阅读说明：本技术 一种两性离子交换树脂及其制备方法 (Amphoteric ion exchange resin and preparation method thereof ) 是由 高志男 李晨 王娇娇 李永胜 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种两性离子交换树脂及其制备方法,首先,利用聚苯乙烯磺酸树脂与吡啶反应制得磺酸吡啶盐树脂；然后,磺酸吡啶盐树脂与氯化亚砜回流反应制得聚苯乙烯磺酰氯树脂；最后,聚苯乙烯磺酰氯树脂再与三乙烯四胺反应即得两性离子交换树脂。本发明的两性离子交换树脂具有功能基含量高的特点,同时该树脂能够高效的分离回收电镀废水中的重金属离子及其螯合物,且制备过程不会用到致癌的氯甲基化试剂,环保无污染。(The invention discloses an amphoteric ion exchange resin and a preparation method thereof, firstly, polystyrene sulfonic acid resin is reacted with pyridine to prepare pyridinium sulfonate resin; then, carrying out reflux reaction on the pyridinium sulfonate resin and thionyl chloride to prepare polystyrene sulfonyl chloride resin; finally, the polystyrene sulfonyl chloride resin reacts with triethylene tetramine to obtain the amphoteric ion exchange resin. The amphoteric ion exchange resin has the characteristic of high content of functional groups, can efficiently separate and recover heavy metal ions and chelates thereof in electroplating wastewater, does not use carcinogenic chloromethylation reagents in the preparation process, and is environment-friendly and pollution-free.)

1. An amphoteric ion exchange resin characterized by the following basic structure:

2. the amphoteric ion exchange resin of claim 1, wherein the amphoteric ion exchange resin has a sulfonic acid functional group content of 2.55 to 3.32mmol/g, an amino functional group content of 1.19 to 2.67mmol/g, and a total functional group content of 4.51 to 5.22 mmol/g.

3. A process for the preparation of amphoteric ion exchange resins according to claim 1 or 2, comprising the steps of:

(1) weighing 10-20 parts by weight of polystyrene sulfonic acid resin, adding into a reaction container, adding 20-40 parts by weight of absolute ethyl alcohol, swelling for 2-6h, adding 30-50 parts by weight of pyridine, stirring overnight at 20-40 ℃, pouring out reaction liquid after the reaction is finished, filtering, washing with absolute ethyl alcohol and distilled water respectively, filtering, and drying under reduced pressure at 60 ℃ to obtain pyridinium sulfonate resin;

the polystyrene sulfonic acid resin is gel or macroporous resin, and the crosslinking degree of the polystyrene sulfonic acid resin is 4-12%;

(2) weighing 5-10 parts by weight of pyridinium sulfonate resin prepared in the step (1), adding the pyridinium sulfonate resin into a reaction container, adding 10-30 parts by weight of solvent A, swelling for 2-6h, adding 15-40 parts by weight of thionyl chloride, carrying out reflux reaction at 30-50 ℃ for 5-12h, evaporating redundant thionyl chloride after the reaction is finished, slowly pouring the residue and the resin into ice water in batches under stirring to remove the residual thionyl chloride, washing with solvent B and deionized water respectively, filtering, and drying to obtain polystyrene sulfonyl chloride resin;

the solvent A is dichloromethane or dichloroethane;

the solvent B is acetone or diethyl ether;

(3) weighing 3-10 parts by weight of the polystyrene sulfonyl chloride resin prepared in the step (2), adding the polystyrene sulfonyl chloride resin into a four-neck flask, adding 8-20 parts of tetrahydrofuran to swell for 2-6h, adding 15-30 parts of triethylene tetramine, reacting for 7-12h at 30-45 ℃, pouring out after the reaction is finished, respectively washing for 2 times by using concentrated hydrochloric acid and deionized water, filtering, and drying to obtain the amphoteric ion exchange resin.

Technical Field

The invention belongs to the technical field of ion exchange resin, and particularly relates to amphoteric ion exchange resin and a preparation method thereof.

Background

Amphoteric resin refers to ion exchange resin which has both anion and cation exchange groups in the same resin, and the two groups in the resin are close to each other to form inner salt, which can simultaneously perform anion and cation exchange and can be regenerated by water, thus being widely applied to separation and purification of biomacromolecules, desalination of concentrated electrolyte and the like. The commercial product Retardation 11A8 resin from Dowex company in America is used for treating wastewater containing high-concentration NaSCN polyacrylonitrile and desalting concentrated alkali liquor, and has better effect; in 2002, Zhouyanghua and the like report that the PSN amphoteric adsorption resin is prepared by taking aniline and concentrated sulfuric acid as raw materials. In the resin, the negative and positive functional groups are fixed on the same monomer, and the monomer is uniformly distributed in the resin, so that the mixing of the negative and positive functional groups at the molecular level can be macroscopically ensured, and the salt absorption capacity of the amphoteric adsorption resin is remarkably improved.

Electroplating is one of the global heavy pollution industries at present, and according to incomplete statistics, the electroplating wastewater discharged by the electroplating industry of China is about 40 hundred million m each year³The electroplating wastewater has complex water quality and difficult control of components, contains a large amount of heavy metal ions and chelates thereof, and some of the electroplating wastewater belongs to carcinogenic, teratogenic and mutagenic highly toxic substances and has great harm to human beings. The electroplating wastewater is recycled by sewage and precious metals, so that not only can water resources be saved and heavy metals be recycled, but also the pollution of the heavy metals to water can be effectively solved, and the ecological environment is protected. The traditional ion exchange resin and the amphoteric resin thereof are difficult to effectively separate heavy metal ions and chelates thereof in electroplating wastewater.

Disclosure of Invention

The invention aims to solve the problem that the amphoteric resin cannot effectively separate and recover heavy metal ions and chelates thereof in the electroplating industry, and provides an amphoteric ion exchange resin prepared by taking polystyrene sulfonic acid resin, pyridine, thionyl chloride and triethylene tetramine as raw materials, which can effectively and simultaneously separate the heavy metal ions and chelates thereof in electroplating wastewater.

Technical principle of the invention

The invention discloses an amphoteric ion exchange resin and a preparation method thereof, firstly, polystyrene sulfonic acid resin reacts with pyridine to generate pyridinium sulfonate resin; then, the pyridinium sulfonate resin reacts with thionyl chloride to generate polystyrene sulfonyl chloride resin which is used as a reaction intermediate; finally, reacting the polystyrene sulfonyl chloride resin with triethylene tetramine to prepare the amphoteric ion exchange resin, wherein the reaction equation in the preparation process is as follows:

technical scheme of the invention

An amphoteric ion exchange resin, the basic structure of which is as follows:

the content of sulfonic acid functional groups in the amphoteric ion exchange resin is 2.55-3.32mmol/g, the content of amino functional groups is 1.19-2.67mmol/g, and the content of total functional groups is 4.51-5.22 mmol/g.

The preparation method of the amphoteric ion exchange resin comprises the following steps:

(1) weighing 10-20 parts by weight of polystyrene sulfonic acid resin, adding into a reaction container, adding 20-40 parts by weight of absolute ethyl alcohol, swelling for 2-6h, adding 30-50 parts by weight of pyridine, stirring overnight at 20-40 ℃, pouring out reaction liquid after the reaction is finished, filtering, washing with absolute ethyl alcohol and distilled water respectively, filtering, and drying under reduced pressure at 60 ℃ to obtain pyridinium sulfonate resin;

the polystyrene sulfonic acid resin is gel or macroporous resin, and the crosslinking degree of the polystyrene sulfonic acid resin is 4-12%;

(2) weighing 5-10 parts by weight of pyridinium sulfonate resin prepared in the step (1), adding the pyridinium sulfonate resin into a reaction container, adding 10-30 parts by weight of solvent A, swelling for 2-6h, adding 15-40 parts by weight of thionyl chloride, carrying out reflux reaction at 30-50 ℃ for 5-12h, evaporating redundant thionyl chloride after the reaction is finished, slowly pouring the residue and the resin into ice water in batches under stirring to remove the residual thionyl chloride, washing with solvent B and deionized water respectively, filtering, and drying to obtain polystyrene sulfonyl chloride resin;

the solvent A is dichloromethane or dichloroethane;

the solvent B is acetone or diethyl ether;

(3) weighing 3-10 parts by weight of the polystyrene sulfonyl chloride resin prepared in the step (2), adding the polystyrene sulfonyl chloride resin into a four-neck flask, adding 8-20 parts of tetrahydrofuran to swell for 2-6h, adding 15-30 parts of triethylene tetramine, reacting for 7-12h at 30-45 ℃, pouring out after the reaction is finished, respectively washing for 2 times by using concentrated hydrochloric acid and deionized water, filtering, and drying to obtain the amphoteric ion exchange resin.

The invention has the beneficial effects that:

the invention discloses an amphoteric ion exchange resin, which contains triethylene tetramine chain segments, can form coordination with heavy metal chelate in electroplating wastewater, and is firmly adsorbed on the resin, and sulfonic acid groups in the resin can exchange with the heavy metal ions in the electroplating wastewater, so that the resin can effectively separate and recover the heavy metal ions and the heavy metal chelate in the electroplating wastewater at one time, the discharged wastewater reaches the national discharge standard, the pollution of heavy metal to water is reduced, and the heavy metal can be recovered and reused; the resin can effectively and conveniently remove heavy metals and chelates thereof, reduces the production investment of enterprises, avoids the pollution to the environment, and meets the long-term development requirements of the enterprises and the environment.

The invention also discloses a preparation method of the amphoteric ion exchange resin, wherein polystyrene sulfonyl chloride resin is used as a reaction intermediate, the polystyrene sulfonyl chloride resin can be prepared by directly sulfonating and sulfonylating the polystyrene resin, and the traditional highly toxic chloromethylation reagent is avoided in the whole reaction link, so that the harm to production personnel and environment can be reduced.

In conclusion, the method has the characteristics of high efficiency, environmental protection and no pollution, can effectively and conveniently separate and recover the heavy metal and the chelate thereof in the electroplating wastewater, and does not use carcinogenic chloromethylation reagent in the preparation process.

Drawings

FIG. 1 is an infrared spectrum of the amphoteric ion exchange resin obtained in example 1.

Detailed Description

The invention is further illustrated, but not limited, by the following specific examples.

The experimental reagents in the following examples were purchased from Shanghai chemical reagent, Inc., national drug group; polystyrene sulfonic acid resins were purchased from shanghai resin factories.