CN104448133B - A kind of preparation method and application of PAMC - Google Patents

Abstract

The invention discloses a preparation method and application of cationic polyacrylamide. The present invention adopts microwave heating mode, uses nano- _SiO2 dispersion liquid, dimethyl diallyl ammonium chloride and acrylamide monomer as raw materials, vegetable oil as continuous phase, uses redox initiator to initiate reaction, and injects nitrogen to drive After oxygen, react in a microwave reactor for a period of time, then transfer to a water bath, and continue heating in the reaction system. The cationic polyacrylamide latex product is produced by emulsion polymerization, demulsified with acetone, washed and purified with absolute ethanol, dried and pulverized to obtain a powdery cationic polyacrylamide product, which is used to treat Cr ⁶⁺ ions, When Hg ²⁺ ion, phenol and dimethyl phthalate, its removal rate can reach more than 40%. The preparation process of the invention is simple, and the prepared product has good solubility, and can be widely used in multiple industries such as heavy metal waste water treatment, organic waste water treatment, sludge dehydration and the like.

Description

A kind of preparation method and application of cationic polyacrylamide

technical field

The invention belongs to the technical field of preparation of water treatment agents and environmental protection engineering, and in particular relates to a preparation method and application of microwave-assisted initiation of novel cationic polyacrylamide.

Background technique

At present, my country's water environment is generally polluted, among which heavy metals and organic matter are two important types of pollutants. These pollutants are stable in nature, difficult to decompose, and can be enriched in organisms. They have strong carcinogenic, teratogenic, and mutagenic effects. , so it is necessary to synthesize low-energy and high-efficiency water treatment agents for such pollutants.

At present, water treatment agents are mainly divided into inorganic flocculants, organic flocculants, biological flocculants and composite flocculants. However, with the increasingly complex water environment, traditional flocculants can no longer meet the needs well. Therefore, a new type of flocculant that not only has the effect of traditional flocculants but also has exclusive adsorption effects has been synthesized and prepared for the characteristic pollutants in the water environment. Dosage is significant.

Cationic polyacrylamide is an important class of organic water treatment agent. It has the advantages of small dosage, good treatment effect and wide application. However, there are some shortcomings in the traditional synthesis method, such as long synthesis time. Therefore, the synthetic time Short, effective and low-cost water treatment agents for heavy metal ions and organic pollutants in the water environment are urgent problems for water treatment workers.

Contents of the invention

The first purpose of the present invention is to provide a kind of cationic polyacrylamide which has better solubility, can effectively remove heavy metal ions and organic matter in the water environment at the same time, and is easy for industrial production to address the shortcomings of existing polyacrylamide products. Preparation.

The present invention realizes above-mentioned object technical scheme as:

A preparation method of cationic polyacrylamide, comprising the steps of:

(1) At 20-25°C, mix sorbitan oleate, that is, Span-80, with vegetable oil and evenly add it to the container, and its mass concentration is controlled at 0.1-2.0% and 10-50% respectively;

(2) Prepare nano- _SiO2 particle dispersion, then this nano- _SiO2 particle dispersion, dimethyl diallyl ammonium chloride monomer and acrylamide monomer aqueous solution are added in the container successively, control the total amount of monomer The mass concentration is 10-50%, stir to make it evenly mixed, and emulsify at 20-25°C for 20-60 minutes;

(3) Add an oxidation-reduction initiator to the container, the total mass concentration of which is controlled at 0.01 to 0.5%, and continue to emulsify for 20 to 60 minutes;

(4) Add 1 mol/L ethylenediaminetetraacetic acid disodium salt, i.e. EDTA aqueous solution as a complexing agent, and the mass concentration is controlled at 0.02% to 0.5%;

(5) Introduce nitrogen for 10 to 50 minutes to achieve the purpose of removing oxygen in the monomer mixture;

(6) Place the container in a microwave reactor, turn on the microwave, control the microwave power at 20-100W, raise the temperature to 40-120°C, then keep the temperature constant, react for 3-15 minutes to polymerize;

(7) After the reaction is completed, take out the container, and then place it in a water bath at 30-70°C, and continue the reaction for 1-5 hours;

(8) A certain amount of acetone is slowly poured into the container, and the latex product is demulsified;

(9) Wash the demulsified product with absolute ethanol, dry it, and crush it into a powdery solid to obtain the product.

It should be noted that the above mass concentrations are all relative to the total mass of reactants.

Further, the vegetable oil is preferably peanut oil, soybean oil or rapeseed oil.

Further, the preparation method of the nano- _SiO2 particle dispersion is: ultrasonically disperse the nano- _SiO2 for 2.0 hours, and then control the hydrolysis of tetraethyl orthosilicate under alkaline conditions to obtain nano-SiO2 with polymerizable functional groups on the surface. ₂ particle dispersion.

Further, the oxidant in the oxidation-reduction initiator is one or a mixture of two or more of hydrogen peroxide, sodium peroxide, calcium peroxide, dibenzoyl oxide or dilauroyl peroxide; the reducing agent is N,N-dipropyl-1-propanamine, N,N-dimethylaniline, cobalt naphthenate, manganese naphthenate, calcium naphthenate, methyl mercaptan, ethanethiol, coenzyme A and organometallic compounds one or a mixture of two or more.

Further, in the step (2), the molar ratio of the nano-SiO ₂ in the nano-SiO ₂ dispersion, the dimethyldiallylammonium chloride monomer and the acrylamide monomer is 10-80:10-80: 80-10.

The second object of the present invention is to provide the application of the novel cationic polyacrylamide prepared by the above method, that is, after the solid product is made into a solution, it is used to remove heavy metal Cr ⁶⁺ ions, Hg ²⁺ ions, phenol, orthobenzene in the water environment. Dimethyl dicarboxylate.

The cationic degree of the polymerization product prepared by the invention is 10-90%.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

(1) The preparation method of the present invention adopts the polymerization of three kinds of monomers, and takes nano _- SiO as the core, which can make the intrinsic viscosity of the product evenly distributed.

(2) The present invention adopts a microwave-assisted initiation polymerization process, which can make full use of the microwave thermal effect and microwave non-thermal effect, and heat and polymerize the synthesized monomer from the molecular level, which can shorten the time for product preparation, and the product has better solubility.

(3) The cationic polyacrylamide prepared by the present invention has a good removal effect on heavy metal ions and organic matter, and its removal rate reaches more than 40%, which can expand the application range of the cationic polyacrylamide.

detailed description

The present invention will be described in further detail below in conjunction with specific examples, but the present invention is not limited thereto.

Example 1

(1) At 20-25°C, first mix 1.0g Span80 and 30.0g rapeseed oil into the container evenly;

(2) add successively again prepared nano-SiO ₂ dispersion liquid (it contains nano-SiO ₂ quality is 5g), dimethyl diallyl ammonium chloride monomer 15.5g (mass fraction is 60%) and acrylamide 20.0g monomer (dissolve it in 20mL distilled water), stir at high speed to mix and emulsify evenly for 30min;

(3) Add 0.15 g of initiator oxidized hydrogen peroxide and 0.05 g of methyl mercaptan, and emulsify for 30 min;

(4) After emulsification, add 0.8 mL of complexing agent 1.0 mol/L EDTA aqueous solution;

(5) Feed nitrogen for 30 minutes to achieve the purpose of removing oxygen in the monomer mixture;

(6) Place the container in a microwave reactor, turn on the microwave, control the microwave power to 20W, raise the temperature to 60°C, keep the temperature constant, and react for 3 minutes to make it polymerize;

(7) After the reaction in the microwave reactor is completed, the container is taken out, and then placed in a water bath at 60°C, and the reaction is continued for 2 hours;

(8) slowly pour the acetone of 50mL into the latex-like product, and carry out demulsification;

(9) Finally, the demulsified product is washed with 35 mL of absolute ethanol;

(10) measure its intrinsic viscosity with Ubbelohde viscometer to be 5.3dL/g;

(11) Place the cationic polyacrylamide in an oven at 70°C, dry it, and then pulverize it into a powdery solid for use.

Example 2

(1) At 20-25°C, first mix 0.6g Span80 and 20.0g soybean oil into the container;

(2) add successively again prepared nano-SiO ₂ dispersion liquid (it contains nano-SiO ₂ quality is 6g), dimethyl diallyl ammonium chloride monomer 25.5g (mass fraction is 60%) and acrylamide Monomer 8.5g (dissolve it in 12mL distilled water), stir at high speed to make it evenly mixed and emulsified for 30min;

(3) Add 0.1 g of initiator hydrogen peroxide and 0.05 g of ethanethiol, and emulsify for 30 min;

(4) After emulsification, add 0.8 mL of complexing agent 1.0 mol/L EDTA aqueous solution;

(5) Feed nitrogen for 40 minutes to achieve the purpose of removing oxygen in the monomer mixture;

(6) Place the container in a microwave reactor for initiation, turn on the microwave, control the microwave power to 40W, heat up to 60°C, then keep the temperature constant, and react for 2 minutes to polymerize;

(7) After the reaction in the microwave reactor is completed, the container is taken out, and then placed in a water bath at 60°C, and the reaction is continued for 3 hours;

(8) Slowly pour the acetone of 50mL into the white latex product, and carry out the demulsification process;

(9) Finally, the demulsified product is washed with 30 mL of absolute ethanol;

(10) Measure its intrinsic viscosity with Ubbelohde viscometer to be 6.2dL/g;

(11) Place the dimethyl diallyl ammonium chloride acrylamide copolymer in an oven at 75°C and dry it, then pulverize it into a powdery solid for use.

Example 3

The product obtained in Example 2 is applied to the removal of Cr in water, ^{Hg ions} , phenol, dimethyl phthalate:

(1) analyze the concentration of ^Cr ion, Hg ^ion , phenol, dimethyl phthalate in the water to be treated;

( ^{2) Calculate the reaction amount of cationic polyacrylamide according to the concentration of Cr in water, Hg 2+ ion} , phenol, dimethyl phthalate, and the flocculant cationic polyacrylamide contained in water (embodiment) 2 the resulting product) in an amount of 0.01 to 20 mg/L.

(3) The removal process is:

(1) Transport water containing Cr ⁶⁺ ions, Hg ²⁺ ions, phenol, and dimethyl phthalate to the reactor, and add flocculant cations to the reactor through the dosing pipe according to the above reaction ratio polyacrylamide; at the same time, start the agitator to fully stir the above-mentioned water body and the flocculant, (stirring at a speed of 350r/min for 2 minutes, and then stirring at a speed of 60r/min for 6 minutes), through the flocculation of the flocculant Therefore, the concentrations of Cr ⁶⁺ ions, Hg ²⁺ ions, phenol and dimethyl phthalate in the water environment are reduced by more than 40%.

(2) The water body treated in the step (1) is left to stand for 1-10 hours; the flocculant cationic polyacrylamide and its adsorbate in the water are settled to the bottom through flocculation and sedimentation.

Table 1 is the experimental data table of applying the product obtained in Example 2 of the present invention to remove Cr in water, ^{Hg ions} , phenol, dimethyl phthalate:

Table 1

Cr ⁶⁺ ions in the water environment, Hg ²⁺ ions, phenol, and dimethyl phthalate are adsorbed by the flocculant cationic polyacrylamide through flocculation to settle and thereby removed. The cationic polyacrylamide prepared by the present invention is flocculated The agent can make the adsorption rate of Cr ⁶⁺ ions, Hg ²⁺ ions, phenol and dimethyl phthalate more than 40%.

Claims (5)

1. a preparation method of cationic polyacrylamide is characterized in that comprising the steps: (1) At 20-25°C, mix sorbitan oleate, that is, Span-80, with vegetable oil and evenly add it to the container, and its mass concentration is controlled at 0.1-2.0% and 10-50% respectively; (2) Prepare nano- _SiO2 particle dispersion, then this nano- _SiO2 particle dispersion, dimethyl diallyl ammonium chloride monomer and acrylamide monomer aqueous solution are added in the container successively, control the total amount of monomer The mass concentration is 10-50%, stir to make it evenly mixed, and emulsify at 20-25°C for 20-60 minutes; (3) Add an oxidation-reduction initiator to the container, the total mass concentration of which is controlled at 0.01 to 0.5%, and continue to emulsify for 20 to 60 minutes; (4) Add 1 mol/L ethylenediaminetetraacetic acid disodium salt, i.e. EDTA aqueous solution as a complexing agent, and the mass concentration is controlled at 0.02% to 0.5%; (5) Introduce nitrogen for 10-50 minutes; (6) Put the container in a microwave reactor, turn on the microwave, control the microwave power at 20-100W, raise the temperature to 40-120°C, then keep the temperature constant, and react for 3-15min; (7) After the reaction is completed, the container is taken out, and then placed in a water bath at 30-70°C, and the reaction is continued for 1-5 hours; (8) A certain amount of acetone is poured into the container, and the latex product is demulsified; (9) washing the product after demulsification with absolute ethanol, drying and pulverizing into a powdery solid to obtain the product; Wherein, the oxidant in the oxidation-reduction initiator is one or a mixture of two or more of hydrogen peroxide, sodium peroxide, calcium peroxide, dibenzoyl peroxide or dilauroyl peroxide; reducing agent It is one of N,N-dipropyl-1-propanamine, N,N-dimethylaniline, cobalt naphthenate, manganese naphthenate, calcium naphthenate, methyl mercaptan, ethanethiol, coenzyme A a mixture of two or more. 2. The preparation method of cationic polyacrylamide according to claim 1, characterized in that: the vegetable oil is peanut oil, soybean oil or rapeseed oil. 3. the preparation method of cationic polyacrylamide according to claim 1 is characterized in that the preparation method of described nano- _SiO2 particle dispersion is: with nano- _SiO2 Ultrasonic dispersion 2.0 hours, then under alkaline condition control normal Tetraethyl silicate is hydrolyzed to obtain a dispersion of nano- _SiO2 particles with polymerizable functional groups on the surface. 4. the preparation method of cationic polyacrylamide according to claim 1 is characterized in that: in described step ( _{2), nano-SiO in dispersion liquid 2 ,} dimethyl diallyl ammonium chloride The molar ratio of the monomer to the acrylamide monomer is 10-80:10-80:80-10. 5. the application of the cationic polyacrylamide prepared by the method according to any one of claims 1 to 4 in removal of Cr ⁶⁺ ions, Hg ²⁺ ions, phenol, dimethyl phthalate in water environment.