CN110256627B - Free radical polymerization for regulating acrylamide by using cationic monomer as polymerizable halogen source - Google Patents

Abstract

The invention belongs to the field of preparation ofThe field of molecular weight polymers, relates to aqueous solution free radical polymerization of acrylamide. The reaction process of the invention is to use Fe^IIIPolycarboxylic acids or Cu^IIThe polybasic tertiary amine complex ion catalyzes sodium persulfate and water-soluble aliphatic tertiary amine to form an oxidation-reduction initiation system, and acrylamide free radical polymerization is initiated in an aqueous solution containing a small amount of cationic monomer. The invention has the advantages that: the operation is simple, the used raw materials are cheap and are stable to air moisture. Polymerizable organic quaternary ammonium salts (i.e., common cationic monomers) are used as halogen sources instead of free inorganic halides. The cationic monomer contains polymerizable double bonds and halogen ions, and the monomer becomes a part of a polymer chain after polymerization, so that almost no free halogen ions exist, and the cationic monomer can be used in certain occasions with higher requirements on participating inorganic salts, such as chromatographic seasonings and the like. Stable polymerization, no sudden polymerization or crosslinking, high molecular weight and good solubility of the obtained product.

Description

Free radical polymerization for regulating acrylamide by using cationic monomer as polymerizable halogen source

Technical Field

The invention belongs to the field of preparing high molecular weight polymers, relates to free radical polymerization of acrylamide (AAm), and particularly relates to a method for catalyzing free radical polymerization of AAm by using an iron or copper salt complex in an aqueous solution containing a small amount of peroxide, polymerizable tertiary amine and cationic monomers, so that the high molecular weight polymers are formed at a higher polymerization speed by adjusting the polymerization speed, and crosslinked insoluble substances are prevented from being formed by virtue of depolymerization.

Background

Acrylamide (AAm) is one of common water-soluble monomers, and acrylamide homo/copolymer (PAAm) polymerized by taking the acrylamide as a main monomer is used as a general assistant, is called as industrial monosodium glutamate and is widely applied to industries such as papermaking, mineral separation, oil extraction, water treatment and the like. Compared with inverse emulsion polymerization, precipitation polymerization and the like, the aqueous solution free radical polymerization is still the most common production mode for producing various PAAm, although the defects of difficult heat transfer, high energy consumption in a separation link and the like exist. From the viewpoint of improving the production efficiency, the concentration of AAm in the reaction solution should be increased as much as possible to increase the single pot productivity of the reaction vessel, but the heat of reaction due to the polymerization of AAm is large (about 17.4kcal mol.)^-1K.Kishore K.N.Santhanalakshmi Thermal polymerization of acrylamide by differential scanning of Polymer Science of Polymer Chemistry Edition,1981,19,2367-^-1In the ordinary free radical polymerization process, if the polymerization speed is not controlled, the reaction liquid can be heated to over 90 ℃ from room temperature (20-25 ℃) only by polymerization heat release, and great hidden danger is generated for the smooth progress of polymerization. When the reaction temperature is too high, the resultant PAAm tends to easily form a crosslinked structure. On the other hand, if the reduction of AAm in the aqueous solution polymerization systemThe monomer concentration of (2) can greatly reduce the production efficiency and economic benefit. Apparently, in AAm concentration more than 3.75mol L^-1The aqueous radical polymerization system of (1) requires control of the radical active site to reduce the polymerization rate and to lengthen the polymerization reaction time, thereby slowly releasing the heat of polymerization over a longer period of time.

In earlier patent applications, it was proposed that persulfate-polymerizable tertiary amines (e.g., 2- (N, N-dimethylamino) ethyl methacrylate, identified as DMAEMA) are catalyzed by common, inexpensive and stable transition metal salts in a high oxidation state (e.g., copper or iron salt complexes) to form redox systems to initiate polymerization of AAm in aqueous solutions containing free halogen ions (e.g., bromide ions) (CHEN, SUNLANGLE, MIANYONG, Dianthus to prepare superpolymeric acrylamide copolymers by free radical polymerization, published under No. CN 108641035A). In the invention, the persulfate-DMAEMA is used for constituting a redox initiation system, because the DMAEMA contains polymerizable double bonds, part of polymer chains generated by initiation can be further polymerized; on the other hand, free bromide ions added in the form of NaBr in the solution and the copper or iron salt complex form a complex containing halogen ligands in situ, and the propagating radicals are passivated to form carbon-bromine covalent bonds and reduced to be cuprous or ferrous salt complexes. After the persulfate is completely consumed, the cuprous or ferrous salt complex catalyzes a polymer chain with a carbon-bromine covalent bond at the tail end to continuously initiate the polymerization of the residual monomers by an atom transfer radical polymerization mechanism. Since the copper or iron salt complex containing the halogen ligand can continuously passivate the growing free radicals, the instantaneous concentration of the free radicals is low, thereby reducing the polymerization speed. Finally, not only can the polymerization reaction exotherm be controlled, but macroscopic gel formation due to extensive crosslinking is also avoided. However, in this system, most of the NaBr added remains in the polymerization system, and since the viscosity of the system after polymerization is very high, removal is impossible. Such products are therefore not suitable for applications sensitive to salts.

In the present invention, polymerizable organic quaternary ammonium salts (i.e., common cationic monomers) are used as halogen sources instead of free inorganic halides. The cationic monomer contains polymerizable double bonds and halogen ions, and the monomer becomes a part of a polymer chain after polymerization, so that almost no free halogen ions exist, and the cationic monomer can be used in certain occasions with higher requirements on participating inorganic salts, such as chromatographic seasonings and the like.

Disclosure of Invention

The reaction process of the invention is to use Fe^IIIDisodium Ethylenediaminetetraacetate (EDTA) or Cu^IITertiary polyamines (including N, N, N' -Pentamethyldivinyltriamine (PMDETA), tris (2-N, N-dimethylamino) ethylamine (Me)₆TREN) complex ion catalyzes sodium persulfate (NaPS) and water-soluble aliphatic tertiary amine to form an oxidation-reduction initiation system, and free radical polymerization of AAm is initiated in the presence of a small amount of cationic monomers (including methacryloyloxyethyl trimethyl ammonium chloride (DMC), and dimethyl diallyl ammonium chloride (DADMAC). The invention has the advantages that: the method has the advantages of simple operation, low external requirement, cheap and easily-purchased raw materials, stable moisture in air and common cationic monomer as a halogen source. The polymerization is stable, no sudden polymerization or crosslinking exists, and the solubility of the obtained product is good. Free halogen ions in the polymerization system.

The technical scheme adopted by the invention comprises the following specific operation steps:

(1) preparing a reaction solution

According to different reaction conditions, a certain amount of reagents (catalyst mother liquor, water-soluble aliphatic tertiary amine, cationic monomer aqueous solution mother liquor, AAm aqueous solution mother liquor and NaPS aqueous solution mother liquor) of each component are weighed and added into a plastic self-sealing bag in batches, deionized water is added to adjust the total volume to be 100mL, and the components are stirred to be uniformly mixed.

(2) Reaction takes place

And introducing argon into the prepared reaction liquid to remove oxygen for a certain time, and sealing the reaction liquid and then starting the reaction in a water bath at a certain temperature.

(3) Polymer separation

After the polymerization is finished, dissolving the obtained polymer by using water, precipitating and separating out the polymer by using ethanol, and placing the separated molecular weight sample in an oven for drying.

(4) Testing

The viscosity-average molecular weight of the polymer is measured by a viscosity method. What is needed isThe molecular weight of the obtained copolymer sample is measured by a single-point viscosity method, and the method comprises the following specific steps: weighing 0.50-0.70g L^-1The dried polymer was dissolved in deionized water to prepare 100mL of an aqueous polymer solution, and the flow-out times of the deionized water and the polymer solution were measured at 30 ℃ in a water bath using an Ubbelohde viscometer, respectively.

(5) Computing

The intrinsic viscosity ([ eta ]) of the polymer was calculated according to the following formula:

the polymer viscosity average molecular weight was then calculated from the Mark-Houwink equation as follows:

[η]＝kM_ν ^α (2)

wherein k is 0.00631mL g^-1，α＝0.8(M.Kurata,X Tsunashima,Viscosity-molecular weight relationships and unperturbed dimensions of linear chain molecules,in Polymer Handbook,4^th Edition；Eds.:J.Brandrup,E.H.Immergut,E.A.Grulke；Wiley,Pergamon,2003；VII/10)。

Detailed Description

The present invention is further described in detail below with reference to specific examples, which are intended to illustrate the invention and not to limit or narrow the scope thereof.

Example 1:

a total volume of 100mL of aqueous solution was prepared, wherein the initial concentration of AAm (noted as [ AAm ]]₀) Is 4.4mol L^-1DMAEMA starting concentration (noted as [ DMAEMA ]]₀) Is 32mmol L^-1Initial concentration of NaPS (noted as [ NaPS ]]₀) 0.71mmol L^-1DMC onset concentration (noted as [ DMC ]]₀) 12.80mmol L^-1、FeCl₂EDTA initial concentration (noted as [ Fe ]^II/EDTA]₀Wherein [ Fe ]^II]₀:[EDTA]₀Is fixed at an equivalent ratio of 1:1) of 10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, and extrudingRemoving residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.03 × 10⁷。

Example 2:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.4mol L^-1、[DMAEMA]₀Is 27mmol L^-1、[NaPS]₀0.71mmol L^-1，[DMC]₀12.8mmol L^-1、[Fe^II/EDTA]₀10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.00 × 10⁷。

Example 3:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.4mol L^-1、[DMAEMA]₀Is 21mmol L^-1、[NaPS]₀0.71mmol L^-1、[DMC]₀) 12.8mmol L^-1、[Fe^II/EDTA]₀10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.28 × 10⁷。

Example 4:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.4mol L^-1、[DMAEMA]₀Is 42mmol L^-1、[NaPS]₀0.71mmol L^-1、[DMC]₀12.8mmol L^-1、[Fe^II/EDTA]₀10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.13 × 10⁷。

Example 5:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.4mol L^-1、[DMAEMA]₀Is 21mmol L^-1、[NaPS]₀0.71mmol L^-1、[DMC]₀8.5mmol L^-1、[Fe^II/EDTA]₀10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm measured by viscometry was 6.31X 10⁶。

Example 6:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀23mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、FeCl₃Initial concentration of EDTA (noted as [ Fe ]^Ⅲ/EDTA]₀Wherein [ Fe ]^Ⅲ]₀:[EDTA]₀Is fixed at an equivalent ratio of 1:1) of 11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity of the reaction solution gradually rises, the temperature rises continuously, after the monomer is completely convertedThe temperature of the reaction solution was kept constant for a short time and then gradually decreased. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.13 × 10⁷。

Example 7:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.8mol L^-1、[DMAEMA]₀Is 23mmol L^-1、[NaPS]₀0.77mmol L^-1、[DMC]₀Is 14.0mmol L^-1、[Fe^Ⅲ/EDTA]₀17.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.02 × 10⁷。

Example 8:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 17mmol L^-1、NaPS]₀1.17mmol L^-1、[DMC]₀Is 14.0mmol L^-1、[Fe^Ⅲ/EDTA]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 8.23 × 10⁶。

Example 9:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 35mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、CuSO₄·5H₂O/Me₆Starting concentration of TREN (noted as [ Cu ]^Ⅱ/Me₆TREN]₀In which [ Cu ]^Ⅱ]₀:[Me₆TREN]₀Is fixed at an equivalent ratio of 1:1) of 11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 3.30 × 10⁶。

Example 10:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 29mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Cu^Ⅱ/Me₆TREN]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring by viscosity method is 3.92 × 10⁶。

Example 11:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 23mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Cu^Ⅱ/Me₆TREN]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually rising after the monomer is completely convertedAnd (5) reducing. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm 5.68 × 10 determined by viscosity method⁶。

Example 12:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀) Is 4.9mol L^-1、[DMAEMA]₀Is 18mmol L^-1、[NaPS]₀) 0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Cu^Ⅱ/Me₆TREN]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.02 × 10⁷。

Example 13:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 12mmol L^-1、[NaPS]₀1.17mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Cu^Ⅱ/Me₆TREN]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 3.85 × 10⁶。

Example 14:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.4mol L^-1、[DMAEMA]₀Is 32mmol L^-1、[NaPS]₀0.71mmol L^-1，[DMC]₀12.8mmol L^-1、CuSO₄·5H₂O/PMDETA initial concentration (noted as [ Cu ]^Ⅱ/PMDETA]₀In which [ Cu ]^II]₀:[PMDETA]₀Is fixed at an equivalent ratio of 1:1) of 10.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm 7.45 × 10 determined by viscosity method⁶。

Example 15:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1Initial concentration of N, N-Diethylaminoethyl (DEAE) [ DEAE ]]₀) Is 37mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Fe^Ⅲ/EDTA]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm 5.57 × 10 determined by viscosity method⁶。

Example 16:

a total volume of 100mL of aqueous solution was prepared, wherein the initial concentration of AAm (noted as [ AAm ]]₀) Is 4.9mol L^-1、[DEAE]₀Is 29mmol L^-1、[NaPS]₀0.78mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Fe^Ⅲ/EDTA]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting at 35 deg.C, the viscosity and temperature of the reaction solution gradually rising, and the temperature of the reaction solution gradually falling after the monomer is completely converted and kept stable in a short time. Micelle to be reactedAfter 6h, the temperature is reduced to normal temperature, and the polymer is taken out to be tested. PAAm obtained by measuring with viscosity method is 6.09 × 10⁶。

Example 17:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 18mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Adding the materials into a plastic self-sealing bag, uniformly mixing, introducing argon to remove oxygen for 15min, and adding NaPS into the plastic self-sealing bag to obtain [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 3.39 × 10⁶。

Example 18:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 23mmol L^-1、[DMC]₀Was 14.1mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Mixing AAm, DMAEMA, DMC and FeCl₂EDTA is added into the plastic self-sealing bag and then is mixed evenly, argon is introduced to remove oxygen for 15min, and NaPS is added into the plastic self-sealing bag to ensure that [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 3.10 × 10⁶。

Example 19:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 18mmol L^-1、[DMDAAC]₀10.9mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Mixing AAm, DMAEMA, DMDAAC and FeCl₂EDTA is added into the plastic self-sealing bag and then is mixed evenly, argon is introduced to remove oxygen for 15min, and NaPS is added into the plastic self-sealing bag to ensure that [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 4.07 x 10⁶。

Example 20:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 3.9mol L^-1、[DMAEMA]₀Is 18mmol L^-1、[DMDAAC]₀10.9mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Mixing AAm, DMAEMA, DMDAAC and FeCl₂EDTA is added into the plastic self-sealing bag and then is mixed evenly, argon is introduced to remove oxygen for 15min, and NaPS is added into the plastic self-sealing bag to ensure that [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring by viscosity method is 3.08 × 10⁶。

Example 21:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 3.9mol L^-1、[DEAE]₀Is 22mmol L^-1、[DMDAAC]₀10.9mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Mixing AAm, DEAE, DMDAAC and FeCl₂EDTA is added into the plastic self-sealing bag and then mixed evenlyHomogenizing, introducing argon to remove oxygen for 15min, and adding NaPS into the plastic self-sealing bag to obtain [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 1.85 × 10⁶。

Example 22:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 3.9mol L^-1Initial concentration of Triethanolamine (TEOA) [ TEOA ]]₀) Is 22mmol L^-1、[DMDAAC]₀10.9mmol L^-1、[Fe^II/EDTA]₀11.0. mu. mol L^-1. Mixing AAm, TEOA, DMDAAC and FeCl₂EDTA is added into the plastic self-sealing bag and then is mixed evenly, argon is introduced to remove oxygen for 15min, and NaPS is added into the plastic self-sealing bag to ensure that [ NaPS]₀0.78mmol L^-1And after continuously deoxidizing for 15min, extruding to remove residual air in the self-sealing bag, and sealing. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring with viscosity method is 2.03 × 10⁶。

Example 23:

preparing an aqueous solution having a total volume of 100mL, wherein [ AAm]₀Is 4.9mol L^-1、[DMAEMA]₀Is 18mmol L^-1、[DMDAAC]₀10.9mmol L^-1、[Cu^Ⅱ/Me₆TREN]₀11.0. mu. mol L^-1. Mixing AAm, DMAEMA, DMDAAC and CuSO₄·H₂O/Me₆TREN is added into a plastic self-sealing bag and then mixed evenly, argon is introduced to remove oxygen for 15min, and NaPS is added into the plastic self-sealing bag to ensure that [ NaPS]₀0.78mmol L^-1Removing oxygen for 15min, and removing by squeezingAnd (5) sealing residual air in the self-sealing bag. Then reacting in water bath at 20 ℃, the viscosity of the reaction solution gradually rises, the temperature continuously rises, and the temperature of the reaction solution is kept stable for a short time and then gradually falls after the monomers are completely converted. And after the temperature of the reaction micelle is reduced to normal temperature after 6 hours, taking out the polymer to be tested. PAAm obtained by measuring viscosity is 2.49 × 10⁶。

Claims (6)

1. A process for preparing high molecular weight polyacrylamide (PAAm), characterized in that: catalyzing persulfate-micromolecule aliphatic tertiary amine to initiate acrylamide (AAm) free radical polymerization in aqueous solution containing cationic monomers by using a transition metal salt complex catalyst to obtain high molecular weight PAAm;

(1) the transition metal salt complex catalyst comprises bivalent or trivalent iron salt (respectively marked as Fe)^IIOr Fe^III) Complexes with disodium edetate (denoted as Fe)^II/EDTANa₂Or Fe^III/EDTANa₂) Copper (II) salt (denoted as Cu)^II) With N, N, N' -pentamethyldivinyltriamine or tris [2- (N, N-dimethylamino) ethyl]Amine-forming complexes (respectively designated as Cu)^IIPer PMDETA and Cu^II/Me₆TREN)；

(2) The micromolecular aliphatic tertiary amine comprises N, N-diethylaminoethanol, triethanolamine and 2- (N, N-dimethylamino) ethyl methacrylate;

(3) the cationic monomer comprises methacryloyloxyethyl trimethyl ammonium chloride (DMC); dimethyldiallylammonium chloride, DADMAC.

2. The method of claim 1, wherein the AAm initial concentration is in the range of 3.8-5.0mol L^-1。

3. The method according to claim 1, wherein the concentration of the transition metal salt complex catalyst is in the range of 10.0-12.0 μmol L^-1。

4. The method of claim 1, wherein said fraction is a fraction ofThe concentration range of the aliphatic tertiary amine is 10.0-40.0mmol L^-1。

5. The method of claim 1, wherein the cationic monomer concentration is in the range of 8.0 to 15.0mmol L^-1。

6. The method of claim 1 wherein said high molecular weight PAAm has a viscosity average molecular weight in the range of 1.80X 10⁶-1.30×10⁷。