2201 results about "Imine" patented technology

The invention belongs to the technical field of environmental protection, and provides a preparation method of an imine-modified functionalized mesoporous magnetic silicon dioxide nano material. The method comprises the following steps: synthesizing Fe3O4 magnetic nanoparticles in a Fe < 2 + > / Fe < 3 + > alkaline hydrolysis system through a coprecipitation method; then coating the magnetic nanoparticles with an amorphous silicon dioxide layer by taking TEOS (tetraethoxysilane) as a silicon source by adopting a sol-gel method, so as to prepare magnetic silicon coated nanoparticles; the prepared nano-particles are subjected to secondary silicon coating guided by a cetyl trimethyl ammonium bromide (CTAB) mesoporous template agent, and mesoporous magnetic silicon nano-particles are formed after calcination; and finally, carrying out surface amination modification on the mesoporous magnetic silicon nano-particles by utilizing an amino silane coupling agent, and then carrying out condensation reaction on the mesoporous magnetic silicon nano-particles and various aldehyde derivatives to construct imine bonds, so as to obtain the imine-modified functionalized mesoporous magnetic silicon dioxide nano-material. The imine-modified functionalized mesoporous magnetic silicon dioxide nano-material formed by the invention has the characteristics of efficient adsorption, rapid magnetic recovery and excellent environmental stability, and can effectively remove polystyrene micro-plastics and organic pollutants in a water body.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

The invention relates to the technical field of polyurethane acrylate, and particularly discloses dual-curing polyurethane acrylate resin and a preparation method thereof. Wherein the dual-curing polyurethane acrylate resin is prepared from the following raw materials: polyester polyol, polyether polyol, diisocyanate, hydroxyl acrylate, a chain extender, a photoinitiator, cardanol glycidyl ether, a polymerization inhibitor and modified nanoparticles. Wherein the citric acid and the polyethyleneimine are adopted to carry out synergistic modification on the nano particles, the dispersion stability of the nano particles is improved, so that the mechanical property of the resin is improved, the cardanol glycidyl ether and the photoinitiator generate a synergistic effect, and the resin can be quickly shaped through photocuring promoted by the photoinitiator; the cardanol glycidyl ether participates in the subsequent thermocuring reaction, so that the curing effect is improved, and the adhesive force between the film layer and the base material is enhanced.

The invention relates to the technical field of biochemical engineering, in particular to a method for preparing chiral alpha-trifluoromethyl alcohol by using imine reductase AtRedAm, trifluoromethyl ketone is reduced into corresponding chiral trifluoromethyl alcohol at an excellent conversion rate by using the imine reductase AtRedAm, and enantioselectivity is high. The reaction depends on an NADPH (Nicotinamide Adenine Dinucleotide Phosphate) coenzyme circulation system, 10% dimethyl sulfoxide is used as a reaction cosolvent, the reaction is carried out in a 100mM (pH = 7.5) phosphate buffer solution for 16 hours, the highest molar conversion rate reaches 99%, and the highest optical purity reaches 95%.

The invention relates to the field of copper-clad plates, and discloses a high-performance flame-retardant low-dielectric-loss copper-clad plate and a preparation method thereof.The copper-clad plate comprises epoxy resin, benzoxazine resin, composite filler, carboxyl-terminated nitrile rubber, an active diluent, a curing agent and the like; the composite filler is prepared by compounding flame-retardant modifier grafted graphene oxide and epoxy silane modified silicon dioxide hollow spheres; according to the flame-retardant modifier, boric acid and pentaerythritol are used for preparing a double-terminal hydroxyl boron-containing intermediate, then dichlorodiphenyl silane and phenylphosphonic dichloride react with hydroxyl groups at the two ends of the intermediate to prepare a flame-retardant intermediate, and amino silane and vanillic aldehyde react with chlorine atoms at the two ends of the intermediate to prepare an aldehyde modified flame-retardant intermediate; the copper-clad plate prepared by the preparation method disclosed by the invention is low in dielectric constant and dielectric loss, high in heat conductivity coefficient and good in flexibility, and also has excellent heat resistance and flame retardance.

The invention discloses a preparation method of a 3-micron ultrathin lithium battery copper foil. The preparation method comprises the following steps: preparing a copper sulfate electrolyte; a wetting agent, a brightening agent and a high resistance agent are added into the copper sulfate electrolyte, the high resistance agent is at least one of thiazolidinethione, polyethyleneimine, 2-mercaptobenzimidazole and ethylene thiourea, and a mixed additive is formed; polishing and grinding a cathode roller by adopting a flying wing wheel, and carrying out electrolytic treatment on the mixed additive through the polished and ground cathode roller to obtain a first-stage copper foil; and the first-stage copper foil is placed in a nitrogen furnace to be subjected to annealing treatment, and the 3-micron ultrathin lithium battery copper foil is obtained. The invention aims to solve the technical problems that in the prior art, edge tearing, foil breaking, warping, dark appearance oxidation and the like are prone to occurring in the production process of the ultrathin copper foil, the tensile strength and the ductility are difficult to consider at the same time, and stable mass production of the 3-micron copper foil is still difficult.

The invention discloses an omariglitazone intermediate as well as a synthesis method and application thereof, and belongs to the technical field of pharmaceutical chemistry synthesis. The invention provides a synthesis method of an omarigliflozin intermediate and application of the intermediate in synthesis of omarigliflozin. The key of the synthesis method provided by the invention lies in the deprotection process of polycyclic indole amide, nitrile groups are not hydrolyzed, indole carboxylic acid is generated with high selectivity, molecular lactamization is avoided in the condensation process with polycyclic imine B, and expensive amidation reagents such as HATU are not needed in the process, so that the synthesis method is simple and easy to implement. And the purpose of preparing omariglitazone with low cost and high yield is achieved. The synthesis method has the advantages of easily available raw materials, mild reaction conditions, small side reaction influence, simplicity and convenience in operation and high yield, improves the yield, is easy to purify, and is suitable for industrial production of omariglitazone.

The invention relates to a particulate composition comprising, or substantially consisting of, urea, an inhibitor, preferably a urease inhibitor and / or a nitrification inhibitor, and an additive, wherein the additive comprises components (i), (ii), and optionally (iii): (i) one or more polyhydric alcohols; preferably one or more carbohydrates, preferably selected from monosaccharides, disaccharides, and oligosaccharides; (ii) a first polymer, preferably an amine-containing polymer; more preferably a polyvinylamine or a polyalkyleneimine; and (ii) optionally, a second polymer, preferably a polar polymer; more preferably a water-soluble polar polymer. The invention further relates to a process for producing the particulate composition, an additive for a particulate composition, and the use of the particulate composition as a fertilizer.

The present invention relates to a process for producing a chiral aromatic amine, said process comprising the steps of: a) providing an aromatic imine, and b) contacting said aromatic imine from step a) with an imine reductase, thereby stereoselectively reducing said aromatic imine to a chiral aromatic amine with said imine reductase; and to novel imine reductases capable of catalytic reactions.

The invention discloses a protein-based adsorbent capable of efficiently adsorbing perfluorinated compounds and application of the protein-based adsorbent. The adsorbent is obtained by coating polyethyleneimine in a phase transition aggregate formed by unfolding protein through a disulfide bond reducing agent. The use method of the adsorbent comprises the step of feeding the adsorbent into a solution containing the perfluorinated compound to realize efficient adsorption of the perfluorinated compound. The adsorbent has the advantages of being low in cost, efficient, easy to operate, environmentally friendly, free of secondary pollution, good in biocompatibility and the like, efficient selective adsorption of perfluorinated compounds can be achieved through the adsorbent, the adsorbent can be repeatedly used, and industrial application and popularization are easy.

The invention relates to the technical field of adsorption materials, and discloses a post-modified imine-COF adsorbent and a preparation method and application thereof, the adsorbent comprises the following structural units: a COF skeleton, which is a two-dimensional or three-dimensional porous skeleton formed by an aromatic aldehyde monomer and an amino monomer through a Schiff base reaction; the imine group is formed in a COF skeleton through a post-modification reaction, and the imine group is-C = NR, r is selected from one or more of a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted heterocyclic group and a hydrogen atom. The adsorbent retains excellent structural characteristics of the COF material, realizes high density and uniform distribution of functional groups, and avoids interference of functional monomers on crystal nucleation and growth, so that the adsorption performance of the adsorbent is improved, and the adsorbent can efficiently capture rare earth when being applied to a rare earth-containing solution.

The invention discloses a low-temperature-resistant working electrolyte for a liquid capacitor and a preparation method of the low-temperature-resistant working electrolyte, and relates to the technical field of electrolytes for capacitors. The low-temperature-resistant working electrolyte is prepared from the following raw materials: ethylene glycol, an auxiliary solvent, a solute, ammonium hypophosphite, a synergist, a stabilizer, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imine, boron nitride nanosheets and 2, 2, 2-trifluoroethyl acrylate. According to the invention, while the auxiliary solvent with a specific proportion is added, the synergist capable of improving the conductivity, the cycle life, the low-temperature ion mobility and the low-temperature power density and the 2, 2, 2-trifluoroethyl acrylate capable of further improving the electrochemical performance stability at the low temperature are also introduced, so that the low-temperature electrochemical performance of the lithium ion battery is improved. And a specific preparation method capable of preventing agglomeration and improving the smoothness of an ion conduction path is combined. Therefore, the electrolyte is more excellent in chemical performance at low temperature and wider in application prospect.

The invention belongs to the technical field of membrane separation, and particularly relates to a method for preparing a high-flux hollow fiber nanofiltration membrane based on interfacial polymerization, the obtained membrane and application. The method comprises the following steps: firstly, carrying out pre-adsorption treatment on a polyethersulfone hollow fiber ultrafiltration base membrane through a polyethyleneimine aqueous solution to form a reactive anchoring layer; then sequentially dipping in an aqueous phase solution containing piperazine, sodium phytate and nanoscale cellulose whiskers and an organic phase solution containing trimesoyl chloride and 5-isocyanate isopeptide acyl chloride for interfacial polymerization; and finally, carrying out heat treatment on the obtained primary composite membrane, and completing a gas-phase cross-linking reaction in a glutaraldehyde steam atmosphere. According to the method, the hollow fiber nanofiltration membrane with high flux, high selectivity, excellent chlorine resistance and pollution resistance is successfully prepared through a multi-stage strengthening process, and the hollow fiber nanofiltration membrane is suitable for the fields of drinking water purification, industrial wastewater reuse, material separation and the like.

The invention belongs to the technical field of semipermeable membrane preparation, and particularly relates to a preparation method of a reverse osmosis membrane. The preparation method comprises the following steps: (1) cleaning the supporting layer for later use; blending diamine, a performance additive and water to obtain a water phase for later use; the preparation method comprises the following steps: blending aromatic acyl chloride, a cosolvent and an organic solvent to obtain an oil phase A for later use, and blending a dynamic crosslinking monomer and the organic solvent to obtain an oil phase B for later use; (2) placing a supporting layer at the bottom of a container, uniformly mixing a water phase and a catalyst, and adding the mixture into the container; and adding the oil phase A into a container to carry out primary condensation reaction, adding the oil phase B to carry out secondary condensation reaction after the reaction is finished, and carrying out post-treatment to obtain the reverse osmosis membrane. According to the invention, a Schiff base-benzene ring bridging structure and a dynamic crosslinking imine bond are introduced through a dynamic crosslinking monomer; and dodecyl ethyoxyl sulphobetaine is matched, so that the chlorine resistance and pollution resistance of the reverse osmosis membrane are improved, and meanwhile, the reverse osmosis membrane has good salt rejection rate and water flux.

The invention discloses application of sulfur quantum dot nanoparticles to improvement of plant waterlogging resistance. The invention provides sulfur quantum dot nanoparticles PEI-SQDs prepared from sulfur, sodium hydroxide, polyethylene glycol and polyethyleneimine. The sulfur quantum dot nanoparticles PEI-SQDs are simple in synthesis method, small in particle size, low in toxicity, low in price, simple to prepare, suitable for large-scale production, good in water solubility and good in biocompatibility; the compound has the capacity of removing active oxygen and ethylene in vitro, and can remove excessive active oxygen and ethylene in plants with waterlogging stress, relieve short-term waterlogging stress suffered by crops and recover growth and development of the crops when being applied to the plants with waterlogging stress; further, long-term waterflooding stress on the crops can be relieved, and the yield of the crops is increased; and the sulfur quantum dot nanoparticles are simple and convenient in use method and obvious in action effect.

The invention discloses an application of NSC348884 in preparation of an antibacterial drug, the bacteria of the NSC348884 are gram-negative bacteria or drug-resistant gram-negative bacteria, and the gram-negative bacteria are acinetobacter baumannii, escherichia coli, pseudomonas aeruginosa or klebsiella pneumoniae; based on an antibacterial drug high-throughput screening technology, it is found from 1280 small molecule compounds that the benzimidazole compound NSC348884 has direct bacteriostasis and sterilization effects on gram-negative bacteria and drug-resistant gram-negative bacteria, and no drug resistance is generated after the benzimidazole compound NSC348884 is continuously applied for 14 days. Further research shows that NSC348884 can interfere with lipid synthesis of gram-negative bacterium cell membranes, inhibit formation of biological membranes and induce lipid metabolism disorder, so that bacteriostatic and bactericidal effects are achieved. In addition, the NSC348884 can also enhance the sensitivity of the drug-resistant bacteria to the imipenem and the polymyxin B.

The invention discloses a synthesis method of oxyalkyl isourea and application of the oxyalkyl isourea as a free radical alkylation reagent. According to the synthesis method, cheap and rich alcohol compounds and carbodiimide are used as raw materials, oxygen alkyl isourea is synthesized in one step under the mild condition of metal catalysis, the synthesis process is simple and convenient, the yield is high, and hectogram-level large-scale preparation can be achieved. The synthesized oxyalkyl isourea can be used as a free radical alkylation reagent to be applied to a coupling reaction of metal catalysis, so that different alkylate products rich in saturated carbon sequence structures are prepared, and the method has a good application prospect.

The invention relates to an application of an imine bond orientation regulation monatomic coordination environment to enhance removal of organic pollutants, and relates to an application of catalytic degradation of organic pollutants. The preparation method comprises the following main steps: preparing two covalent organic framework substrates by using Knoevenagel condensation reaction through simple regulation and control of organic ligand functional group pairing; uniformly dispersing the obtained covalent organic framework material in an organic solvent, stirring and mixing with an organic solvent dissolved with metal ions, and separating and drying to obtain two monatomic catalysts. The regulated monatomic catalyst obtained by the invention shows a better removal effect on organic pollutants, is simple and convenient to operate and high in feasibility, and has good environmental and social benefits.

The application relates to the technical field of packaging films, and discloses an antistatic plastic packaging film and a preparation process.The antistatic plastic packaging film comprises 100 parts by weight of polyethylene, 1-6 parts by weight of phenolic resin polyaniline antistatic agent and 0.2-0.3 parts by weight of an antioxidant.The dodecyl succinic anhydride esterified phenolic resin contains carboxyl groups, can be used as a protonic acid, is doped into polyaniline through an in-situ polymerization reaction, makes imine nitrogen atoms of the polyaniline protonate, forms a charged excited state polaron, and thus the conductivity of the polyaniline is improved, the resistance of the polyethylene is reduced, and the antistatic performance of the packaging film is improved.The dodecyl succinic anhydride esterified phenolic resin and the doped polyaniline have good compatibility with the polyethylene, have a certain reinforcing effect on the polyethylene, and make the film material have higher tensile strength and elongation at break.

The invention belongs to the field of photocatalytic preparation of hydrogen peroxide, and relates to a novel secondary amine linked covalent organic framework material (AR-COF) as well as a preparation method and application thereof. According to the material, tetraaldehyde phenyl porphyrin and 2, 5-diamino-1, 4-benzenediol dihydrochloride are subjected to a Schiff base reaction to synthesize an imine bond connected porphyrinyl covalent organic framework (IM-COF), and then synthesis post-modification (PSM) is performed on the imine bond connected porphyrinyl covalent organic framework (IM-COF) so that the imine bond connected porphyrinyl covalent organic framework (IM-COF) and sodium borohydride can be subjected to a reduction reaction to generate AR-COF. The photocatalytic stability of the material is maintained through modification after synthesis, the catalytic activity is improved, and the original crystal structure is not damaged. A photocatalytic hydrogen peroxide production experiment shows that the catalytic activity of AR-COF under 420 nm monochromatic light is superior to that of IM-COF, the yield under an oxygen condition reaches 7.79 mmol.g <-1 >. H <-1 >, and hydrogen peroxide can be stably produced. The method utilizes solar energy for green synthesis under mild conditions, and provides a safe and efficient method for hydrogen peroxide production.

The invention belongs to the technical field of rubber sealing rings, and particularly discloses a wading rubber sealing ring and a preparation method thereof, the wading rubber sealing ring comprises the following components by weight: 60-70 parts of modified ethylene propylene diene monomer, 35-50 parts of modified white carbon black, 20-30 parts of hydrogenated nitrile rubber, 0-10 parts of fluororubber, 2-5 parts of polyester fiber, 0.5-3 parts of an anti-hydrolysis agent, and 1-3 parts of a hydrophobic agent. 2-4 parts of an antimicrobial agent, 3-5 parts of an anti-aging agent and 1-7 parts of sulfur; the anti-hydrolysis agent is a mixture of tetrakis [beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester and a carbodiimide anti-hydrolysis agent; the hydrophobic agent is a mixture of polydimethylsiloxane and perfluorooctyltriethoxysilane, and the hydrophobic agent is a mixture of polydimethylsiloxane and perfluorooctyltriethoxysilane. The wading rubber sealing rubber ring and the preparation method thereof are suitable for fresh water and warm water scenes, and have wide application prospects in ship sealing and sewage treatment equipment in seawater and industrial wastewater scenes.

The invention belongs to the technical field of high polymer materials, and particularly discloses a lignin-based charring agent containing silicon and nitrogen flame-retardant elements and an imine structure for flame-retardant polylactic acid and a preparation method of the lignin-based charring agent. The flame-retardant polylactic acid is prepared from the following components in parts by weight: 90 to 97 parts of polylactic acid, 1 to 3.33 parts of lignin-based charring agent and 2 to 6.67 parts of ammonium polyphosphate. The bio-based charring agent disclosed by the invention contains silicon and nitrogen flame-retardant elements and an imine structure, has remarkable charring and flame-retardant effects, is high in charring capacity, and can endow the PLA with relatively good flame-retardant property by compounding with ammonium polyphosphate and adding 1% of the lignin-based charring agent; the lignin and vanillin which are used as main raw materials for synthesizing the charring agent are bio-based sources and are easy to obtain, the production process is simple, industrial production is easy, the preparation process is non-toxic and environment-friendly, the dependence of charring agent synthesis on petroleum-based raw materials can be effectively relieved, and the sustainable development trend of materials is met.

The application relates to a modified PA56 fabric with long-acting flame-retardant effect and a preparation method thereof, wherein hyperbranched polyethylene imine and ammonium polyphosphate are grafted to obtain hyperbranched modified ammonium polyphosphate, the PA56 fabric is dipped in a hyperbranched modified ammonium polyphosphate solution and dried and solidified, dipped in a melamine flame-retardant finishing agent, then dipped in an acetic acid buffer solution, and dried to obtain the modified PA56 fabric with long-acting flame-retardant effect. Different from the prior art, the hyperbranched modified ammonium polyphosphate is loaded on the PA56 fabric to form a crosslinked network structure; the polyethylene imine is loaded on the PA56 fabric; the ammonium polyphosphate is connected with the polyethylene imine through grafting modification; the melamine is connected with the ammonium polyphosphate through weak bonds such as electrostatic interaction, hydrogen bond and P-N bond, and is wrapped in the outer layer of the fabric, so that the durable flame-retardant effect of the modified PA56 fabric is realized, and the strength of the modified PA fabric is improved.

The invention discloses a modified microfiltration membrane for enriching biological particles and a preparation method and application thereof, and belongs to the technical field of biological separation.The preparation method of the modified microfiltration membrane comprises the following steps that a mixed cellulose ester microfiltration membrane is provided and subjected to alkali liquor activating treatment; placing the activated membrane in a weakly alkaline buffer solution for balancing; the preparation method comprises the following steps: in a weakly alkaline buffer solution, firstly contacting the surface of the membrane with a tannic acid solution to carry out a first reaction, and then directly adding a polyethyleneimine solution to carry out a second reaction under the condition of not replacing a system, so as to form a phenol-amine cross-linked network on the surface of the membrane in situ; sodium cyanoborohydride is continuously added for reduction stabilization treatment, and the modified microporous filter membrane is obtained. The modified microporous filter membrane prepared by modifying the microporous filter membrane with tannic acid and polyethyleneimine can realize one-step synchronous enrichment of all negatively charged targets, and the problems of target loss, efficiency loss and the like caused by a multi-step process are avoided from the source.

The present disclosure discloses a medical hydrogel, formed by in-situ crosslinking an aldehyde-terminated multi-arm star polyethylene glycol and a polyamino compound, wherein the aldehyde group and the multi-arm star polyethylene glycol are linked by a chemical bond such as an ether bond, an amide bond, an ester bond, a urethane bond, an imine bond, or a urea bond, and the molar ratio of the amino in the polyamino compound to the aldehyde group in the aldehyde-terminated multi-arm star polyethylene glycol is 0.4-4.4:1. The polyamino compound is polylysine or a mixture of polylysine and polyethylenimine in a molar ratio of 2-30:3. The hydrogel of the present disclosure gels rapidly, has a long-term stability in an aqueous solution, and still has good swelling property and stability after a plurality of radiations, and thus can be used as a medical radiotherapy protection spacer for radiation protection.

The invention relates to a method for preparing (S)-chiral amine through asymmetric catalysis of imine reductase, and belongs to the technical field of biological pharmacy. Comprising the following steps that imine reductase catalyzes imine to be subjected to a reductive hydrogenation reaction under the conditions of coenzyme and a coenzyme regeneration system, and the (S)-chiral amine compound is generated. According to the method, imine reductase is utilized to catalyze imine asymmetric reduction to prepare the innovative drug (S)-chiral amine compound, and compared with a traditional chemical synthesis method, the method has the advantages of being high in reaction efficiency, good in stereoselectivity, mild in reaction condition, environmentally friendly and the like, and is a method meeting the green production requirement.

The invention discloses a reversible cross-linked paper coating and a repulping switching process, and belongs to the technical field of paper coatings. The coating is composed of an acrylate emulsion, a polyhydroxyalkanoate dispersion and a dynamic cross-linking system, wherein the system is one of carbonyl-hydrazine, imine, Diels-Alder, ester exchange, borate or polyvalent metal-carboxylate. The coating is coated with 6-15 g / m, the use state is that Cobb60 is smaller than or equal to 18 g / m, Kit is larger than or equal to 10, WVTR is smaller than or equal to 80 g / (m.d) at the temperature of 38 DEG C and the RH of 90%, OTR is smaller than or equal to 200 cm / (m.d) at the RH of 23 DEG C / 80%, the initial sealing temperature is smaller than or equal to 180 DEG C, and the sealing strength is larger than or equal to 6.0 N / 15 mm. In the re-pulping stage, net releasing is triggered through alkali, acid (containing CO2 injection), a chelating agent or ultrasonic assistance, and according to CEPI V3 / PTS-RH 021: 2012, the fiber recovery rate is measured to be larger than or equal to 98%, the coarse slag rate is measured to be smaller than or equal to 1.0%, and the adhesion matter is measured to be smaller than or equal to grade 1. The formula does not contain PFAS, and high bio-based carbon content can be realized.

The invention relates to a high-performance positively charged composite membrane and a preparation method thereof, in particular to a nanofiltration membrane containing a sulfonated imino covalent organic framework (TpPa-SO3H) interlayer. The nanofiltration membrane adopts a three-layer structure design, and comprises a base membrane layer, a TpPa-SO3H middle interlayer and a positively charged separation surface layer. Wherein the TpPa-SO3H interlayer is formed by in-situ growth of polyphenol and sulfated amine under the action of an oxidizing agent, and the separation surface layer is assembled and constructed through electrostatic attraction and hydrogen-bond interaction between positively charged polyelectrolyte and sulfonic acid groups. The TpPa-SO3H interlayer is introduced to effectively regulate and control the pore size distribution and hydrophilicity of the surface of the substrate, the formed negative electricity interlayer can promote the assembly of a polyelectrolyte positive electricity layer, and the interception performance and the operation stability of the composite membrane on heavy metal cations are remarkably improved. Compared with a traditional nanofiltration membrane, the composite membrane prepared through the method keeps high water flux (larger than or equal to 40 L.m <-2 >. H <-1 >. Bar <-1 >), meanwhile, the rejection rate of heavy metal cations such as Cr < 3 + >, Mn < 2 + > and Co < 2 + > is larger than or equal to 95%, and the composite membrane has excellent long-term operation stability. The preparation method is simple in process and low in cost, and has a wide application prospect in the field of heavy metal wastewater treatment.

The invention belongs to the technical field of temporary plugging agents, and relates to a medium-temperature drilling fluid nano temporary plugging agent and a preparation method thereof. The temporary plugging agent is prepared from the following raw materials in parts by mass: 10 to 15 parts of small-particle-size coated silicon dioxide, 15 to 20 parts of medium-particle-size coated silicon dioxide, 30 to 50 parts of large-particle-size coated silicon dioxide, 15 to 20 parts of fiber, 5 to 8 parts of polyether diglycidyl ether, 5 to 8 parts of hyperbranched polyethyleneimine, 1 to 1.5 parts of water-soluble cellulose and 0.5 to 1 part of cationic quaternary ammonium salt. The coated silicon dioxide takes chitosan and glutaraldehyde as wall raw materials and silicon dioxide as a core material, and the particle size of the small-particle-size core material is 0.3-1 mu m; the particle size of the medium-particle-size particle core material is 150-250 microns; the particle size of the large-particle-size particle core material is 250-350 microns, the coated silicon dioxide particles are bonded together through a microscopic interpenetrating network formed by the reaction of hyperbranched polyethyleneimine and polyether diglycidyl ether, and the particles are matched with fibers to improve the bearing strength.