A resin for adsorbing o-nitroaniline and a method for preparing the same

Abstract

The application discloses a resin for adsorbing o-nitroaniline and a preparation method thereof, and belongs to the technical field of resin production. After polystyrene resin is subjected to a chloroacetylation reaction, the polystyrene resin is reacted with octadecylamine to graft long-chain alkyl, imino and carbon groups on the molecular chain structure of the polystyrene resin. The long-chain alkyl can form a network winding structure, facilitating the contact adsorption of the resin and o-nitroaniline and enhancing the hydrophobicity of the resin. Hydrophobic interaction and hydrogen bond interaction exist between the grafted polystyrene resin and o-nitroaniline, which can improve the adsorption performance of the resin on o-nitroaniline in wastewater, is beneficial to the recovery of o-nitroaniline in the wastewater and reduces the pollution caused by wastewater discharge.

Description

TECHNICAL FIELD

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

[0002] O-phenylenediamine is mainly used for producing benzimidazole fungicides such as carbendazim and thiophanate-methyl. O-phenylenediamine is prepared by reducing o-nitroaniline, and the toxicity of o-nitroaniline is greater than that of aniline. O-nitroaniline can enter the human body through skin contact and is a strong hematin formation agent. The formed hematin can cause hypoxia of human tissues and damage to the central nervous system, cardiovascular system and other organs. At present, the production of o-nitroaniline mainly adopts the ammonolysis method. A large amount of wastewater containing o-nitroaniline is generated in the production process. As a main product in the workshop, o-nitroaniline is not fully recovered, which not only causes resource waste but also causes great pressure on the subsequent wastewater treatment process and causes damage to the environment. Therefore, it is of great significance to recover o-nitroaniline in wastewater.

[0003] Macroporous adsorption resin is a high molecular polymer that has the function of concentrating and separating organic matters. According to the surface properties of the resin, the adsorption resin is generally divided into three types of nonpolar adsorption resin, moderately polar resin and polar resin. The nonpolar adsorption resin is an adsorption resin without any functional groups and is prepared from monomers with small dipole moments. A typical example is the adsorption resin of a styrene-divinylbenzene system, which is widely used in the adsorption and recovery of o-nitroaniline.

[0004] Due to the weak research on the structure-activity relationship between macroporous adsorption resin and target molecules and the separation rules, it is difficult to realize the directional design and preparation of the resin, so that the selectivity and specificity of the resin are not strong, and the adsorption and separation effect is not high. Therefore, improving the adsorption performance of the resin is a hot and important point. SUMMARY

[0005] The purpose of the present application 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 wastewater.

[0006] The purpose of the present application can be realized by the following technical solutions.

[0007] The present application provides a resin for adsorbing o-nitroaniline, which comprises a polymer with the following molecular structure:

[0008]

[0009] Wherein, n=1000-5000.

[0010] The present application further provides a preparation method of the resin for adsorbing o-nitroaniline, comprising the following steps:

[0011] (1) the polystyrene resin is dispersed in an organic solvent, chloroacetyl chloride is added dropwise, and aluminum chloride is added under nitrogen, and the reaction is stirred at room temperature for 2h;

[0012] (2) the resin is filtered out after the reaction, washed, and dried at 50℃ for 4h;

[0013] (3) the dried resin is placed in a swelling agent and swelled for 2h;

[0014] (4) aluminum chloride and octadecylamine are added to the swelled resin, heated to 60℃, and stirred for 12h;

[0015] (5) the solution after the reaction is filtered to obtain the resin, washed, and dried at 50℃ for 4h to obtain the finished resin.

[0016] Further, the organic solvent is dichloromethane, and the addition amount of the polystyrene resin is 0.01g / mL.

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

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

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

[0020] The resin is washed with tetrahydrofuran, 5wt% hydrochloric acid solution, and deionized water, respectively, each for 1 time, and then washed with anhydrous ethanol for 3 times.

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

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

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

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

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

[0026] The resin is washed with anhydrous ethanol, 1mol / L sodium hydroxide aqueous solution, and deionized water, respectively, each for 1 time, and then washed with anhydrous ethanol until neutral.

[0027] The beneficial effects of the present application are:

[0028] By grafting long-chain alkyl, imino and carbonyl on the molecular chain of polystyrene resin, on the one hand, the long-chain alkyl is used to increase the hydrophobicity of the polystyrene resin, and the long-chain alkyl can form a network winding structure, so that when the polystyrene resin adsorbs o-nitroaniline in waste water, the two are in full contact due to hydrophobic interaction, thereby increasing the adsorption efficiency; on the other hand, due to the hydrogen bond effect between the carbonyl and the amino group, the adsorption force 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 technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] Embodiment 1

[0031] The present embodiment provides a resin for adsorbing o-nitroaniline, the resin comprising a polymer having the following molecular structure:

[0032]

[0033] wherein n = 1000-5000.

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

[0035] (1) A closed container is added with dichloromethane, polystyrene resin (XDA-1 type macroporous adsorption resin) is weighed according to a concentration of 0.01 g / mL and added into the container, after stirring and dispersing, chloroacetyl chloride is slowly added dropwise, then nitrogen is filled into the closed container, aluminum chloride is added, and stirring is performed at room temperature for 2 h, 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, filtration is performed, the resin is taken out, and the resin is sequentially washed once with tetrahydrofuran, 5 wt% hydrochloric acid solution and deionized water, and then washed three times with anhydrous ethanol. After washing, the resin is dried at a constant temperature of 50°C for 4 h;

[0037] (3) The dried resin is added into a container, and tetrahydrofuran is added, and the two are mixed and swelled for 2 h, wherein the concentration of the resin in tetrahydrofuran is 0.1 g / mL;

[0038] (4) After the resin swelling is completed, aluminum chloride and octadecylamine are added to the container, and the mixture is heated to 60°C and stirred for 12h, wherein the molar ratio of octadecylamine to resin is 1:1, and the molar ratio of aluminum chloride to octadecylamine is 1:0.6;

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

[0040] Example 2

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

[0042] Example 3

[0043] The difference from Example 1 is that the molar ratio of aluminum chloride to chloroacetyl chloride in step (1) is 0.6:1, and the other steps and conditions are the same as those 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 those 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 those in Example 2.

[0048] Example 6

[0049] The difference from Example 4 is that the molar ratio of aluminum chloride to octadecylamine in step (4) 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 the molar ratio of aluminum chloride to octadecylamine in step (4) 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 of this comparative example is XDA-1 type macroporous adsorption resin.

[0054] Adsorption of o-nitroaniline in wastewater by the resins of Example 1-7 and Comparative Example 1: The wastewater with o-nitroaniline concentration of 500 mg / L was adjusted to pH 8, 0.1 g of the resins in Examples and Comparative Example was respectively taken, and then was swelled in water and placed in a conical flask, 100 mL of the wastewater was taken and placed in the conical flask, and then was shaken at 30℃ for 12 h, and the adsorption rate of o-nitroaniline in the wastewater was measured, and the results are shown in Table 1:

[0055] Table 1

[0056]

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

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

[0059] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations of these embodiments can be made without departing from the principles and spirits of the present application, and the scope of the present application 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 according to 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, stirring and reacting at room temperature for 2 h; (2) After the reaction, the resin was filtered out, washed, and dried at 50°C for 4 h; (3) Place the dried resin in a swelling agent and allow it to swell for 2 hours; (4) adding aluminum chloride and octadecylamine to the swollen resin, heating to 60°C and stirring for 12 hours; (5) The reaction solution was filtered to remove the resin, which was washed and dried at 50°C for 4 hours to obtain the finished resin.

3. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, wherein: 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, wherein: 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, wherein: 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, wherein: 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 three times.

7. The method for preparing a resin for adsorbing o-nitroaniline according to claim 2, wherein: 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, wherein: 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, wherein: The molar ratio of octadecylamine to 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.

Images