CN113461839A - Preparation method of Schiff base rare earth catalyst and application of Schiff base rare earth catalyst in bacteriostatic polyacrylamide flocculant - Google Patents
Preparation method of Schiff base rare earth catalyst and application of Schiff base rare earth catalyst in bacteriostatic polyacrylamide flocculant Download PDFInfo
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- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 111
- -1 Schiff base rare earth Chemical class 0.000 title claims abstract description 109
- 239000002262 Schiff base Substances 0.000 title claims abstract description 98
- 239000003054 catalyst Substances 0.000 title claims abstract description 62
- 238000002360 preparation method Methods 0.000 title claims abstract description 39
- 230000003385 bacteriostatic effect Effects 0.000 title claims abstract description 33
- 229920002401 polyacrylamide Polymers 0.000 title claims description 57
- 238000006243 chemical reaction Methods 0.000 claims abstract description 104
- 238000003756 stirring Methods 0.000 claims abstract description 46
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 38
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 38
- SMQUZDBALVYZAC-UHFFFAOYSA-N salicylaldehyde Chemical compound OC1=CC=CC=C1C=O SMQUZDBALVYZAC-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229960004909 aminosalicylic acid Drugs 0.000 claims abstract description 25
- 239000003446 ligand Substances 0.000 claims abstract description 25
- 150000004753 Schiff bases Chemical class 0.000 claims abstract description 20
- WUBBRNOQWQTFEX-UHFFFAOYSA-N 4-aminosalicylic acid Chemical compound NC1=CC=C(C(O)=O)C(O)=C1 WUBBRNOQWQTFEX-UHFFFAOYSA-N 0.000 claims abstract description 18
- OXSANYRLJHSQEP-UHFFFAOYSA-N 4-aminophthalic acid Chemical compound NC1=CC=C(C(O)=O)C(C(O)=O)=C1 OXSANYRLJHSQEP-UHFFFAOYSA-N 0.000 claims abstract description 17
- 238000001556 precipitation Methods 0.000 claims abstract description 16
- 238000010992 reflux Methods 0.000 claims abstract description 15
- 238000000967 suction filtration Methods 0.000 claims abstract description 15
- 238000001291 vacuum drying Methods 0.000 claims abstract description 15
- 238000004729 solvothermal method Methods 0.000 claims abstract description 8
- 239000007788 liquid Substances 0.000 claims description 34
- 239000003999 initiator Substances 0.000 claims description 29
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 28
- 238000001035 drying Methods 0.000 claims description 23
- 230000000844 anti-bacterial effect Effects 0.000 claims description 20
- 238000006116 polymerization reaction Methods 0.000 claims description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims description 14
- 239000012986 chain transfer agent Substances 0.000 claims description 13
- 239000006184 cosolvent Substances 0.000 claims description 13
- 239000002244 precipitate Substances 0.000 claims description 13
- 239000003381 stabilizer Substances 0.000 claims description 13
- 239000000725 suspension Substances 0.000 claims description 13
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 11
- 239000008367 deionised water Substances 0.000 claims description 11
- 229910021641 deionized water Inorganic materials 0.000 claims description 11
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 10
- 239000004202 carbamide Substances 0.000 claims description 10
- 230000000977 initiatory effect Effects 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 10
- XSQUKJJJFZCRTK-UHFFFAOYSA-N urea group Chemical group NC(=O)N XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 10
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 claims description 8
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 claims description 8
- 229940047670 sodium acrylate Drugs 0.000 claims description 8
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 7
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 7
- ZGTMUACCHSMWAC-UHFFFAOYSA-L EDTA disodium salt (anhydrous) Chemical group [Na+].[Na+].OC(=O)CN(CC([O-])=O)CCN(CC(O)=O)CC([O-])=O ZGTMUACCHSMWAC-UHFFFAOYSA-L 0.000 claims description 7
- 230000032683 aging Effects 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- ATINCSYRHURBSP-UHFFFAOYSA-K neodymium(iii) chloride Chemical compound Cl[Nd](Cl)Cl ATINCSYRHURBSP-UHFFFAOYSA-K 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- HYHCSLBZRBJJCH-UHFFFAOYSA-N sodium polysulfide Chemical group [Na+].S HYHCSLBZRBJJCH-UHFFFAOYSA-N 0.000 claims description 7
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 claims description 6
- 238000005469 granulation Methods 0.000 claims description 6
- 230000003179 granulation Effects 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 239000003109 Disodium ethylene diamine tetraacetate Substances 0.000 claims description 5
- KWYHDKDOAIKMQN-UHFFFAOYSA-N N,N,N',N'-tetramethylethylenediamine Chemical compound CN(C)CCN(C)C KWYHDKDOAIKMQN-UHFFFAOYSA-N 0.000 claims description 5
- 235000019301 disodium ethylene diamine tetraacetate Nutrition 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 5
- 239000004280 Sodium formate Substances 0.000 claims description 4
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- WFIZEGIEIOHZCP-UHFFFAOYSA-M potassium formate Chemical compound [K+].[O-]C=O WFIZEGIEIOHZCP-UHFFFAOYSA-M 0.000 claims description 4
- HLBBKKJFGFRGMU-UHFFFAOYSA-M sodium formate Chemical compound [Na+].[O-]C=O HLBBKKJFGFRGMU-UHFFFAOYSA-M 0.000 claims description 4
- 235000019254 sodium formate Nutrition 0.000 claims description 4
- BYDYILQCRDXHLB-UHFFFAOYSA-N 3,5-dimethylpyridine-2-carbaldehyde Chemical compound CC1=CN=C(C=O)C(C)=C1 BYDYILQCRDXHLB-UHFFFAOYSA-N 0.000 claims description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 3
- LSDPWZHWYPCBBB-UHFFFAOYSA-N Methanethiol Chemical compound SC LSDPWZHWYPCBBB-UHFFFAOYSA-N 0.000 claims description 3
- VYLVYHXQOHJDJL-UHFFFAOYSA-K cerium trichloride Chemical compound Cl[Ce](Cl)Cl VYLVYHXQOHJDJL-UHFFFAOYSA-K 0.000 claims description 3
- VGBWDOLBWVJTRZ-UHFFFAOYSA-K cerium(3+);triacetate Chemical compound [Ce+3].CC([O-])=O.CC([O-])=O.CC([O-])=O VGBWDOLBWVJTRZ-UHFFFAOYSA-K 0.000 claims description 3
- JLRJWBUSTKIQQH-UHFFFAOYSA-K lanthanum(3+);triacetate Chemical compound [La+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JLRJWBUSTKIQQH-UHFFFAOYSA-K 0.000 claims description 3
- ICAKDTKJOYSXGC-UHFFFAOYSA-K lanthanum(iii) chloride Chemical compound Cl[La](Cl)Cl ICAKDTKJOYSXGC-UHFFFAOYSA-K 0.000 claims description 3
- 239000011259 mixed solution Substances 0.000 claims 1
- 230000016615 flocculation Effects 0.000 abstract description 12
- 238000005189 flocculation Methods 0.000 abstract description 12
- 150000001450 anions Chemical class 0.000 abstract description 6
- 230000001988 toxicity Effects 0.000 abstract 1
- 231100000419 toxicity Toxicity 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 19
- 238000012360 testing method Methods 0.000 description 18
- 230000000052 comparative effect Effects 0.000 description 13
- 239000000047 product Substances 0.000 description 10
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 8
- 239000000178 monomer Substances 0.000 description 7
- 239000000243 solution Substances 0.000 description 7
- 239000002351 wastewater Substances 0.000 description 7
- 239000003795 chemical substances by application Substances 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- 239000010865 sewage Substances 0.000 description 5
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 4
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 4
- 210000004027 cell Anatomy 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 4
- 238000005303 weighing Methods 0.000 description 4
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- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000007036 catalytic synthesis reaction Methods 0.000 description 3
- 239000002270 dispersing agent Substances 0.000 description 3
- 239000013110 organic ligand Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 241000588724 Escherichia coli Species 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 2
- 241000191967 Staphylococcus aureus Species 0.000 description 2
- 238000007112 amidation reaction Methods 0.000 description 2
- 125000000129 anionic group Chemical group 0.000 description 2
- XEVRDFDBXJMZFG-UHFFFAOYSA-N carbonyl dihydrazine Chemical compound NNC(=O)NN XEVRDFDBXJMZFG-UHFFFAOYSA-N 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 210000000170 cell membrane Anatomy 0.000 description 2
- 230000019522 cellular metabolic process Effects 0.000 description 2
- 235000019441 ethanol Nutrition 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 229920006158 high molecular weight polymer Polymers 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
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- 230000002503 metabolic effect Effects 0.000 description 2
- 230000000813 microbial effect Effects 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 150000003904 phospholipids Chemical class 0.000 description 2
- 230000001766 physiological effect Effects 0.000 description 2
- 229920002647 polyamide Polymers 0.000 description 2
- 238000000710 polymer precipitation Methods 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 230000036632 reaction speed Effects 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 206010028980 Neoplasm Diseases 0.000 description 1
- 241000700605 Viruses Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000004071 biological effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000000701 coagulant Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- 150000002466 imines Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000000338 in vitro Methods 0.000 description 1
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- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
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- 239000000126 substance Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F4/00—Polymerisation catalysts
- C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
- C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
- C08F4/52—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides selected from boron, aluminium, gallium, indium, thallium or rare earths
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
- C02F1/56—Macromolecular compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic Table
- C07F5/003—Compounds containing elements of Groups 3 or 13 of the Periodic Table without C-Metal linkages
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/52—Amides or imides
- C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
- C08F220/56—Acrylamide; Methacrylamide
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Polymers & Plastics (AREA)
- Engineering & Computer Science (AREA)
- Medicinal Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Hydrology & Water Resources (AREA)
- Water Supply & Treatment (AREA)
- Environmental & Geological Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Materials Engineering (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
The invention discloses a preparation method of a Schiff base rare earth catalyst, which is characterized by comprising the following steps of: (1) dissolving salicylaldehyde in absolute ethyl alcohol, adding p-aminosalicylic acid, and carrying out water bath reflux reaction at the temperature of 60-70 ℃; (2) continuously adding 4-aminophthalic acid, stirring uniformly, and carrying out reflux reaction in a water bath at the temperature of 60-70 ℃ for 3-5 h to obtain a Schiff base ligand; (3) and adding the obtained Schiff base ligand and rare earth salt into hot absolute ethyl alcohol at the temperature of 55-60 ℃, uniformly stirring, carrying out solvothermal reaction at the temperature of 60-95 ℃ for 3-6 h, then carrying out precipitation, suction filtration and rinsing, and carrying out vacuum drying at the temperature of 30 ℃ for 0.5h to obtain the Schiff base ligand. The novel Schiff base rare earth catalyst has lower toxicity, has less harm to human bodies and the environment, and the prepared anion bacteriostatic flocculant has better flocculation and bacteriostatic effects, can effectively remove chromaticity and shorten flocculation time, has good bacteriostatic activity, is convenient to use, and has wide application prospect.
Description
Technical Field
The invention relates to the field of rare earth catalysts and polymer synthesis, in particular to a preparation method of a Schiff base rare earth catalyst and application of the Schiff base rare earth catalyst in a bacteriostatic polyacrylamide flocculant.
Background
With the rapid development of industrial economy in China, the consumption market of Polyacrylamide (PAM) products is continuously growing. However, with the continuous improvement of the environmental protection requirement in China, the consumption of polyacrylamide in the field of water treatment is increasing year by year, and the polyacrylamide product as a polymeric flocculant can stabilize a system or flocculate and precipitate particles in the system, and has important application in the fields of water treatment, oil exploitation industry, paper making and the like. At present, polyacrylamide is mainly used as a coagulant aid and a flocculant in water supply treatment and sewage treatment, but the product mainly has the common problems of large flocculant dosage and large influence of water quality on flocculation effect, and the demand of functional polyacrylamide products with antibacterial effect is increased. In addition, in the polymerization process of the acrylamide aqueous solution, the addition of some common organic solvent catalysts or reagents, such as alcohols, acetone, dimethyl sulfoxide and the like, affects the polymerization kinetics of acrylamide, even the addition of some solvents can cause polymer insolubilization or precipitation, and due to the change of a polymerization medium, a series of properties of a system are changed, so that the conversion rate of the polymer is low, the monomer content of the acrylamide is high, the quality of the polymer is unstable, the viscosity of a polyacrylamide product is affected, and the effects of filtration aiding, decoloration and flocculation are further affected. Meanwhile, the dosage of the initiator has a crucial influence on the molecular weight and viscosity of polyacrylamide, when the amount of the initiator is too small, the monomer cannot be fully polymerized, the reaction speed is slow, the efficiency is low, and the molecular weight distribution of the obtained polymer is not uniform or an insoluble phenomenon is generated; when the initiator is too much, a large amount of free radicals are generated in a short time, and the mutual collision of the free radicals accelerates the termination reaction, so that the number of monomers used for molecular chain growth is small, a high molecular weight polymer cannot be obtained, the reaction speed is too high due to the excessive initiator, a large amount of heat is generated in the reaction system instantly, the temperature of the reaction system is increased rapidly, and the generation of the high molecular weight polymer is also influenced. Therefore, how to prepare the antibacterial polyacrylamide flocculant with high molecular weight, high viscosity, high conversion rate, low dosage and antibacterial and bacteriostatic effects has important significance.
The Schiff base rare earth complex mainly refers to a complex formed by an organic ligand containing imine or azomethine groups and rare earth metal ions, and researches show that the Schiff base rare earth complex has the characteristics of strong bactericidal capacity and wide antibacterial spectrum, and also has the biological activities of resisting tumors and viruses, but has a few reports on the aspect of catalyzing the synthesis of polyacrylamide.
Based on the above, the invention synthesizes the bis-schiff base rare earth complex by using salicylaldehyde, p-aminosalicylic acid, 4-aminophthalic acid and soluble rare earth salt for the first time, and is further applied to the catalytic synthesis of polyacrylamide, under the initiation action of a small amount of initiator, the schiff base rare earth catalyst can realize the full polymerization of monomers, has high conversion rate, high product yield, high molecular weight and high viscosity, simultaneously has high-efficiency antibacterial and bacteriostatic effects, low dosage and stable flocculation effect, is suitable for sewage treatment, and can also be used as a profile control agent and a dispersing agent.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a preparation method of a Schiff base rare earth catalyst and application of the Schiff base rare earth catalyst in a bacteriostatic polyacrylamide flocculant.
The technical scheme of the invention is summarized as follows:
a preparation method of a Schiff base rare earth catalyst comprises the following steps:
(1) dissolving salicylaldehyde in absolute ethyl alcohol, adding p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at the temperature of 60-70 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) adding 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, performing reflux reaction in a water bath at 60-70 ℃ for 3-5 h, performing precipitation, suction filtration and rinsing after the reaction is finished, performing vacuum drying at 30 ℃ for 0.5h, recrystallizing, and drying to obtain a Schiff base ligand;
(3) and (3) adding the Schiff base ligand and the rare earth salt obtained in the step (2) into hot absolute ethyl alcohol at the temperature of 55-60 ℃, uniformly stirring, moving to a reaction kettle, carrying out solvothermal reaction at the temperature of 60-95 ℃ for 3-6 h, carrying out precipitation, suction filtration and rinsing after the reaction is finished, and carrying out vacuum drying at the temperature of 30 ℃ for 0.5h to obtain the Schiff base rare earth catalyst.
Preferably, the rare earth salt comprises one or more of rare earth acetate and rare earth chloride.
Preferably, the rare earth acetate comprises one or more of lanthanum acetate, cerium acetate and neodymium acetate; the rare earth chloride salt comprises one or more of lanthanum chloride, cerium chloride and neodymium chloride.
Preferably, the dosage ratio of the salicylaldehyde, the p-aminosalicylic acid, the 4-aminophthalic acid and the absolute ethyl alcohol is (0.02-0.04) mol, (0.015-0.02) mol, (0.005-0.01) mol, (40-60) mL.
Preferably, the dosage proportion of the Schiff base ligand, the rare earth salt and the hot absolute ethyl alcohol is 1.064g (0.0026-0.004) mol:150 mL.
The invention further provides application of the Schiff base rare earth catalyst prepared by the preparation method in a bacteriostatic polyacrylamide flocculant.
The application method comprises the following steps:
(1) uniformly mixing acrylamide, sodium acrylate and deionized water according to the mass ratio of (1.5-2) to (1) (8.5-22) to prepare mixed feed liquid;
(2) adding the Schiff base rare earth catalyst, the cosolvent and the stabilizer prepared by the preparation method into the mixed material liquid prepared in the step (1), uniformly stirring, transferring into a reaction kettle, and dropwise adding acrylic acid to adjust the pH value to 6-7 to obtain a reaction system I;
(3) adding an initiator and an auxiliary initiator into the reaction system I obtained in the step (2), introducing pure nitrogen for 30-60 min, and adjusting the temperature of the system to 10-15 ℃ to obtain a reaction system II;
(4) adding a chain transfer agent into the reaction system II obtained in the step (3), stirring for 3-5 min, adding a chain terminator, introducing nitrogen for 1-2 min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, sealing the reaction kettle, and initiating a polymerization reaction for 2-6 h;
(5) and after the reaction is finished, aging for 2 hours at the temperature of 80-85 ℃, and preparing the antibacterial polyacrylamide flocculant after mechanical granulation, drying and crushing.
Preferably, the cosolvent is urea; the stabilizer is disodium ethylene diamine tetraacetate; the initiator is one of azodiisobutyramidine hydrochloride and ammonium persulfate-sodium bisulfite systems; the auxiliary initiator is one of triethanolamine, aluminum chloride and tetramethyl ethylene diamine; the chain transfer agent is one of sodium formate, isopropanol, mercaptan, 1, 4-butanediol and potassium formate; the chain terminator is sodium polysulfide.
Preferably, the amount of the Schiff base rare earth catalyst is 0.03-0.05% of the mass of the mixed feed liquid; the using amount of the cosolvent urea is 1-1.5% of the mass of the mixed feed liquid; the using amount of the stabilizer is 0.004-0.006% of the mass of the mixed feed liquid; the amount of the initiator is 0.004-0.006% of the mass of the mixed feed liquid; the amount of the auxiliary initiator is 0.08-0.1% of the mass of the mixed material liquid; the dosage of the chain transfer agent is 0.0008-0.002% of the mass of the mixed feed liquid; the amount of the chain terminator is 0.0008-0.001% of the mass of the mixed material liquid.
Preferably, the drying time is 5-6 h, and the drying temperature is 45-50 ℃.
The invention has the beneficial effects that:
1. the invention adopts salicylaldehyde, p-aminosalicylic acid, 4-aminophthalic acid and soluble rare earth salt to synthesize the bis-Schiff base rare earth complex for the first time, and is further applied to the catalytic synthesis of polyacrylamide, under the initiation action of a small amount of initiator, the Schiff base rare earth catalyst can realize the full polymerization of monomers, and has the advantages of high conversion rate, high product yield, high molecular weight, high viscosity, high efficient antibacterial and bacteriostatic effects, low dosage, stable flocculation effect, suitability for sewage treatment, and capability of being used as a profile control agent and a dispersing agent.
2. The Schiff base rare earth complex replaces the traditional organic solvent catalyst, the reaction process is stable, the phenomena of sudden polymerization, polymer precipitation and the like are avoided, and the reaction process is more stable and easy to control.
3. The Schiff base rare earth complex can be used as a catalyst and also can be used as a reactant to be grafted into a polyacrylamide long-chain structure, so that the polyacrylamide flocculant has an antibacterial and bacteriostatic effect, the salicylaldehyde p-aminosalicylic acid Schiff base rare earth complex and the salicylaldehyde (4-aminophthalic acid) Schiff base rare earth complex have-COOH functional groups, and are subjected to amidation reaction with diamino urea to form a salicylaldehyde p-aminosalicylic acid Schiff base rare earth complex-urea-acrylic acid polycondensate or a salicylaldehyde (4-aminophthalic acid) Schiff base rare earth complex-urea-acrylic acid polycondensate which is formed by connecting polyamide groups, and then the salicylaldehyde p-aminosalicylic acid Schiff base rare earth complex-urea-acrylic acid polycondensate is connected into a polyacrylamide long chain by utilizing-C-in the polycondensate, and part of positive charges in rare earth metal ions in the complexes are transferred into an organic ligand structure, generating electrons to produce delocalization effect, so that the polarity of rare earth metal ions is reduced, and the lipid solubility of the rare earth metal ions is enhanced, therefore, the rare earth metal ions can penetrate the phospholipid layer of microbial cell membrane to influence the normal metabolism of cells, and simultaneously, the rare earth metal ions have Ca antagonism2+Effect of (1), and Ca2+Is an ion for maintaining normal physiological activities of cells, so that normal metabolic activities of the cells are interfered, and further, the microorganisms are killed, and the effects of resisting and inhibiting bacteria are achieved.
Drawings
The drawings are included to provide a further understanding of the disclosure, and are not to be construed as limiting the disclosure.
FIG. 1 is a flow chart of a preparation method of the Schiff base rare earth catalyst of the invention;
FIG. 2 is a flow chart of the application of the Schiff base rare earth catalyst in the bacteriostatic polyacrylamide flocculant;
FIG. 3 is an infrared spectrum of the Schiff base rare earth catalyst prepared in example 1;
FIG. 4 is a graph showing the effect of treating a water sample in test example 1 with the flocculant prepared in example 1;
FIG. 5 is a graph showing the effect of treating a water sample in Experimental example 2 by treating a flocculant prepared in example 2;
FIG. 6 is a graph showing the effect of treating the water sample in Experimental example 3 with the flocculant prepared in example 3.
Detailed Description
The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.
The invention provides a preparation method of a Schiff base rare earth catalyst, which comprises the following steps:
(1) dissolving salicylaldehyde in absolute ethyl alcohol, adding p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at the temperature of 60-70 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) adding 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, carrying out reflux reaction in a water bath at 60-70 ℃ for 3-5 h, carrying out precipitation suction filtration after the reaction is finished, rinsing for 5 times by using absolute ethyl alcohol, drying in a vacuum drying oven at 30 ℃ for 0.5h, recrystallizing by using absolute ethyl alcohol, and drying to obtain a salicylaldehyde-condensed p-aminosalicylic acid/4-aminophthalic acid Schiff base ligand;
the dosage proportion of the salicylaldehyde, the p-aminosalicylic acid, the 4-aminophthalic acid and the absolute ethyl alcohol is (0.02-0.04) mol, (0.015-0.02) mol, (0.005-0.01) mol, (40-60) mL;
(3) adding the Schiff base ligand and the rare earth salt obtained in the step (2) into hot absolute ethyl alcohol at 55-60 ℃, uniformly stirring, controlling the dosage ratio of the Schiff base ligand to the rare earth salt to the hot absolute ethyl alcohol to be 1.064g (0.0026-0.004) mol:150mL, moving the Schiff base ligand to a reaction kettle, carrying out solvothermal reaction at 60-95 ℃ for 3-6 h, carrying out precipitation suction filtration after the reaction is finished, rinsing the solution for 5 times by using the absolute ethyl alcohol, and carrying out vacuum drying at 30 ℃ to obtain yellow precipitate for 0.5h, thus obtaining the Schiff base rare earth catalyst;
the rare earth salt comprises one or more of rare earth acetate and rare earth chloride; the rare earth acetate comprises one or more of lanthanum acetate, cerium acetate and neodymium acetate; the rare earth chloride salt comprises one or more of lanthanum chloride, cerium chloride and neodymium chloride.
The invention further provides application of the Schiff base rare earth catalyst prepared by the preparation method in a bacteriostatic polyacrylamide flocculant.
The application method comprises the following steps:
(1) uniformly mixing acrylamide, sodium acrylate and deionized water according to the mass ratio of (1.5-2) to (1) (8.5-22), and controlling the total mass of the acrylamide, the sodium acrylate and the deionized water to be 1500g to prepare mixed feed liquid;
(2) adding the Schiff base rare earth catalyst, the cosolvent and the stabilizer prepared by the preparation method into the mixed material liquid prepared in the step (1), uniformly stirring, transferring into a reaction kettle, and dropwise adding acrylic acid to adjust the pH value to 6-7 to obtain a reaction system I;
(3) adding an initiator and an auxiliary initiator into the reaction system I obtained in the step (2), introducing pure nitrogen for 30-60 min, and adjusting the temperature of the system to 10-15 ℃ to obtain a reaction system II;
(4) adding a chain transfer agent into the reaction system II obtained in the step (3), stirring for 3-5 min, adding a chain terminator, introducing nitrogen for 1-2 min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, sealing the reaction kettle, and initiating a polymerization reaction for 2-6 h;
(5) and after the reaction is finished, aging at 80-85 ℃ for 2h, mechanically granulating, drying at 45-50 ℃ for 5-6 h, and crushing to obtain the antibacterial polyacrylamide flocculant.
The cosolvent is urea; the stabilizer is disodium ethylene diamine tetraacetate; the initiator is one of azodiisobutyramidine hydrochloride and ammonium persulfate-sodium bisulfite systems; the auxiliary initiator is one of triethanolamine, aluminum chloride and tetramethyl ethylene diamine; the chain transfer agent is one of sodium formate, isopropanol, mercaptan, 1, 4-butanediol and potassium formate; the chain terminator is sodium polysulfide.
The dosage of the Schiff base rare earth catalyst is 0.03-0.05% of the mass of the mixed feed liquid, namely 0.45-0.75 g; the amount of the cosolvent urea is 1-1.5% of the mass of the mixed feed liquid, namely 15-22.5 g; the dosage of the stabilizer is 0.004-0.006 percent of the mass of the mixed feed liquid, namely 0.06-0.09 g; the amount of the initiator is 0.004-0.006% of the mass of the mixed feed liquid, namely 0.06-0.09 g; the dosage of the auxiliary initiator is 0.08-0.1% of the mass of the mixed feed liquid, namely 1.2-1.5 g; the dosage of the chain transfer agent is 0.0008-0.002% of the mass of the mixed feed liquid, namely 0.012-0.03 g; the amount of the chain terminator is 0.0008-0.001% of the mass of the mixed liquid, namely 0.012-0.015 g.
Example 1
A preparation method of a Schiff base rare earth catalyst comprises the following steps:
(1) dissolving 0.04mol of salicylaldehyde in 60mL of absolute ethyl alcohol, adding 0.02mol of p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at 65 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) continuously adding 0.01mol of 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, carrying out water bath reflux reaction at 65 ℃ for 3h, carrying out precipitation suction filtration after the reaction is finished, rinsing for 5 times by using absolute ethyl alcohol, drying in a vacuum drying oven at 30 ℃ for 0.5h, recrystallizing by using absolute ethyl alcohol, and drying to obtain a salicylaldehyde-condensed p-aminosalicylic acid/4-aminophthalic acid Schiff base ligand;
(3) weighing 1.064g of Schiff base ligand obtained in the step (2), sequentially adding the Schiff base ligand and 0.004mol of anhydrous neodymium chloride into 150mL of hot anhydrous ethanol at 55 ℃, uniformly stirring, moving into a reaction kettle, carrying out solvothermal reaction for 6h at 60 ℃, carrying out precipitation and suction filtration after the reaction is finished, rinsing for 5 times by using the anhydrous ethanol, and carrying out vacuum drying at 30 ℃ to obtain yellow precipitate for 0.5h to obtain the Schiff base rare earth catalyst;
the obtained product has an infrared spectrum measured by FTIR (KBr) tabletting method, as shown in FIG. 3, showing 1647cm-1The absorption peak indicates that the C ═ N group coordinated to neodymium.
The application of the Schiff base rare earth catalyst in the bacteriostatic polyacrylamide flocculant, and the preparation method of the bacteriostatic polyacrylamide flocculant comprises the following steps:
(1) uniformly mixing 226g of acrylamide, 130g of sodium acrylate and 1144g of deionized water to prepare a mixed feed liquid;
(2) adding 0.45g of Schiff base rare earth catalyst, 15g of cosolvent urea and 0.06g of stabilizer ethylenediaminetetraacetic acid disodium salt into the mixed feed liquid prepared in the step (1), uniformly stirring, moving to a reaction kettle with the volume of 2L, and dropwise adding acrylic acid to adjust the pH value to 6 to obtain a reaction system I;
(3) adding 0.045g of ammonium persulfate, 0.045g of sodium bisulfite and 1.2g of auxiliary initiator aluminum chloride into the reaction system I obtained in the step (2), introducing pure nitrogen for 40min, and adjusting the temperature of the system to 10 ℃ to obtain a reaction system II;
(4) adding 0.012g of chain transfer agent sodium formate into the reaction system II obtained in the step (3), stirring for 3min, adding 0.012g of chain termination agent sodium polysulfide, continuously introducing nitrogen for 2min to ensure that the oxygen content of the reaction system is less than or equal to 0.2%, then sealing the reaction kettle, and initiating a polymerization reaction for 2 h;
(5) after the reaction is finished, aging is carried out for 2h at 80 ℃, mechanical granulation is carried out, drying is carried out for 5h at 45 ℃, and crushing is carried out, thus obtaining the antibacterial polyacrylamide flocculant.
Example 2
A preparation method of a Schiff base rare earth catalyst comprises the following steps:
(1) dissolving 0.02mol of salicylaldehyde in 40mL of absolute ethyl alcohol, adding 0.015mol of p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at 70 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) continuously adding 0.005mol of 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, carrying out reflux reaction in a water bath at 70 ℃ for 5h, carrying out precipitation suction filtration after the reaction is finished, rinsing for 5 times by using absolute ethyl alcohol, drying in a vacuum drying oven at 30 ℃ for 0.5h, recrystallizing by using absolute ethyl alcohol, and drying to obtain a salicylaldehyde-condensed p-aminosalicylic acid/4-aminophthalic acid Schiff base ligand;
(3) weighing 1.064g of Schiff base ligand obtained in the step (2), sequentially adding the Schiff base ligand and 0.0026mol of anhydrous neodymium chloride into 150mL of hot anhydrous ethanol at 60 ℃, uniformly stirring, moving into a reaction kettle, carrying out solvothermal reaction for 3h at 95 ℃, carrying out precipitation and suction filtration after the reaction is finished, rinsing for 5 times by using the anhydrous ethanol, and carrying out vacuum drying at 30 ℃ to obtain yellow precipitate for 0.5h to obtain the Schiff base rare earth catalyst;
the application of the Schiff base rare earth catalyst in the bacteriostatic polyacrylamide flocculant, and the preparation method of the bacteriostatic polyacrylamide flocculant comprises the following steps:
(1) uniformly mixing 155g of acrylamide, 103g of sodium acrylate and 1242g of deionized water to prepare a mixed feed liquid;
(2) adding 0.75g of Schiff base rare earth catalyst, 22.5g of cosolvent urea and 0.09g of stabilizer disodium ethylene diamine tetraacetate into the mixed feed liquid prepared in the step (1), uniformly stirring, moving into a reaction kettle with the volume of 2L, and dropwise adding acrylic acid to adjust the pH value to 7 to obtain a reaction system I;
(3) adding 0.05g of ammonium persulfate, 0.01g of sodium bisulfite and 1.5g of triethanolamine as an auxiliary initiator into the reaction system I obtained in the step (2), introducing pure nitrogen for 60min, and adjusting the temperature of the system to 15 ℃ to obtain a reaction system II;
(4) adding 0.03g of chain transfer agent potassium formate into the reaction system II obtained in the step (3), stirring for 3min, adding 0.015g of chain terminator sodium polysulfide, continuously introducing nitrogen for 2min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, sealing the reaction kettle, and initiating a polymerization reaction, wherein the reaction time is 6 h;
(5) after the reaction is finished, aging is carried out for 2h at 85 ℃, mechanical granulation is carried out, drying is carried out for 6h at 50 ℃, and crushing is carried out, thus obtaining the antibacterial polyacrylamide flocculant.
Example 3
A preparation method of a Schiff base rare earth catalyst comprises the following steps:
(1) dissolving 0.03mol of salicylaldehyde in 50mL of absolute ethyl alcohol, adding 0.015mol of p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at 65 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) continuously adding 0.01mol of 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, carrying out water bath reflux reaction at 65 ℃ for 4h, carrying out precipitation suction filtration after the reaction is finished, rinsing for 5 times by using absolute ethyl alcohol, drying in a vacuum drying oven at 30 ℃ for 0.5h, recrystallizing by using absolute ethyl alcohol, and drying to obtain a salicylaldehyde-condensed p-aminosalicylic acid/4-aminophthalic acid Schiff base ligand;
(3) weighing 1.064g of Schiff base ligand obtained in the step (2), sequentially adding the Schiff base ligand and 0.0026mol of anhydrous neodymium chloride into 150mL of hot absolute ethyl alcohol at 58 ℃, uniformly stirring, transferring into a reaction kettle, carrying out solvothermal reaction for 4h at 75 ℃, carrying out precipitation suction filtration after the reaction is finished, rinsing for 5 times by using the anhydrous ethyl alcohol, and carrying out vacuum drying at 30 ℃ to obtain a yellow precipitate for 0.5h to obtain the Schiff base rare earth catalyst;
the application of the Schiff base rare earth catalyst in the bacteriostatic polyacrylamide flocculant, and the preparation method of the bacteriostatic polyacrylamide flocculant comprises the following steps:
(1) uniformly mixing 120g of acrylamide, 60g of sodium acrylate and 1320g of deionized water to prepare a mixed feed liquid;
(2) adding 0.55g of Schiff base rare earth catalyst, 20g of cosolvent urea and 0.08g of stabilizer disodium ethylenediamine tetraacetic acid into the mixed feed liquid prepared in the step (1), uniformly stirring, moving to a reaction kettle with the volume of 2L, and dropwise adding acrylic acid to adjust the pH value to 6.5 to obtain a reaction system I;
(3) adding 0.047g of ammonium persulfate, 0.02g of sodium bisulfite and 1.3g of auxiliary initiator tetramethyl ethylene diamine into the reaction system I obtained in the step (2), introducing pure nitrogen for 60min, and adjusting the temperature of the system to 12 ℃ to obtain a reaction system II;
(4) adding 0.02g of chain transfer agent isopropanol into the reaction system II obtained in the step (3), stirring for 5min, adding 0.013g of chain terminator sodium polysulfide, continuously introducing nitrogen for 2min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, closing the reaction kettle, and initiating a polymerization reaction, wherein the reaction time is 5 h;
(5) after the reaction is finished, aging is carried out for 2h at 80 ℃, mechanical granulation is carried out, drying is carried out for 6h at 50 ℃, and crushing is carried out, thus obtaining the antibacterial polyacrylamide flocculant.
Comparative example 1: the preparation method of the polyacrylamide flocculant in the embodiment 1 has the same steps as the preparation method of the polyacrylamide flocculant in the embodiment 1, and is different in that the Schiff base rare earth catalyst in the embodiment 1 is replaced by a salicylaldehyde-condensed p-aminosalicylic acid Schiff base rare earth catalyst in the preparation process, and the preparation method of the Schiff base rare earth catalyst comprises the following steps:
(1) dissolving 0.04mol of salicylaldehyde in 60mL of absolute ethyl alcohol, adding 0.03mol of p-aminosalicylic acid, uniformly stirring, carrying out water bath reflux reaction at 65 ℃ until an orange precipitate is not separated out any more, carrying out precipitation suction filtration, rinsing for 5 times by using the absolute ethyl alcohol, placing in a vacuum drying oven at 30 ℃ for drying for 0.5h, recrystallizing by using the absolute ethyl alcohol, and drying to obtain a salicylaldehyde p-aminosalicylic acid Schiff base ligand;
(2) weighing 1.064g of Schiff base ligand obtained in the step (1), sequentially adding the Schiff base ligand and 0.004mol of anhydrous neodymium chloride into 150mL of hot anhydrous ethanol at 55 ℃, uniformly stirring, moving into a reaction kettle, carrying out solvothermal reaction for 6h at 60 ℃, carrying out precipitation and suction filtration after the reaction is finished, rinsing for 5 times by using the anhydrous ethanol, and carrying out vacuum drying at 30 ℃ to obtain yellow precipitate for 0.5h to obtain the Schiff base rare earth catalyst;
comparative example 2: the preparation method of the polyacrylamide flocculant is the same as the preparation method of the polyacrylamide flocculant in the embodiment 1, and is different in that a Schiff base rare earth catalyst is not added in the preparation process; the preparation method of the polyacrylamide flocculant comprises the following steps:
(1) uniformly mixing 120g of acrylamide, 60g of sodium acrylate and 1320g of deionized water to prepare a mixed feed liquid;
(2) adding 20g of cosolvent urea and 0.08g of stabilizer disodium ethylene diamine tetraacetate into the mixed feed liquid prepared in the step (1), uniformly stirring, transferring into a reaction kettle with the volume of 2L, and dropwise adding acrylic acid to adjust the pH value to 6.5 to obtain a reaction system I;
(3) adding 0.047g of ammonium persulfate, 0.02g of sodium bisulfite and 1.3g of auxiliary initiator tetramethyl ethylene diamine into the reaction system I obtained in the step (2), introducing pure nitrogen for 60min, and adjusting the temperature of the system to 12 ℃ to obtain a reaction system II;
(4) adding 0.02g of chain transfer agent isopropanol into the reaction system II obtained in the step (3), stirring for 5min, adding 0.013g of chain terminator sodium polysulfide, continuously introducing nitrogen for 2min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, closing the reaction kettle, and initiating a polymerization reaction, wherein the reaction time is 5 h;
(5) after the reaction is finished, aging is carried out for 2h at 80 ℃, mechanical granulation is carried out, drying is carried out for 6h at 50 ℃, and crushing is carried out, thus obtaining the antibacterial polyacrylamide flocculant.
Comparative example 3: the preparation method of the polyacrylamide flocculant is the same as that of the preparation method of the polyacrylamide flocculant in the example 2, except that no Schiff base rare earth catalyst is added in the preparation process.
Comparative example 4: the preparation method of the polyacrylamide flocculant is the same as that of the preparation method of the polyacrylamide flocculant in the embodiment 3, except that no Schiff base rare earth catalyst is added in the preparation process.
Comparative example 5: and selecting a commercially available polyacrylamide flocculant.
Test example 1 Performance index measurement test
The polyacrylamides of examples 1-3 and comparative examples 1-5 were tested according to GB/T17514-:
TABLE 1
As can be seen from Table 1, the molecular weights and viscosities of examples 1-3 are obviously higher than those of comparative examples 1-5, and when the flocculant is used for sewage treatment, the flocculant is compact in floc and small in dosage, which proves that the Schiff base rare earth catalyst has important influence on the synthesis of polyacrylamide, the monomer conversion rate can be obviously improved, and the polymerization degree and yield of the product are high.
Test example 2 in vitro bacteriostatic test
0.5g of the polyacrylamide bacteriostatic flocculant prepared in example 1 was mixed with 500mL of deionized water in a beaker to prepare a mixture of 1: 1000, magnetically stirring for 1h, and then adding the solution with the concentration of 5X 10-5CFU/mL of E.coli and goldThe bacterial suspension of the staphylococcus aureus is used for a bacteriostatic circle experiment, the experiment is repeated and carried out for 3 times in parallel A, B, C, deionized water is used as a blank control experiment D, and the recorded data are shown in table 2.
TABLE 2
As can be seen from table 2, the inhibition zone of the anionic bacteriostatic flocculant in example 1 is significantly larger than that of the blank control experiment, which proves that the anionic bacteriostatic flocculant shows bacteriostatic activity on escherichia coli and staphylococcus aureus, and has a certain degree of antibacterial activity.
Test example 3 flocculation effect test
0.5g of polyacrylamide prepared in examples 1-3 and 0.5g of polyacrylamide prepared in comparative examples 1-5 are weighed and respectively added into 8 groups of 500mL deionized water to prepare a mixture of 1: 1000, the solutions prepared from the polyacrylamide of examples 1 to 3 were sequentially PA1 to PA3, and the solutions prepared from the polyacrylamide of comparative examples 1 to 5 were sequentially PA4 to PA 8.
Test example 3.1
Taking factory workshop wastewater of Anhui Feng original Biotechnology Limited company in Anhui city, respectively taking three 250mL beakers, respectively adding 200mL of wastewater into the three beakers, simultaneously adding 10mL of PA1, PA4 and PA5 into the three beakers, continuously stirring and mixing for 1min, standing for 10min, recording the settling time of flocs, the shape and the size of the flocs and the chromaticity of the solution, wherein the test results are shown in Table 3, and the apparent shape is shown in FIG. 4.
TABLE 3
| Name (R) | Settling time(s) | Color intensity | Morphology and size of flocs |
| PA1 | 38 | 50 | Big and compact wadding |
| PA4 | 62 | 80 | Larger and loose flocs |
| PA5 | 74 | 140 | Small and loose wadding |
As can be seen from the data in Table 3, compared with PA4 of comparative example 1 and PA5 of comparative example 2, the anion bacteriostatic flocculant PA1 prepared in example 1 has the advantages of obviously improved treatment effect, short flocculation time, effective chromaticity removal, large and compact generated flocs and convenience for subsequent filter press treatment.
Test example 3.2
Taking four 100mL test tubes from factory workshop wastewater of Anhui Tianrun chemical industry Co., Ltd, Anhui, Union, adding 50mL wastewater into each test tube, simultaneously adding 1mL of PA2, PA4, PA5 and PA6 into the four test tubes, continuously stirring and mixing for 1min, standing for 10min, and recording the settling time of flocs, the shape and the size of the flocs and the chromaticity of the solution, wherein the results are shown in Table 4, and the apparent shape is shown in FIG. 5.
TABLE 4
| Name (R) | Settling time(s) | Color intensity | Morphology and size of flocs |
| PA2 | 36 | 70 | Big and compact wadding |
| PA4 | 47 | 100 | Larger and loose flocs |
| PA5 | 83 | 180 | Small and loose wadding |
| PA6 | 65 | 160 | Small and loose wadding |
As can be seen from the data in Table 4, compared with PA4, PA5 and PA6 of comparative examples 1-3, the anion bacteriostatic flocculant PA2 prepared in example 2 has the advantages of obviously improved treatment effect, short flocculation time, effective chromaticity removal, large and compact generated flocs and convenience for subsequent filter press treatment.
Test example 3.3
Six 50mL test tubes were used for the wastewater of Nippon food Biotechnology Co., Ltd, 50mL of wastewater was added to each test tube, 1mL of PA3, PA4, PA5, PA6, PA7 and PA8 was added to the six test tubes at the same time, and after stirring and mixing for 1min, the test tubes were allowed to stand for 10min, and the time of floc sedimentation, the size of floc morphology and the solution chromaticity were recorded, and the results are shown in Table 5, and the apparent morphology is shown in FIG. 6.
TABLE 4
| Name (R) | Settling time(s) | Color intensity | Morphology and size of flocs |
| PA3 | 26 | 20 | Big and compact wadding |
| PA4 | 32 | 50 | Larger and loose flocs |
| PA5 | 43 | 90 | Small and loose wadding |
| PA6 | 48 | 90 | Small and loose wadding |
| PA7 | 51 | 110 | Small and loose wadding |
| PA8 | 46 | 129 | Small and loose flocs |
As can be seen from the data in Table 5, the chroma of the obtained wastewater is very deep and does not meet the environmental-friendly discharge standard, the chroma of a water sample is reduced by 60 percent after the water sample is treated by the original flocculating agent, and the subsequent treatment cost of the sludge is high after the water sample is subjected to plate-and-frame filter pressing. The anion bacteriostatic flocculant is used for treatment, the chromaticity is reduced to 20, the environment-friendly discharge standard is completely met, the solid slag settling time is short, the treatment efficiency is improved, and the subsequent treatment cost of the sludge is saved by more than 40%. Compared with PA4, PA5, PA6, PA7 and PA8 of comparative examples 1-5, the anion bacteriostatic flocculant PA3 prepared in the embodiment 3 has the advantages of obviously improved treatment effect, short flocculation time, effective chromaticity removal, large and compact generated flocs and convenience for subsequent filter press treatment.
In the embodiments 1 to 3, salicylaldehyde, p-aminosalicylic acid, 4-aminophthalic acid and soluble rare earth salt are firstly adopted to synthesize a bis-schiff base rare earth complex, and further applied to catalytic synthesis of polyacrylamide, and under the initiation action of a small amount of initiator, the schiff base rare earth catalyst can realize full polymerization of monomers, has high conversion rate, high product yield, high molecular weight and high viscosity, has high-efficiency antibacterial and bacteriostatic effects, is low in dosage and stable in flocculation effect, is suitable for sewage treatment, and can also be used as a profile control agent and a dispersing agent.
The Schiff base rare earth complex in the embodiment 1-3 replaces the traditional organic solvent catalyst, the reaction process is stable, phenomena such as sudden polymerization and polymer precipitation are avoided, and the reaction process is more stable and easy to control.
Examples 1 to 3, the schiff base rare earth complex can be used as a catalyst and a reactant and grafted to a polyacrylamide long-chain structure, so that the polyacrylamide flocculant has an antibacterial and bacteriostatic effect, the salicylaldehyde-aminosalicylic acid schiff base rare earth complex and the salicylaldehyde-condensed (4-aminophthalic acid) schiff base rare earth complex have a-COOH functional group, and through an amidation reaction with bis-aminourea, a salicylaldehyde-aminosalicylic acid schiff base rare earth complex-urea-acrylic acid polycondensate or a salicylaldehyde-condensed (4-aminophthalic acid) schiff base rare earth complex-urea-acrylic acid polycondensate formed by connecting a polyamide group is formed, and then-C-in the polycondensate is connected to a polyacrylamide long chain, because part of positive charges in rare earth metal ions in the complexes are transferred to an organic ligand structure, generating electrons to produce delocalization effect, so that the polarity of rare earth metal ions is reduced, and the lipid solubility of the rare earth metal ions is enhanced, therefore, the rare earth metal ions can penetrate the phospholipid layer of microbial cell membrane to influence the normal metabolism of cells, and simultaneously, the rare earth metal ions have Ca antagonism2+Effect of (1), and Ca2+Is an ion for maintaining normal physiological activities of cells, so that normal metabolic activities of the cells are interfered, and further, the microorganisms are killed, and the effects of resisting and inhibiting bacteria are achieved.
Based on the analysis, the novel rare earth catalyst prepared by the invention is used for synthesizing the anion antibacterial flocculant, has good antibacterial action, good flocculation effect and high treatment efficiency, can be widely used in the civil and industrial fields of water treatment and the like, and meanwhile, is energy-saving, environment-friendly, green and pollution-free, has no harm to human bodies, and is a relatively ideal water treatment agent.
While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.
Claims (10)
1. A preparation method of a Schiff base rare earth catalyst is characterized by comprising the following steps:
(1) dissolving salicylaldehyde in absolute ethyl alcohol, adding p-aminosalicylic acid, uniformly stirring, carrying out reflux reaction in a water bath at the temperature of 60-70 ℃ until an orange precipitate is not separated out any more, and magnetically stirring to obtain a suspension;
(2) adding 4-aminophthalic acid into the suspension obtained in the step (1), stirring uniformly, performing reflux reaction in a water bath at 60-70 ℃ for 3-5 h, performing precipitation, suction filtration and rinsing after the reaction is finished, performing vacuum drying at 30 ℃ for 0.5h, recrystallizing, and drying to obtain a Schiff base ligand;
(3) and (3) adding the Schiff base ligand and the rare earth salt obtained in the step (2) into hot absolute ethyl alcohol at the temperature of 55-60 ℃, uniformly stirring, moving to a reaction kettle, carrying out solvothermal reaction at the temperature of 60-95 ℃ for 3-6 h, carrying out precipitation, suction filtration and rinsing after the reaction is finished, and carrying out vacuum drying at the temperature of 30 ℃ for 0.5h to obtain the Schiff base rare earth catalyst.
2. The preparation method of the Schiff base rare earth catalyst, according to claim 1, wherein the rare earth salt comprises one or more of rare earth acetate and rare earth chloride.
3. The preparation method of the Schiff base rare earth catalyst, which is claimed in claim 2, wherein the rare earth acetate comprises one or more of lanthanum acetate, cerium acetate and neodymium acetate; the rare earth chloride salt comprises one or more of lanthanum chloride, cerium chloride and neodymium chloride.
4. The preparation method of the Schiff base rare earth catalyst according to claim 1, wherein in the steps (1) to (2), the dosage ratio of the salicylaldehyde, the p-aminosalicylic acid, the 4-aminophthalic acid and the absolute ethyl alcohol is (0.02-0.04) mol, (0.015-0.02) mol, (0.005-0.01) mol, (40-60) mL.
5. The preparation method of the Schiff base rare earth catalyst according to claim 1, wherein in the step (3), the dosage ratio of the Schiff base ligand, the rare earth salt and the hot absolute ethyl alcohol is 1.064g (0.0026-0.004) mol:150 mL.
6. The use of the Schiff base rare earth catalyst prepared by the preparation method according to any one of claims 1 to 5 in a bacteriostatic polyacrylamide flocculant.
7. The use according to claim 6, characterized in that the method of application comprises the steps of:
(1) uniformly mixing acrylamide, sodium acrylate and deionized water according to the mass ratio of (1.5-2) to (1) (8.5-22) to prepare mixed feed liquid;
(2) adding the Schiff base rare earth catalyst prepared by the preparation method of any one of claims 1 to 5, a cosolvent and a stabilizer into the mixed solution prepared in the step (1), uniformly stirring, transferring into a reaction kettle, and dropwise adding acrylic acid to adjust the pH value to 6-7 to obtain a reaction system I;
(3) adding an initiator and an auxiliary initiator into the reaction system I obtained in the step (2), introducing pure nitrogen for 30-60 min, and adjusting the temperature of the system to 10-15 ℃ to obtain a reaction system II;
(4) adding a chain transfer agent into the reaction system II obtained in the step (3), stirring for 3-5 min, adding a chain terminator, introducing nitrogen for 1-2 min to enable the oxygen content of the reaction system to be less than or equal to 0.2%, sealing the reaction kettle, and initiating a polymerization reaction for 2-6 h;
(5) and after the reaction is finished, aging for 2 hours at the temperature of 80-85 ℃, and preparing the antibacterial polyacrylamide flocculant after mechanical granulation, drying and crushing.
8. Use according to claim 7, wherein the co-solvent is urea; the stabilizer is disodium ethylene diamine tetraacetate; the initiator is one of azodiisobutyramidine hydrochloride and ammonium persulfate-sodium bisulfite systems; the auxiliary initiator is one of triethanolamine, aluminum chloride and tetramethyl ethylene diamine; the chain transfer agent is one of sodium formate, isopropanol, mercaptan, 1, 4-butanediol and potassium formate; the chain terminator is sodium polysulfide.
9. The application of claim 7, wherein the amount of the Schiff base rare earth catalyst is 0.03-0.05% of the mass of the mixed feed liquid; the using amount of the cosolvent urea is 1-1.5% of the mass of the mixed feed liquid; the using amount of the stabilizer is 0.004-0.006% of the mass of the mixed feed liquid; the amount of the initiator is 0.004-0.006% of the mass of the mixed feed liquid; the amount of the auxiliary initiator is 0.08-0.1% of the mass of the mixed material liquid; the dosage of the chain transfer agent is 0.0008-0.002% of the mass of the mixed feed liquid; the amount of the chain terminator is 0.0008-0.001% of the mass of the mixed material liquid.
10. The use according to claim 7, wherein the drying time is 5-6 h and the drying temperature is 45-50 ℃.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115304986A (en) * | 2022-08-25 | 2022-11-08 | 安徽中科思沃生物科技有限公司 | Shell powder-based photocatalytic self-cleaning mildew-proof interior wall coating and preparation method thereof |
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| 刘庆俭: "《有机化学（下册）》", 30 November 2018, 同济大学出版社 * |
| 韦军 等: "《高分子合成工艺学》", 28 February 2011, 华东理工大学出版社 * |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115304986A (en) * | 2022-08-25 | 2022-11-08 | 安徽中科思沃生物科技有限公司 | Shell powder-based photocatalytic self-cleaning mildew-proof interior wall coating and preparation method thereof |
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