CN1869088A - Water soluble organic amphoteric high molecule copolymer and its preparation method - Google Patents

Abstract

The invention relates to a water-soluble organic amphoteric polymer copolymer and a preparation method thereof. The water-soluble amphoteric organic polymer copolymer uses itaconic acid (salt) and quaternized alkyl diallyl as comonomers, and is added as a polymerization aid Under the condition of existence, it is obtained by using a redox initiator and a water-soluble azo initiator to initiate a monomer through aqueous solution copolymerization. The preparation method adopted in the invention is simple, the degree of anion and cation is controllable, the molecular weight of the product is high, the content of residual monomer is low, and the water solubility is good. The water-soluble organic amphoteric polymer copolymer prepared by the invention can be used as a flocculant for waste water treatment.

Description

Water-soluble organic amphoteric polymer copolymer and preparation method thereof

Technical field The present invention relates to a water-soluble organic amphoteric polymer copolymer and a preparation method.

Background technology Water is an indispensable material material in human life and production activities. According to the 2004 China Environmental Quality Report, more than 90% of the rivers and lakes in China have been polluted to varying degrees. Some pollution even endangers the safety of survival. Preventing water pollution has become a basic national policy of our country. Flocculants are widely used in wastewater treatment. The proportion of flocculant used in domestic and foreign hydrometallurgy, petrochemical, papermaking, steel, textile, printing and dyeing, food, brewing and other industries accounts for 55-75%, while almost 100% of the tap water industry uses flocculation as a purification method .

Flocculants can be divided into inorganic and organic flocculants according to their chemical composition. Inorganic flocculants are gradually being replaced by organic flocculants because of their large dosage, large impact on water quality, and secondary pollution. Organic flocculants are divided into two categories: natural and synthetic. Due to current technical reasons, the quality of natural organic flocculants is not stable, which limits their practical application. Organic synthetic polymer flocculants have been paid more and more attention because they can control the molecular structure, are less affected by water quality, have relatively low dosage, and have good flocculation effects. Organic synthetic polymer flocculants are divided into: non-ionic, such as polyacrylamide, "Water Treatment Chemicals Handbook" [M], the first edition in May 2005, Chemical Industry Press, edited by He Tielin, introduced acrylamide Polymerized nonionic flocculant, but its residual monomers and decomposed small molecules are toxic, and its application is limited; anionic, such as polyacrylic acid (salt), "Petrochemical Industry" [J], 2005, 34 (4 ): 338~342, Yang Xianping and others synthesized acrylamide-sodium acrylate copolymer anionic flocculant, which is also restricted due to secondary pollution caused by monomer residue and decomposition toxicity; cationic, such as quaternary ammonium salt polymerization or The product obtained by the copolymerization of quaternary ammonium salt and acrylamide, and the Mannich reaction of polyacrylamide. Chinese patent CN1202144A discloses a cationic flocculant. Due to the greatly increased organic matter content in modern industrial and domestic wastewater, the surface of organic particles is negatively charged. Therefore, cationic flocculants have better flocculation, but in sludge treatment, due to the continuation of sludge corruption, using cationic flocculants alone will result in low recovery of suspended solids and high moisture content of dehydrated cakes. Zwitterions have the characteristics of anions and cations, and have stronger flocculation and sedimentation effects than cationic flocculants. The performance of sludge dewatering is more obvious and effective, and the dosage is less. It can also act as a metal chelating agent. Due to many Fine particles and colloids containing positive and negative charges in sewage need to be treated with zwitterionic flocculants, so they have more advantages in water treatment. "Practical Handbook of Water Treatment Agents and Materials" [M], the first edition in March 2000, Published by Sinopec Press, edited by Qi Luliang, Li Yongcun, etc., introduced an amphoteric polymer ion flocculant formed by copolymerization of sodium acrylate, acrylamide and quaternary ammonium salt. A cationic macromolecular flocculant and anionic macromolecular flocculant shared method, Chinese patent CN1196334A discloses the preparation method of cationic/amphoteric grafted polyacrylamide flocculant, Chinese patent CN1451612A discloses the preparation method of polyacrylamide flocculant by diethyl diallyl chloride The polymer formed by ammonium, acrylamide and acrylic acid is compounded with polydiethyl diallyl ammonium chloride to form a method for preparing zwitterionic polymer flocculants. A zwitterionic polymer formed by the ternary polymerization of methacryloyloxyethyltrimethylammonium chloride, Li Wanjie and others proposed the use of Manny The method of preparing amphoteric polyacrylamide flocculant by Mannich reaction, Ran Qianping and others reported the use of dimethyl diallyl chloride in Oilfield Chemistry [J], 2002, 19 (1): 85-88 Ammonium, maleic acid and acrylamide are copolymerized into a zwitterionic polymer flocculant.

The polymer flocculants synthesized above still have some different defects:

1. Toxic monomers such as acrylamide, acrylic acid (salt) and maleic acid (salt) are used in the synthesis of polymer flocculants, so the polymerization residual monomers and decomposed small molecules will cause secondary pollution;

2. The polymer flocculant of Mannich modified polyacrylamide is not suitable for treating wastewater with high pH, and its storage stability is not high.

3. From the perspective of green chemistry, the Mannich reaction does not meet the requirements of green chemistry.

The purpose of the present invention is to keep the flocculation efficiency of the water-soluble organic amphoteric macromolecular copolymer without reducing to achieve better performance:

1. The selected monomers are non-toxic, basically do not cause secondary pollution, and are more in line with the requirements of green chemistry;

2. In the copolymerization, redox initiators are selected, and a small amount of azo initiators and polymerization aids are used to achieve the purpose of increasing the conversion rate and reducing residual monomers;

3. It overcomes the shortcomings of poor dehydration effect and unstable performance of polyacrylamide flocculants.

The present invention adopts new technology, and the water-soluble organic amphoteric macromolecular copolymer prepared by the aqueous solution copolymerization of itaconic acid (salt) and quaternized alkyl diallyl provides a kind of simple operation, stable performance and wide application range. An amphoteric polymer flocculant with wider range and better dehydration effect and a preparation method thereof.

This water-soluble organic amphoteric macromolecular copolymer is characterized in that it is itaconic acid (salt) by monomer:

X: H, Na or K

The monomer is a quaternized alkyl diallyl:

R: C ₁ ~C ₄ alkyl; Y: Cl, Br

In the presence of polymerization aids, redox initiators and water-soluble azo initiators are used to initiate the binary copolymers formed by copolymerization of monomers in aqueous solution. The structure of the prepared water-soluble organic amphoteric polymer copolymers is shown in the figure below:

1≤n≤7684; 1≤m≤6190 (n, m are positive integers)

The preparation method of the present invention has no special requirements on the above-mentioned polymerization monomers, redox initiators, water-soluble azo initiators, polymerization aids and the like. For example, for the copolymerization monomer, in the itaconic acid (salt) compound whose general formula can be expressed as CH ₂ ═CCOOX (CH ₂ COOX), X can be H, Na, K; the general formula is (CH ₂ ═CH In the quaternized alkyldiallyl compound of -CH ₂ ) ₂ NRY, R may be an alkyl group containing 1 to 4 carbon atoms, and Y may be Cl or Br. Experimental results show that in order to make the performance and economy of the prepared water-soluble organic amphoteric high molecular copolymer of the present invention reach the best effect, its total monomer concentration is controlled at 5% to 45%, and the molar dosage of the two monomers It is advisable to control the ratio within the range of 1:10 to 1:25.

As mentioned above, the present invention adds a redox initiator at a low temperature in the early stage of polymerization, and its purpose is to obtain a copolymer with a large molecular weight. For example, the selected oxidizing agent can be any one of hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate, and the reducing agent can be sodium bisulfite, sodium sulfite, sodium thiosulfate, sodium hydrosulfate, sodium pyrosulfate , Potassium bisulfite, Potassium sulfite, Ammonium sulfite, Ferric sulfite. Experimental results show that the molar ratio of the redox initiator is 1-1.5, and the ideal effect can be achieved in the range of 0.05%-5% of the total mass of the monomer.

As mentioned above, the present invention adds a water-soluble azo initiator at a higher temperature in the later stage of polymerization, for example, azobisisobutylamidine hydrochloride, dimethyl azobisisobutyrate, azobis(2 -any one of methylpropionamide) hydrochloride, azobis(4-cyanovaleric acid). Experimental results show that the conversion rate of the monomer can reach more than 90% when the amount is within the range of 0.05%-1.0% of the total mass of the monomer.

As mentioned above, the present invention adds polymerization aids in the polymerization reaction, such as diethanolamine, triethanolamine, ethylenediaminetetraacetic acid and its salts, water-soluble fluorine-containing compounds such as fluorosilicic acid, calcium fluorosilicate, potassium fluoride, fluorine Any one or a mixture of two or more of sodium chloride. Experimental results show that its dosage is in the range of 0.025% to 1.0% of the total mass of the monomers, which can make the copolymerization reaction initiated by the redox initiator obtain a water-soluble organic amphoteric polymer copolymer with a large molecular weight, and make its polymerization rate increase. control.

As described in the preparation method of the water-soluble organic amphoteric polymer copolymer, the pH of the polymerization system is adjusted to 2.0 to 8.0, and the substance used to adjust the pH is any of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, and sodium bicarbonate. A kind of aqueous solution, which ensures that the initiator used can achieve the most ideal initiation efficiency.

The preparation method of the present invention is realized through the following steps:

Put the quaternized alkyldiallyl group and distilled water into the reactor at room temperature; start stirring, add itaconic acid (salt) to adjust the pH to 2.0-8.0; vacuumize three times, each time is 10min, and pass through Nitrogen twice, each time 5min; in the case of continuous nitrogen flow, add polymerization aids, redox initiators, raise the temperature to 30°C-50°C, control the copolymerization reaction time at 2-8h; add water-soluble azo Initiator, heat up to 70°C-100°C, continue to react for 2-6h; cool to room temperature to obtain water-soluble organic amphoteric polymer.

The present invention mixes and copolymerizes two kinds of monomers, adds a certain amount of polymerization aids, uses a redox initiator in the early stage, and adds a water-soluble azo initiator in the later stage to ensure that the flocculant has a sufficiently high molecular weight and improves the Conversion, reduced monomer content.

Compared with the existing water-soluble organic polymer amphoteric copolymers used for water treatment, the present invention has the following advantages:

1. The selected monomers are non-toxic;

2. The water-soluble oxidation-reduction system is used as the low-temperature initiator, and the water-soluble azo is used as the accelerator in the later stage, which ensures that the flocculant has a sufficiently high molecular weight, improves the conversion rate, and reduces the monomer content;

3. The preparation method is simple and suitable for popularization and application;

4. Stable performance, suitable for a wide range of pH value, many types of wastewater treatment, small input (only 1-100mg/L), with obvious economic and benefit;

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a chemical reaction formula for the copolymerization of two monomers itaconic acid (salt) and quaternized alkyl diallyl under the action of an initiator and a polymerization assistant to form a binary copolymer.

In conjunction with examples of implementation, the present invention is further described as follows:

Example 1

At room temperature, in a 250mL four-necked bottle equipped with a thermometer, a stirrer, and a nitrogen inlet and outlet, add 19g of dimethyl diallyl ammonium chloride and 80g of distilled water, start stirring, add 1g of itaconic acid, and use 10% hydrogen Adjust the pH of the sodium oxide aqueous solution to 4.5, evacuate 3 times, each time for 10 minutes, pass nitrogen twice in the middle, each time for 5 minutes, continue to pass nitrogen, add 0.025% of the total mass of monomer sodium fluoride and sodium edetate Mixture 0.005g, then add 0.05% of the total mass of monomers of potassium persulfate and sodium bisulfite 0.01g, heat up to 30 ° C, copolymerization reaction for 4 hours; add 0.05% of the total mass of monomers azobisisobutyl Add 0.01 g of amidine hydrochloride, heat up to 70° C., continue to react for 3 hours, then cool and discharge. The monomer conversion rate was 94%, and the molecular weight of the copolymer was 8×10 ⁵ .

Example 2

At room temperature, in a 250mL four-necked bottle equipped with a thermometer, a stirrer, and a nitrogen inlet and outlet, add 34g of dimethyl diallyl ammonium chloride and 60g of distilled water, start stirring, add 6g of itaconic acid, and use 10% hydrogen Adjust the pH of the sodium oxide aqueous solution to 5.5, evacuate 3 times, each time for 10 minutes, pass nitrogen twice in the middle, each time 5 minutes, continue to pass nitrogen, add 0.01 g of sodium ethylenediamine tetraacetate of 0.25% of the total mass of the monomer, and Then add 0.05% of the total mass of the monomers of potassium persulfate and 0.02 g of sodium bisulfite, raise the temperature to 40°C, and perform a copolymerization reaction for 4 hours; add 0.05% of the total mass of the monomers of azobisisobutylamidine hydrochloride 0.02g, the temperature was raised to 70°C, the reaction was continued for 3 hours, and the material was cooled and discharged. The monomer conversion rate was 93.2%, and the molecular weight of the copolymer was 1.5×10 ⁵ .

Example 3

At room temperature, in a 250mL four-necked bottle equipped with a thermometer, a stirrer, and a nitrogen inlet and outlet, add 6g of dimethyl diallyl ammonium chloride and 93.8g of distilled water, start stirring, add 0.2g of itaconic acid, and use 10 % sodium hydroxide aqueous solution to adjust the pH to 7.5, evacuate 3 times, each time for 10 minutes, pass nitrogen gas twice in the middle, each time 5 minutes; Add 0.05% of the total mass of the monomers of potassium persulfate and 0.006 g of sodium bisulfite, raise the temperature to 50°C, and perform a copolymerization reaction for 4 hours; add 0.1% of the total mass of the monomers of azobisisobutylamidine hydrochloride 0.006g of salt, the temperature was raised to 90°C, the reaction was continued for 3 hours, and the mixture was cooled and discharged. The monomer conversion rate was 95%, and the molecular weight of the copolymer was 1×10 ⁴ .

Application example

The NO1, 2, and 3 water-soluble organic amphoteric polymer copolymers prepared in the above examples 1, 2, and 3 were used for flocculation treatment of drilling wastewater, tannery wastewater, and landfill leachate.

Table 1. Wastewater water quality indicators water quality index Drilling wastewater Tannery wastewater landfill leachate pHCOD _Cr (mg/L) Turbidity (NTU) 10.24420683.4 7.83500467.2 9.11386282.7

Table 2. Results of flocculant treatment of wastewater flocculant Drilling wastewater Tannery wastewater landfill leachate Turbidity COD _Cr Turbidity COD _Cr Turbidity COD _Cr Removal rate (%) NO.1NO.2NO.3 87.285.084.8 74.172.371.7 76.974.274.0 64.563.761.8 81.779.177.2 70.668.166.9

Note: The dosage of flocculant is 10mg/L, and the pH of the wastewater can be adjusted to 3-9 before treatment.

Claims (9)

1. A water-soluble organic amphoteric polymer copolymer, which is characterized in that itaconic acid (salt) and quaternized alkyl diallyl are copolymerized from two monomers, and the molecular weight is 1×10 ⁴ to 1×10 ⁶ , the chemical formula is In the formula, X is H, Na or K, R is C ₁ ~C ₄ alkyl, Y is Cl, Br 1≤n≤7684; 1≤m≤6190 (n, m are positive integers) 2, as claimed in claim 1, the preparation method of water-soluble organic amphoteric polymer copolymer is characterized in that itaconic acid (salt) and quaternized alkyl diallyl are copolymerized monomers, in the presence of polymerization aids Under certain conditions, it is prepared by copolymerizing monomers with redox initiators and water-soluble azo initiators through aqueous solution. 3. The water-soluble organic amphoteric polymer copolymer and its preparation method according to any one of claims 1 and 2, characterized in that the comonomer is any one of itaconic acid, sodium itaconate or potassium itaconate and R is a copolymerized monomer composed of any one of chloroquaternized or brominated quaternized alkyl diallyl of C ₁ to C ₄ alkyl, and the total concentration of the polymerized monomer in the aqueous solution is 5% to 45% % (mass percentage), the molar ratio of the two monomers is 1:10 to 1:25. 4. The preparation method of water-soluble organic amphoteric high molecular copolymer as claimed in claim 2 is characterized in that it can be used as redox initiator and refers to that the oxidizing agent is any one of hydrogen peroxide, ammonium persulfate, sodium persulfate and potassium persulfate. One and the reducing agent is a redox consisting of any one of sodium bisulfite, sodium sulfite, sodium thiosulfate, sodium dithionite, sodium pyrosulfite, potassium bisulfite, potassium sulfite, ammonium sulfite, and ferric sulfite Initiator. The molar ratio of the oxidizing agent to the reducing agent substance is 1.0-2.5, and the dosage is 0.05%-5% of the mass of the monomer. 5. The method for preparing water-soluble organic amphoteric polymer copolymers as claimed in claim 2, characterized in that the water-soluble azo initiators are azobisisobutylamidine hydrochloride, azobisisobutyric acid dimethyl Any one of ester, azobis(2-methylpropionamide) hydrochloride and azobis(4-cyanovaleric acid) is used in an amount of 0.05% to 1.0% of the monomer mass. 6. The method for preparing water-soluble organic amphoteric high molecular copolymers as claimed in claim 2, characterized in that diethanolamine, triethanolamine, ethylenediaminetetraacetic acid and its salts, and water-soluble fluorine-containing compounds can be used as polymerization aids. Such as fluosilicic acid, calcium fluosilicate, potassium fluoride, sodium fluoride, or a mixture of two or more, the dosage is 0.025% to 1.0% of the monomer mass. 7. The preparation method of water-soluble organic amphoteric high molecular copolymer as claimed in claim 2 is characterized in that quaternized alkyl diallyl and distilled water are loaded into the reactor at room temperature; stirring is started, and itaconic acid is added acid (salt), adjust the pH to 2.0-8.0; evacuate three times, each time is 10 minutes, and pass nitrogen twice in the middle, each time is 5 minutes; in the case of continuous nitrogen flow, add polymerization aids and redox initiators , raise the temperature to 30°C-50°C, and control the copolymerization reaction time at 2-8h; add a water-soluble azo initiator, raise the temperature to 70°C-100°C, and continue the reaction for 2-6h; cool to room temperature to obtain a water-soluble organic amphoteric high molecular polymer. 8. The preparation method of water-soluble organic amphoteric high molecular copolymer as claimed in claim 2, characterized in that the pH of the aqueous solution of the polymerization reaction is adjusted as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate aqueous solution of any kind. 9. The application of itaconic acid (salt) and quaternized alkyl diallyl water-soluble organic amphoteric polymer copolymer, which is characterized in that it can be used as waste water treatment.