concentrated sulfuric acid to form a porous polymer, and then washing, filtering and drying to obtain the catalyst. The preparation method is simple to operate, and the prepared solid polyformaldehyde sulfonic acid catalyst has excellent catalytic performance;

[0017] 2. Solid polyformaldehyde sulfonic acid catalyst is strongly acidic;

[0018] 3. Solid polyformaldehyde sulfonic acid catalyst catalyzes the addition esterification reaction of 1,3-butadiene and acrylic acid, with high conversion rate and the selectivity of the product 1,4-butanediol diacrylate greater than 99%;

[0019] 4. The reaction of 1,3-butadiene and acrylic acid provided by the present invention is carried out in a solvent-free system, the product and the catalyst are easy to separate, the operation is simple, economical and environmentally friendly, and has good application prospects.

[0020] Description of the attached figure

[0021] Figure 1 (a) Infrared spectrum of solid polyformaldehyde sulfonic acid catalyst; (b) XRD powder diffraction pattern of polyformaldehyde sulfonic acid catalyst;

[0022] Figure 2 NH3-TPD diagram of solid polyformaldehyde sulfonic acid catalyst;

[0023] Figure 3 Schematic diagram of the recycling effect of solid polyformaldehyde sulfonic acid catalyst. DETAILED DESCRIPTION

[0024] Example 1

[0025] A method for catalytically synthesizing 1,4-butanediol diacrylate, the specific method is as follows: 20g of p-toluenesulfonic acid and 5g of polyformaldehyde are placed in a 50mL flask; then, 0.2g of sulfuric acid with a mass concentration of 98% is added, and stirred at 80-120°C for 24h to form a black solid, wherein the function of the sulfuric acid is to promote polymerization; then, the product is collected by filtration and washed with deionized water until SO4 2- Finally, it was dried at 100°C overnight to obtain a solid polyformaldehyde sulfonic acid catalyst. Figure 1 (a) It shows that the polyformaldehyde sulfonic acid catalyst has abundant sulfonic acid groups; Figure 1 (b) shows that the polyformaldehyde sulfonic acid catalyst is an amorphous powder; Figure 2 This indicates that the polyformaldehyde sulfonic acid catalyst has obvious acidity.

[0026] Example 2-11

[0027] A method for catalytically synthesizing 1,4-butanediol diacrylate, the specific method is as follows: using the solid polyformaldehyde sulfonic acid catalyst in Example 1 to catalyze the esterification reaction of acrylic acid and 1,3-butadiene, the specific method is as follows: 0.06 mol of acrylic acid, 0.03 mol of 1,3-butadiene, 0.1 g of solid polyformaldehyde sulfonic acid catalyst, 0.1 g of tert-butyl alcohol and 0.1 g of hydroquinone are added to a reactor, heated to a certain temperature, reacted for a specified time under stirring, and the reaction was monitored by a gas chromatograph. The specific reaction results are shown in Table 1.

[0028] Table 1. The reaction results of acrylic acid and 1,3-butadiene catalyzed by solid polyformaldehyde sulfonic acid catalyst at different temperatures and times

[0029]

[0030] Examples 12-16

[0031] A method for catalytically synthesizing 1,4-butanediol diacrylate, the specific method is as follows: 0.06 mol acrylic acid, 0.03 mol 1,3-butadiene, a specified amount of solid polyformaldehyde sulfonic acid catalyst, 0.1 g tert-butanol and 0.1 g hydroquinone are added into a reactor, and heated to 45° C., reacted for 3 hours under stirring, and the reaction was monitored by gas chromatography. The specific reaction results are shown in Table 2.

[0032] Table 2. The reaction results of acrylic acid and 1,3-butadiene catalyzed by solid polyformaldehyde sulfonic acid catalyst at different catalyst dosages

[0033]

[0034] Examples 17-25

[0035] A method for catalytically synthesizing 1,4-butanediol diacrylate, the specific method is as follows: 0.06 mol of acrylic acid, 0.03 mol of 1,3-butadiene, 0.1 g of a solid polyformaldehyde sulfonic acid catalyst, and 0.1 g of each of one or two of a specified polymerization inhibitor are added into a reactor, and heated to 45° C., reacted for 3 hours under stirring, and the reaction was monitored by gas chromatography. The specific reaction results are shown in Table 3.

[0036] Table 3. The reaction results of acrylic acid and 1,3-butadiene catalyzed by solid polyformaldehyde sulfonic acid catalyst in the presence of different inhibitors

[0037]

[0038] Embodiment 26

[0039] A method for catalytically synthesizing 1,4-butanediol diacrylate, the specific method is as follows: the solid polyformaldehyde sulfonic acid catalyst in Example 11 is separated and recovered by filtration, and then added into a reactor containing 0.06 mol acrylic acid, 0.03 mol 1,3-butadiene, 0.1 g tert-butyl alcohol and 0.1 g hydroquinone, and heated to 45° C., and reacted for 3 hours under stirring. Figure 3 The solid polyformaldehyde sulfonic acid was used 10 times, and the acrylic acid conversion rate was higher than 96%, and the selectivity of 1,4-butanediol diacrylate was higher than 99%.

Claims

1. A method for catalytic synthesis of 1,4-butanediol diacrylate, characterized in that: Firstly, polyformaldehyde and p-toluenesulfonic acid are polymerized under the catalytic action of sulfuric acid to form a solid polyformaldehyde sulfonic acid catalyst; then, the solid polyformaldehyde sulfonic acid catalyst is used to catalyze the acid addition esterification reaction of acrylic acid and 1,3-butadiene to synthesize 1,4-butanediol diacrylate.

2. A method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: Place 20g p-toluenesulfonic acid and 5g paraformaldehyde in a 50mL three-necked flask; then add 0.2g of 98% concentrated sulfuric acid and stir at 80-120℃ for 24h to form a black solid; then filter and wash with deionized water until SO4 2- All are removed; finally, dried at 100°C overnight to obtain a solid polyformaldehyde sulfonic acid catalyst.

3. A method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: The prepared solid polyformaldehyde sulfonic acid catalyst contains abundant sulfonic acid group strong acid catalytic sites.

4. A method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: The prepared solid polyformaldehyde sulfonic acid catalyst catalyzes the addition esterification of acrylic acid and 1,3-butadiene to synthesize 1,4-butanediol diacrylate under solvent-free conditions at a reaction temperature of 30-60°C.

5. The method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: The catalyst dosage is 0.02-0.1 g, acrylic acid is 0.06 mol, and 1,3-butadiene is 0.03 mol.

6. The method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: In the reaction system, one or two of tert-butyl alcohol, hydroquinone, bisphenol A and tetrachlorobenzoquinone are used as polymerization inhibitors.

7. The method for catalytic synthesis of 1,4-butanediol diacrylate according to claim 1, characterized in that: The solid polyformaldehyde sulfonic acid catalyst can be recovered and reused in the catalytic addition esterification reaction of 1,3-butadiene and acrylic acid. The catalytic activity remains stable after being reused 10 times.

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