Preparation method of polymerization degree-controllable cellulose-based heavy metal ion absorbent

Abstract

The invention discloses a preparation method of a polymerization degree-controllable cellulose-based heavy metal ion absorbent. The method comprises the following steps: sufficiently dissolving cellulose in a mixed solution of anhydrous lithium chloride and polar solvent by utilizing a microwave method, then enabling the cellulose to react with an amide polymer by virtue of an ARGET ATRP method, thus obtaining the cellulose-based heavy metal ion absorbent. The preparation method is short in time consumption and simple in process, and capable of overcoming the weaknesses of a nonhomogenous grafting copolymerization method for preparing the cellulose absorptive heavy metal material that the actual consumption is large, the production process is long, the reaction is difficult to control, andthe product is non-uniform. By adopting the method disclosed by the invention, the heavy metal residue problem can be maximally solved, the requirement on the catalyst is extremely low, and the method is an ideal way of the ATRP extension method with the least residual amount of the catalyst. The basic raw material of the invention is from agricultural and forestry waste, so that the preparationmethod has the advantages of low cost, biodegradability, and renewability, and is a method for utilizing the biomass resource in a high-valuation manner.

Description

technical field

[0001] The invention relates to the technical field of heavy metal ion pollution control, in particular to a preparation method of a cellulose-based heavy metal ion adsorbent with a controllable degree of polymerization. technical background

[0002] With the rapid development of modern industry, the heavy metal content in the environment continues to increase due to mining, sewage irrigation, exhaust gas discharge, use of heavy metal products, and human activities that violate the laws of nature's metabolism for a long time, exceeding the normal range and seriously deteriorating the environmental quality. In recent years, shocking heavy metal pollution incidents have occurred one after another. For example, in January 2012, the cadmium pollution incident in Longjiang, Guangxi, seriously threatened the drinking water safety of residents along the coast and downstream. The downstream Liuzhou City Citizens panicked to buy water, which brought great difficulties...

Examples

Embodiment 1

[0030] 1. Pass the bagasse cellulose through a 80-mesh sieve, take 1g (0.0062mol) of bagasse cellulose, add 50ml of N,N-dimethylacetamide, and then add 5g (0.1180mol) of anhydrous lithium chloride. After processing in a microwave digestion apparatus at a temperature of 130°C for 20 minutes, stir at room temperature for 3 hours to obtain a fully dissolved transparent solution;

[0031] 2. Transfer the solution in step 1 to an ice bath (10°C), stir and add 3.5g of 2-bromoisobutyryl bromide, and then continue stirring for 60 minutes. When the reaction temperature reaches 70°C, fill with nitrogen and add 1.50ml of three Ethylamine, keep the pH neutral, and react at a constant temperature of 70°C for 10 hours;

[0032] 3. Pour the reaction solution of step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 35°C, and then alternately wash with deionized water and methan...

Embodiment 2

[0037] 1. Pass the bagasse cellulose through a 60-mesh sieve, take 1g (0.0062mol) bagasse cellulose, add 40ml N, N-dimethylformamide, then add 4g (0.1180mol) anhydrous lithium chloride, at 400W power, 80 After processing in a microwave digestion apparatus at a temperature of ℃ for 30 minutes, stir at room temperature for 3 hours to obtain a fully dissolved transparent solution;

[0038] 2. Transfer the solution in step 1 to an ice bath (6°C), stir and add 2.5g of 2-bromoisobutyryl bromide, then continue to stir for 40min, when the reaction temperature reaches 50°C, fill with nitrogen and add 1ml of triethyl Amines, keep the pH neutral, and react at a constant temperature of 50°C for 8 hours;

[0039] 3. Pour the reaction solution in step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 25°C, and then alternately wash with deionized water and methanol for 5 times...

Embodiment 3

[0044] 1. Pass bagasse cellulose through a 80-mesh sieve, take 1g (0.0062mol) bagasse cellulose, add 45ml N, N-hexamethylphosphoric triamide, then add 4.5g (0.1180mol) anhydrous lithium chloride, in 600W Power and temperature of 100°C in a microwave digestion apparatus for 10 minutes, then stirred at room temperature for 2 hours to obtain a fully dissolved transparent solution;

[0045] 2. Transfer the solution in step 1 to an ice bath (4°C), stir and add 3g of 2-bromoisobutyryl bromide, and then continue stirring for 50 minutes. When the reaction temperature reaches 65°C, fill with nitrogen and add 1.23ml of triethyl Amines, keep the pH at neutral, and react at a constant temperature of 60°C for 9 hours;

[0046] 3. Pour the reaction solution in step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 30°C, and then alternately wash it with deionized water and met...

technical field

[0001] The invention relates to the technical field of heavy metal ion pollution control, in particular to a preparation method of a cellulose-based heavy metal ion adsorbent with a controllable degree of polymerization. technical background

[0002] With the rapid development of modern industry, the heavy metal content in the environment continues to increase due to mining, sewage irrigation, exhaust gas discharge, use of heavy metal products, and human activities that violate the laws of nature's metabolism for a long time, exceeding the normal range and seriously deteriorating the environmental quality. In recent years, shocking heavy metal pollution incidents have occurred one after another. For example, in January 2012, the cadmium pollution incident in Longjiang, Guangxi, seriously threatened the drinking water safety of residents along the coast and downstream. The downstream Liuzhou City Citizens panicked to buy water, which brought great difficulties...

Examples

Embodiment 1

[0030] 1. Pass the bagasse cellulose through a 80-mesh sieve, take 1g (0.0062mol) of bagasse cellulose, add 50ml of N,N-dimethylacetamide, and then add 5g (0.1180mol) of anhydrous lithium chloride. After processing in a microwave digestion apparatus at a temperature of 130°C for 20 minutes, stir at room temperature for 3 hours to obtain a fully dissolved transparent solution;

[0031] 2. Transfer the solution in step 1 to an ice bath (10°C), stir and add 3.5g of 2-bromoisobutyryl bromide, and then continue stirring for 60 minutes. When the reaction temperature reaches 70°C, fill with nitrogen and add 1.50ml of three Ethylamine, keep the pH neutral, and react at a constant temperature of 70°C for 10 hours;

[0032] 3. Pour the reaction solution of step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 35°C, and then alternately wash with deionized water and methan...

Embodiment 2

[0037] 1. Pass the bagasse cellulose through a 60-mesh sieve, take 1g (0.0062mol) bagasse cellulose, add 40ml N, N-dimethylformamide, then add 4g (0.1180mol) anhydrous lithium chloride, at 400W power, 80 After processing in a microwave digestion apparatus at a temperature of ℃ for 30 minutes, stir at room temperature for 3 hours to obtain a fully dissolved transparent solution;

[0038] 2. Transfer the solution in step 1 to an ice bath (6°C), stir and add 2.5g of 2-bromoisobutyryl bromide, then continue to stir for 40min, when the reaction temperature reaches 50°C, fill with nitrogen and add 1ml of triethyl Amines, keep the pH neutral, and react at a constant temperature of 50°C for 8 hours;

[0039] 3. Pour the reaction solution in step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 25°C, and then alternately wash with deionized water and methanol for 5 times...

Embodiment 3

[0044] 1. Pass bagasse cellulose through a 80-mesh sieve, take 1g (0.0062mol) bagasse cellulose, add 45ml N, N-hexamethylphosphoric triamide, then add 4.5g (0.1180mol) anhydrous lithium chloride, in 600W Power and temperature of 100°C in a microwave digestion apparatus for 10 minutes, then stirred at room temperature for 2 hours to obtain a fully dissolved transparent solution;

[0045] 2. Transfer the solution in step 1 to an ice bath (4°C), stir and add 3g of 2-bromoisobutyryl bromide, and then continue stirring for 50 minutes. When the reaction temperature reaches 65°C, fill with nitrogen and add 1.23ml of triethyl Amines, keep the pH at neutral, and react at a constant temperature of 60°C for 9 hours;

[0046] 3. Pour the reaction solution in step 2 into a mixed solution of methanol and deionized water with a volume ratio of 1:1 to wash the precipitate. The temperature of the precipitation reaction solution is 30°C, and then alternately wash it with deionized water and met...