Resin for adsorbing o-nitroaniline and preparation method thereof

Abstract

The invention discloses a resin for adsorbing o-nitroaniline and a preparation method thereof, and belongs to the technical field of resin production, polystyrene resin is subjected to a chloroacetylation reaction and then reacts with octadecylamine, a long-chain alkyl group, an imino group and a carbon group are grafted on a molecular chain structure of the polystyrene resin, the long-chain alkyl group can form a network winding structure, and the long-chain alkyl group can form a network winding structure; the contact adsorption of the resin and o-nitroaniline is facilitated, and the hydrophobicity of the resin can be enhanced. Hydrophobic interaction and hydrogen-bond interaction exist between the grafted polystyrene resin and the o-nitroaniline, the adsorption performance of the resin to the o-nitroaniline in the wastewater can be improved, recovery of the o-nitroaniline in the wastewater is facilitated, and wastewater discharge pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of resin production, and particularly relates to a resin for adsorbing o-nitroaniline and a preparation method thereof. Background Art

[0002] O-phenylenediamine is mainly used in the production of benzimidazole fungicides, such as carbendazim and methyl thiophanate. O-phenylenediamine is prepared by reducing o-nitroaniline. O-nitroaniline is more toxic than aniline and can enter the human body through skin contact. It is a strong methemoglobin former. The formed methemoglobin can cause hypoxia in human tissues and damage the central nervous system, cardiovascular system and other organs. At present, the production of o-nitroaniline mainly adopts the ammonolysis method, and a large amount of wastewater is generated in its production process. The wastewater contains o-nitroaniline. As the main product of the workshop, o-nitroaniline, if not fully recovered, will not only cause waste of resources, but also cause great pressure on the subsequent wastewater treatment process and cause certain damage to the environment. Therefore, it is of great significance to recover o-nitroaniline in the wastewater.

[0003] Macroporous adsorption resin is a high molecular polymer that has the effect of concentrating and separating organic matter. According to the surface properties of the resin, adsorption resin is generally divided into three categories: non-polar adsorption resin, neutral polar resin and polar resin. Non-polar adsorption resin is an adsorption resin without any functional group made from monomer polymers with very small dipole moment. A typical example is the adsorption resin of styrene-divinylbenzene system, which is widely used in the adsorption recovery of o-nitroaniline.

[0004] Since the research on the structure-activity relationship between macroporous adsorption resins and target molecules and their separation rules is relatively weak, it is difficult to achieve directional design and preparation of resins, resulting in low selectivity and specificity of the resins and low adsorption and separation effects. Therefore, improving the adsorption performance of resins has become a hot topic and focus of people's attention. Summary of the invention

[0005] The purpose of the present invention is to provide a resin for adsorbing o-nitroaniline and a preparation method thereof, so as to improve the adsorption performance of the resin on o-nitroaniline in waste water.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The present invention provides a resin for adsorbing o-nitroaniline, wherein the resin comprises a polymer having the following molecular structure:

[0008]

[0009] Among them, n=1000-5000.

[0010] The present invention also provides a method for preparing a resin for adsorbing o-nitroaniline, comprising the following steps:

[0011] (1) Dispersing polystyrene resin in an organic solvent, adding chloroacetyl chloride dropwise, and then adding aluminum chloride under nitrogen, and stirring the reaction at room temperature for 2 hours;

[0012] (2) After the reaction, filter out the resin, wash it, and dry it at 50°C for 4 hours;

[0013] (3) placing the dried resin in a swelling agent and allowing it to swell fully for 2 hours;

[0014] (4) adding aluminum chloride and octadecylamine to the swollen resin, heating to 60° C. and stirring for 12 h;

[0015] (5) The reaction solution was filtered to remove the resin, which was washed and dried at 50° C. for 4 h to obtain the finished resin.

[0016] Furthermore, the organic solvent is dichloromethane, and the dosage of the polystyrene resin is 0.01 g / mL.

[0017] Furthermore, the molar ratio of the chloroacetyl chloride to the polystyrene resin is 1:1.

[0018] Furthermore, the molar ratio of aluminum chloride to chloroacetyl chloride in (1) is 0.5-0.6:1.

[0019] Furthermore, the washing step in (2) is as follows:

[0020] The resin was washed with tetrahydrofuran, 5 wt % hydrochloric acid solution and deionized water in sequence, once each, and then washed with anhydrous ethanol for three times.

[0021] Further, the swelling agent is one of tetrahydrofuran, NN-dimethylformamide and toluene;

[0022] Furthermore, the concentration of the resin in the swelling agent in (3) is 0.1 g / mL.

[0023] Furthermore, the molar ratio of aluminum chloride to octadecylamine in (4) is 1:0.6-0.7.

[0024] Furthermore, the molar ratio of octadecylamine to resin in (4) is 1.0-1.5:1.

[0025] Furthermore, the washing step in (5) is as follows:

[0026] The resin was washed with anhydrous ethanol, 1 mol / L sodium hydroxide aqueous solution and deionized water in sequence, once each, and then washed with anhydrous ethanol until neutral.

[0027] Beneficial effects of the present invention:

[0028] By grafting long-chain alkyl, imino and carbonyl groups on the molecular chain of polystyrene resin, on the one hand, the long-chain alkyl groups are used to increase the hydrophobicity of the polystyrene resin, and the long-chain alkyl groups can form a network entanglement structure, so that when the polystyrene resin adsorbs o-nitroaniline in wastewater, the two are fully in contact due to hydrophobic interaction, thereby increasing the adsorption efficiency; on the other hand, due to the hydrogen bonding effect between the carbonyl group and the amino group, the adsorption capacity of the polystyrene resin on o-nitroaniline is enhanced, and the grafted polystyrene resin has excellent adsorption performance on o-nitroaniline. DETAILED DESCRIPTION

[0029] 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.

[0030] Example 1

[0031] This embodiment provides a resin for adsorbing o-nitroaniline, and the resin includes a polymer with the following molecular structure:

[0032]

[0033] Among them, n=1000-5000.

[0034] The preparation steps of the above resin are as follows:

[0035] (1) Add dichloromethane to a sealed container, weigh a polystyrene resin (XDA-1 macroporous adsorption resin) at a concentration of 0.01 g / mL and add it to the container, stir and disperse, then slowly drop chloroacetyl chloride, then fill the sealed container with nitrogen, add aluminum chloride, and stir and react at room temperature for 2 hours, wherein the molar ratio of chloroacetyl chloride to polystyrene resin is 1:1, and the molar ratio of aluminum chloride to chloroacetyl chloride is 0.5:1;

[0036] (2) After the reaction is completed, filter and take out the resin, wash the resin with tetrahydrofuran, 5wt% hydrochloric acid solution and deionized water once each, and then wash it with anhydrous ethanol three times. After washing, dry the resin at a constant temperature of 50°C for 4 hours;

[0037] (3) Add the dried resin into a container, then add tetrahydrofuran, mix the two and fully swell for 2 hours, wherein the concentration of the resin in tetrahydrofuran is 0.1 g / mL;

[0038] (4) After the resin has swollen, add aluminum chloride and octadecylamine to the container, heat to 60° C., and stir to react for 12 hours, wherein the molar ratio of octadecylamine to the resin is 1:1, and the molar ratio of aluminum chloride to octadecylamine is 1:0.6;

[0039] (5) The solution after the reaction in the container is filtered, and the resin is taken out. The resin is washed with anhydrous ethanol, 1 mol / L sodium hydroxide aqueous solution and deionized water, respectively, and then washed with anhydrous ethanol until neutral. The washed resin is dried at 50° C. for 4 hours to obtain a finished resin.

[0040] Example 2

[0041] The difference from Example 1 is that in step (1), the molar ratio of aluminum chloride to chloroacetyl chloride is 0.55:1, and the other steps and conditions are the same as in Example 1.

[0042] Example 3

[0043] The difference from Example 1 is that in step (1), the molar ratio of aluminum chloride to chloroacetyl chloride is 0.6:1, and the other steps and conditions are the same as in Example 1.

[0044] Example 4

[0045] The difference from Example 2 is that the molar ratio of octadecylamine to resin in step (4) is 1.3:1, and the other steps and conditions are the same as in Example 2.

[0046] Example 5

[0047] The difference from Example 2 is that the molar ratio of octadecylamine to resin in step (4) is 1.5:1, and the other steps and conditions are the same as in Example 2.

[0048] Example 6

[0049] The difference from Example 4 is that in step (4), the molar ratio of aluminum chloride to octadecylamine is 1:0.65, and the other steps and conditions are the same as those in Example 4.

[0050] Example 7

[0051] The difference from Example 4 is that in step (4), the molar ratio of aluminum chloride to octadecylamine is 1:0.7, and the other steps and conditions are the same as those in Example 4.

[0052] Comparative Example 1

[0053] The resin used in this comparative example is XDA-1 type macroporous adsorption resin.

[0054] The resins of Examples 1 to 7 and Comparative Example 1 were used to adsorb o-nitroaniline in wastewater: the pH of wastewater with an o-nitroaniline concentration of 500 mg / L was adjusted to 8, 0.1 g of the resins of the Examples and Comparative Examples were respectively taken, swollen with water and placed in a conical flask, 100 mL of wastewater was taken and placed in a conical flask, and vibrated at 30° C. for 12 h, and the adsorption rate of o-nitroaniline in the wastewater was measured. The results are shown in Table 1:

[0055] Table 1

[0056]

[0057] As can be seen from Table 1, under the same adsorption time, the adsorption rate of o-nitroaniline in wastewater by the resin prepared in Examples 1-7 is significantly improved compared with Comparative Example 1. In Examples 1-3, the proportion of the catalyst aluminum chloride in step (1) is appropriately increased to promote the chloroacetylation of polystyrene resin, increase the grafting rate, and improve the adsorption efficiency of the resin. Based on Example 2, Examples 4 and 5 increase the molar ratio of octadecylamine to the resin to promote grafting modification, and the adsorption rate reaches the optimal 99%. Examples 6 and 7 gradually reduce the catalyst content of the octadecylamine grafting reaction in step (4), resulting in a decrease in the grafting rate and a decrease in the adsorption performance of the resin.

[0058] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A resin for adsorbing o-nitroaniline, characterized in that: The resin includes a polymer with the following molecular structure: Among them, n=1000-5000.

2. A method for preparing a resin for adsorbing o-nitroaniline as claimed in claim 1, characterized in that: The following steps are involved: (1) Dispersing polystyrene resin in an organic solvent, adding chloroacetyl chloride dropwise, and then adding aluminum chloride under nitrogen, and stirring the reaction at room temperature for 2 hours; (2) After the reaction, filter out the resin, wash it, and dry it at 50°C for 4 hours; (3) placing the dried resin in a swelling agent and allowing it to swell fully for 2 hours; (4) adding aluminum chloride and octadecylamine to the swollen resin, heating to 60° C. and stirring for 12 h; (5) The reaction solution was filtered to remove the resin, which was washed and dried at 50° C. for 4 h to obtain the finished resin.

3. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The organic solvent is dichloromethane, and the dosage of the polystyrene resin is 0.01 g / mL.

4. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The molar ratio of the chloroacetyl chloride to the polystyrene resin is 1:

1.

5. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The molar ratio of aluminum chloride to chloroacetyl chloride in (1) is 0.5-0.6:

1.

6. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The washing steps in (2) are as follows: The resin was washed with tetrahydrofuran, 5 wt % hydrochloric acid solution and deionized water in sequence, once each, and then washed with anhydrous ethanol for three times.

7. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The swelling agent is one of tetrahydrofuran, NN-dimethylformamide and toluene; the concentration of the resin in the swelling agent in (3) is 0.1 g / mL.

8. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The molar ratio of aluminum trichloride to octadecylamine in (4) is 1:0.6-0.

7.

9. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The molar ratio of octadecylamine to the resin in (4) is 1.0-1.5:

1.

10. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, characterized in that: The steps of washing in (5) are as follows: The resin was washed with anhydrous ethanol, 1 mol / L sodium hydroxide aqueous solution and deionized water in sequence, once each, and then washed with anhydrous ethanol until neutral.

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