1278 results about "Vinyl alcohol" patented technology

The invention discloses a corrosion-resistant protective sleeve for an aluminum alloy cable and a preparation method of the corrosion-resistant protective sleeve, and belongs to the field of cable protective sleeves. The corrosion-resistant protective sleeve for the aluminum alloy cable is prepared from the following raw materials in parts by mass: 40 to 50 parts of ethylene propylene diene monomer, 15 to 25 parts of fluorinated silicone rubber, 5 to 10 parts of modified thiolated ethylene-vinyl alcohol copolymer, 8 to 15 parts of metal fluoride nanocrystal, 4 to 8 parts of vulcanizing agent, 3 to 8 parts of plasticizer and 3 to 5 parts of flame retardant. The two rubber matrixes are compounded to form a physical barrier layer to prevent corrosion media and water molecules from permeating, material pores can be filled with the metal fluoride nanocrystals, diffusion channels of the corrosion media are reduced, and hydrophobicity and corrosion resistance are improved through cooperation of the metal fluoride nanocrystals and the fluorinated silicone rubber. The modified thiolated ethylene-vinyl alcohol copolymer can improve the compatibility between rubber matrixes and form coordination with metal ions of the metal fluoride nanocrystals, so that the diffusion path of a corrosive medium is prolonged, and the corrosion of the corrosive medium is synergistically blocked.

The invention relates to the technical field of pharmaceutical preparations, and provides a minoxidil film coating agent as well as a preparation method and application thereof. The minoxidil film coating agent provided by the invention comprises 40-60% of propylene glycol, 3-7% of polyvinyl alcohol, 20-30% of ethanol, 1-7% of minoxidil and the balance of water. According to the invention, propylene glycol is taken as a solvent, a plasticizer and a transdermal absorption enhancer, polyvinyl alcohol is taken as a film-forming material, and ethanol is taken as a volatile agent, after administration, ethanol is volatilized to promote film formation of polyvinyl alcohol, and propylene glycol enhances the plasticity of the formed film, so that the effect of reducing liquid medicine loss is achieved, the local medicine concentration is increased, and the bioavailability is improved. The minoxidil liniment disclosed by the invention has excellent skin permeability, can effectively convey a medicine to a required part, and can ensure that the medicine is released at a fixed position of the skin and is accurately administered in a medicine release process, so that the stimulation of liquid medicine flow to other parts is reduced, and a good treatment effect is achieved.

The application discloses a kind of imitated plant leaf hydrogel composite material and preparation method thereof, belong to bionic composite material field.The application first by colorant compounding preparation printing paste, and fabric is printed, obtain the green fabric that can realize to plant leaf " green peak " and " red edge " spectral characteristic simulation, and with green fabric simulation leaf structure in fence organization and skeleton;Then with biomaterial polyvinyl alcohol (PVA) as base material, join with strong hygroscopic monomer and crosslinking agent, initiator blend preparation hydrogel prepolymer solution;Finally, hydrogel prepolymer solution is poured into the mold containing green fabric and copolymerization, it directly forms hydrogel in fabric surface and pore interior, obtains imitated plant leaf hydrogel composite material.The material gets rid of the dependence on hygroscopic salt, has water absorption and simulation effect stable, durability is good and the like advantages.

The invention relates to the technical field of water pollutant removal, in particular to a UiO-66 / sodium carboxymethyl cellulose / polyvinyl alcohol / melamine sponge composite material and a preparation method and application thereof.The preparation method comprises the steps that zirconium chloride and terephthalic acid are dissolved in an organic solvent to obtain a mixed solution, the mixed solution is transferred into a reaction kettle, and through solvothermal reaction, the UiO-66 / sodium carboxymethyl cellulose / polyvinyl alcohol / melamine sponge composite material is obtained; the preparation method comprises the following steps: preparing UiO-66 powder; putting UiO-66 powder into the sodium carboxymethyl cellulose solution, and uniformly stirring the UiO-66 powder and the sodium carboxymethyl cellulose solution to obtain a UiO-66 / CMC mixed solution; placing the UiO-66 / CMC mixed solution in a polyvinyl alcohol solution, and uniformly stirring the UiO-66 / CMC / PVA mixed solution to obtain a UiO-66 / CMC / PVA mixed solution; the preparation method comprises the following steps: dipping a melamine sponge in a UiO-66 / CMC / PVA mixed solution to obtain an adsorption saturated melamine sponge; the UiO-66 / CMC / PVA / coated MS composite material is obtained by repeatedly freezing and thawing the adsorption saturated melamine sponge for multiple times and then freeze-drying, the composite material can be used for rapidly, efficiently and selectively removing phosphate or fluorine ions and the like in water and is convenient to separate and recycle, and a new thought is provided for development of efficient water treatment adsorbent materials.

Provided in the present invention are a polyvinyl alcohol powder and hydrogel, and a preparation method therefor and the use thereof. The method mainly comprises: preparing a polyvinyl alcohol powder from polyvinyl alcohol, then mixing same with water and swirling same to make the powder swell into discrete microgel particles, and applying pressure to make polyvinyl alcohol molecular chains at the interface of the microgel diffuse, entangle and link with each other and crystallize and fuse, so as to prepare a polyvinyl alcohol hydrogel. With regard to the polyvinyl alcohol powder, the preparation method therefor comprises direct pulverization, or physical crosslinking prior to pulverization, or casting into a film prior to pulverization, etc.; and preferably, the powder is prepared by first performing casting into a film and then pulverizing same, which can make the powder more uniform in terms of crystallinity and more stable in terms of performance. With regard to the swelling process of the polyvinyl alcohol powder, it is necessary to strictly control the ratio of the powder to water, the temperature and the time to ensure that before swelling is complete, transferral into a mold is conducted and pressure is applied to form a hydrogel. Products meeting different performance requirements, including prostheses for the soft tissues of various locomotor systems, medical and esthetic filling materials, etc., are prepared by adjusting process parameters; and the polyvinyl alcohol powder can also be used for preparing PVA plastics having a three-dimensional structure, and thus has broad application prospects.

This invention discloses a one-piece molded all-plastic flexible hose sheet and its composite hose, belonging to the field of polymer material technology. The one-piece molded all-plastic flexible hose sheet of this invention has a three-layer structure: an outer PE film, an intermediate layer, and an inner PE film. The intermediate layer is selected from one of the following: an intermediate polymer layer, a three-layer composite layer formed by an intermediate polymer layer, a polyethylene layer, and an intermediate polymer layer, or a three-layer composite layer formed by an intermediate polymer layer, an ethylene-vinyl alcohol copolymer layer, and an intermediate polymer layer; the intermediate layer may have a double-sided coated or uncoated adhesive layer; the intermediate polymer layer is polymerized from 2,6-dihydroxyisophthalic acid, diaminoalkane, and 4,4'-tetraphenylsilane. The all-plastic flexible hose sheet provided by this invention is formed in one piece using a five-layer co-extrusion machine, possessing excellent gas barrier properties, water vapor barrier properties, high mechanical strength, and good interlayer peel strength.

The invention discloses a high-barrier polyethylene film and a preparation method thereof, and relates to the technical field of high polymer materials. The invention discloses a high-barrier polyethylene film. The high-density polyethylene composite material is prepared from the following raw materials in parts by weight: 25 to 40 parts of high-density polyethylene, 15 to 30 parts of linear low-density polyethylene, 8 to 16 parts of ethylene-vinyl alcohol copolymer, 3 to 8 parts of nano montmorillonite, 5 to 10 parts of modified layered double hydroxide, 2 to 6 parts of nano silicon dioxide aerogel, 0.2 to 0.6 part of antioxidant 1076, 0.1 to 0.4 part of light stabilizer UV-770, 3 to 7 parts of tributyl citrate and 1 to 3 parts of octadecanamide. 1-3 parts of polyethylene wax, 0.6-1.2 parts of a silane coupling agent KH560 and 7-12 parts of a functional additive. According to the high-barrier polyethylene film disclosed by the invention, by using the modified layered double hydroxide and the functional additive, the barrier property and the antibacterial property are enhanced, the mechanical property is improved, the comprehensive performance is excellent, and the application prospect is good.

The invention relates to the technical field of fire extinguishing microcapsules, in particular to a high-airtightness perfluorohexanone fire extinguishing microcapsule and a preparation method and application thereof.The perfluorohexanone fire extinguishing microcapsule comprises a composite shell layer and a fire extinguishing core, and the composite shell layer is made of ethylene-vinyl alcohol copolymer resin and silicon dioxide nanoparticles; the fire extinguishing core is a perfluorohexanone fire extinguishing agent and is applied to preparation of indoor fire extinguishing pastes, fireproof coatings and polyurethane adhesive materials. According to the perfluorohexanone fire extinguishing microcapsule disclosed by the invention, the diffusion of low-polarity perfluorohexanone is effectively prevented by utilizing the strong hydrogen-bond interaction between hydroxyl groups in the ethylene-vinyl alcohol copolymer resin, and especially under the condition of relatively high temperature, the perfluorohexanone fire extinguishing microcapsule has a good fire extinguishing effect. The problem that an existing perfluorohexanone fire extinguishing microcapsule is poor in long-term air tightness under the condition of high encapsulation efficiency is effectively solved, and meanwhile harmful substances such as formaldehyde cannot be generated.

The invention belongs to the field of functional textile materials, and provides a one-way moisture-conducting breathable fabric based on a vinyl elastomer and a preparation method of the one-way moisture-conducting breathable fabric based on the vinyl elastomer. The hydrophilic coating contains a vinyl elastomer matrix, polyvinyl alcohol, a zwitterionic polymer and a cross-linking agent, the hydrophobic coating contains a vinyl elastomer matrix, vinyl-terminated polydimethylsiloxane, polyhedral oligomeric silsesquioxane and other components, the coatings are only attached to the surfaces of yarn fibers and do not block pores, and a wettability gradient structure is formed; the excellent performance that the static contact angle gradient in the thickness direction is larger than or equal to 50 degrees, the capillary water absorption height from the inner side to the outer side is larger than or equal to 3.0 cm / 10 min, the capillary water absorption height from the outer side to the inner side is smaller than or equal to 1.0 cm / 10 min, the moisture permeation amount is larger than or equal to 5000 g.m.24 h, and the air permeability after curing is 65% or above of a fabric base material is achieved, the technical problem that an existing fabric is insufficient in moisture conductivity and air permeability is solved, and wide application value is achieved.

The invention discloses a polypropylene composite material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The polypropylene composite material is prepared from the following components in parts by weight: 44 to 60 parts of polypropylene resin, 5 to 15 parts of ethylene-vinyl alcohol copolymer, 10 to 25 parts of modified talcum powder and 15 to 25 parts of toughening agent. The polypropylene resin, the ethylene-vinyl alcohol copolymer, the modified talcum powder, the flexibilizer and the antioxidant are compounded, the compatibility of all the components is good, the compounded material has good bonding performance with other plastic materials (such as PMMA), meanwhile, the tensile strength and impact strength of the polypropylene composite material can be effectively improved, and the service life of the polypropylene composite material is prolonged. The requirements of automobile decorative parts on the adhesive property, the rigidity and the toughness can be met.

The invention discloses a low-shrinkage acrylate gel material and a preparation method thereof. The gel material is prepared by mixing a solution A and a solution B according to an equal proportion, the liquid A comprises acrylate, a cross-linking agent, an accelerant and a retarder; the acrylate is a calcium acrylate solution, a magnesium acrylate solution or a mixed solution of calcium acrylate and magnesium acrylate; the concentration of the acrylate in the solution A is 15wt.%-35wt.%; the liquid A is also added with a modified material, and the modified material is selected from at least one of hydroxyethyl ester, chloroprene rubber, polyurethane, polyvinyl alcohol and epoxy resin; the addition amount of the modified material is 1%-5% of the total mass of the solution A; the solution B comprises an initiator and distilled water; the initiator is selected from at least one of ammonium persulfate, hydrogen peroxide and azodiisobutyronitrile; the use amount of distilled water in the solution B is determined according to initiator concentration; by optimizing an acrylate compound system, introducing an anti-shrinkage functional component and accurately controlling a preparation process, the comprehensive improvement of material performance and engineering applicability is finally realized.

The invention relates to a preparation method of quartz sand, and belongs to the technical field of quartz. The preparation method comprises the following steps: S1, adding a polyvinyl butyral solution into silica sol, and uniformly stirring to obtain silica sol dispersion liquid; the polyvinyl butyral solution comprises polyvinyl butyral (PVB) and tert-butyl alcohol; s2, performing spray drying on the silica sol dispersion liquid to obtain quartz microspheres; and S3, carrying out oxidation carbon removal treatment and vacuum dehydroxylation treatment on the quartz microspheres to obtain the quartz sand. Drying cracking and micro-hollow structure defects of the quartz sand can be effectively eliminated, it is ensured that the product is compact and free of pores, and the structural integrity and the use reliability are greatly improved; the density performance bottleneck of quartz sand is successfully broken through, and the bulk density after sintering is remarkably improved; the particle size distribution of the quartz sand can be accurately controlled, and the product particle size uniformity is ensured.

The invention discloses a metal powder metallurgy forming process, and belongs to the technical field of metal powder metallurgy. The process comprises the following steps: preparing a metal mixture containing tungsten, copper, nickel, iron and an interface toughening agent according to a specific proportion, adding a polyvinyl alcohol aqueous solution, and uniformly stirring; carrying out compression molding on the mixture to obtain a green body; performing high-temperature sintering steps such as pre-sintering, sintering and cooling to obtain a sintered blank; and finally shaping to obtain a finished product. Compared with the prior art, the fracture toughness and elongation performance of the material are remarkably improved, innovative breakthrough is brought to a metal powder metallurgy forming process, and the method can be widely applied to the fields of aerospace, automobile manufacturing and the like to meet the requirements for high-performance metal parts.

The invention relates to a high-strength self-cleaning infrared radiation heat dissipation water-based coating as well as a preparation method and application thereof. The coating comprises the following components in parts by weight: 40-55 parts of water, 5-10 parts of a water-based binder, not more than 20 parts of a high-emissivity filler and not more than 5 parts of a fluorocarbon surfactant, the water-based binder is selected from at least one of styrene-acrylic emulsion, water-based polyurethane, polyvinyl alcohol, water-based acrylic resin, water-based epoxy resin and water-based alkyd resin, and the fluorocarbon surfactant is selected from at least one of water-based acrylic emulsion, water-based polyurethane, polyvinyl alcohol, water-based acrylic resin, water-based epoxy resin and water-based alkyd resin. The high-emissivity filler is selected from at least one of BaSO4, ZnO, Al2O3, SiC, BN (boron nitride) and SiO2, and the fluorocarbon surfactant is selected from at least one of FS-65, FS-34, ST-110, FC-4432 and FS-3100. According to the invention, ZnO, BaSO4 and the like are introduced as composite fillers, so that the coating is endowed with high strength, self-cleaning property and full-wave-band high emissivity, various properties such as wear resistance, adhesion, acid and alkali resistance, organic solvent corrosion resistance, aging resistance, high and low temperature resistance and the like of the coating are improved, and the coating can meet the requirements of various different heat dissipation scenes when being applied to electronic components.

The invention discloses a production method of a high-barrier BOPA film. The BOPA film comprises a surface layer, a middle layer and an inner layer, and the surface layer is composed of PA6, MXD12 and polyhedral oligomeric silsesquioxane; the middle layer is prepared from PA6, aliphatic polyketone and graphene oxide nylon master batch; the inner layer is composed of PA6, organically modified vermiculite, POE-g-MAH, an ethylene-vinyl alcohol copolymer and an antioxidant. The BOPA film prepared by the invention has the advantage of high barrier and has better mechanical properties.

The invention discloses a carbon quantum dot-polyvinyl alcohol composite film and a preparation method thereof, and belongs to the technical field of food packaging fresh-keeping materials. The composite film is prepared by taking apocynum venetum carbon quantum dots and polyvinyl alcohol as raw materials under the action of a plasticizer, wherein the apocynum venetum carbon quantum dots are prepared from apocynum venetum fiber powder, dithiosalicylic acid and urea through a hydrothermal method. The composite film provided by the invention has excellent ultraviolet shielding, pH-responsive fluorescence discoloration, antibacterial and antioxidant properties, and can realize visual monitoring of the freshness of high-protein food. The preparation method disclosed by the invention is simple in process, environment-friendly, suitable for the field of food active packaging and wide in application prospect.

The invention discloses a floor heating structure with a phase change material layer and a preparation method of the floor heating structure, and belongs to a floor heating structure, the floor heating structure comprises a base material layer, the phase change material layer, an auxiliary heat conduction layer and a floor surface layer from bottom to top in sequence; a metal heat-conducting net is embedded into the lower part of the base material layer; the phase change material layer comprises the following components in percentage by weight: 53%-58% of methyl laurate, 30%-35% of n-decanol, 5%-8% of nano aluminum oxide, 4%-6% of polyvinyl alcohol and 0.5%-1.5% of carboxymethyl cellulose. Solid-liquid phase change is carried out through the phase change material layer, redundant heat is absorbed, latent heat is released when a heat source is shut down, and therefore frequent starting and stopping of the heat source are reduced, and energy consumption is reduced. According to the multi-layer heat conduction design, through collaborative optimization of the metal heat conduction net and the auxiliary heat conduction layer, the heat efficiency of the floor heating structure is further improved, the heat response time is shortened, the latent heat characteristic of the phase change material is utilized, the heat buffering effect can be achieved in the floor, the heating temperature fluctuation range is reduced, and the heating comfort is improved.

The invention discloses a high-strength polyethylene film and a preparation method thereof, and relates to the technical field of high polymer materials. The invention discloses a high-strength polyethylene film. The high-density polyethylene composite material comprises the following raw materials in parts by weight: 40-60 parts of high-density polyethylene, 13-25 parts of low-density polyethylene, 5-10 parts of an ethylene-vinyl alcohol copolymer, 10-15 parts of modified nano calcium carbonate, 3-5 parts of modified lignin fibers, 0.5-1 part of an antioxidant 1010, 0.3-0.7 part of a light stabilizer 770, 1-2 parts of zinc stearate and 2-3 parts of maleic anhydride grafted polyethylene. The coating comprises, by weight, 20-30 parts of polyethylene glycol terephthalate, 3-5 parts of poly (butylene adipate-co-butylene terephthalate), 2-4 parts of talcum powder, 1-3 parts of polymethyl methacrylate and 30-45 parts of deionized water. The high-strength polyethylene film is scientific in raw material ratio, and contains various modified components to enhance the performance; the modified nano calcium carbonate and lignin fiber technology is advanced, and compatibility and stability are improved; the preparation method is reasonable, and the film has the characteristics of high strength, good toughness, oxidation resistance, light resistance and the like and is wide in application through two-way stretching and other procedures.

The invention discloses manganese-based Prussian blue-polyacrylic acid / polyvinyl alcohol hydrogel for preventing and treating allergic rhinitis. Monodisperse manganese-based Prussian blue nanoparticles synthesized by taking polyacrylic acid as a template are stably immobilized in a polyacrylic acid / polyvinyl alcohol hydrogel matrix. The obtained composite hydrogel membrane has the following prominent advantages: the composite hydrogel membrane has excellent hydrogel characteristics, including controllable membrane thickness, good tissue adhesion and air permeability; reliable biocompatibility and safety are shown; allergen permeation is effectively blocked through a physical barrier effect; prussian blue is continuously released in the slow-release degradation process, active oxygen free radicals are remarkably removed, and the powerful anti-inflammatory effect is achieved. Due to the synergistic effect of double mechanisms of protection and treatment, the material has important clinical application value and development potential in the fields of prevention and treatment of allergic rhinitis.

The application relates to the packaging technical field and discloses a high-barrier antibacterial food packaging film and a preparation method.The raw materials of the packaging film of the application include 100 parts by weight of polyvinyl alcohol, 2-8 parts by weight of modified polyvinyl alcohol, 5-30 parts by weight of carboxymethyl chitosan and 5-20 parts by weight of sodium-based montmorillonite;the modified polyvinyl alcohol contains quaternary ammonium salt as an antibacterial group, cooperatively plays an antibacterial role with the carboxymethyl chitosan and significantly improves the antibacterial performance of the packaging film.The modified polyvinyl alcohol introduces a quaternary ammonium salt cation structure with smaller steric hindrance at the side chain end, facilitates ion exchange of the montmorillonite, modifies the polyvinyl alcohol molecular chain on the surface of the montmorillonite, improves the compatibility and dispersibility of the montmorillonite in the polyvinyl alcohol packaging film and is beneficial to improving the mechanical strength and gas barrier performance of the packaging film.

The invention discloses a gel microneedle loaded with silver nanoparticles and a preparation method and application thereof.The extract nano-silver (AB-AgNPs) is prepared through a green synthesis strategy, a drug-loaded microneedle system is constructed based on carboxymethyl chitosan-vanillic aldehyde-polyvinyl alcohol (CMCS-Va-PVA) composite gel, the AB-AgNPs prepared through the technology are uniform in particle size and stable in dispersion, and the drug-loaded microneedle has the advantages that the drug-loaded microneedle is good in drug-loaded performance and good in drug-loaded performance; the crystal has a typical face-centered cubic crystal structure and metal state Ag0 characteristics; the gel microneedle has good mechanical strength and forming effect, the AB-AgNPs and the gel matrix are stably combined through hydrogen bonds, the chemical properties are kept unchanged, and the system has broad-spectrum efficient bacteriostatic activity and biocompatibility; an in-vitro experiment proves that the green synthesized gel microneedle loaded with the silver nanoparticles has a remarkable capability of promoting the healing of L929 cell tissues; a rat wound experiment proves that the gel microneedle can regulate and control an inflammatory factor network and promote cell migration and tissue regeneration, healing of common and infected wounds is remarkably accelerated, and the wound residue ratio in 9 days is as low as 2.7% and 10.9% respectively.

The invention relates to the technical field of high polymer materials, and particularly discloses a water-soluble polyvinyl butyral emulsion and a preparation method thereof.The preparation method comprises the following preparation steps that dissolving is conducted, PVB and ethyl alcohol are dissolved, the dissolving temperature ranges from 50 DEG C to 60 DEG C, the dissolving time ranges from 1 h to 3 h, and a dissolving solution is obtained; base catalytic emulsification: sequentially adding a composite plasticizer and a composite emulsifier into the obtained dissolved solution, stirring and mixing, then slowly dropwise adding alkali liquor into a reaction system, and reacting for 0.2-0.8 hour to obtain primary emulsion; shearing and emulsifying: adding the acrylate core-shell emulsion into the obtained primary emulsion, and then carrying out high-speed shearing and emulsifying to obtain a composite emulsion; and adding a compound thickening agent into the obtained composite emulsion, and stirring for at least 20 minutes to obtain the network-shaped water-soluble polyvinyl butyral emulsion.

A resin composition that contains: (A) a bio-polyethylene resin; (B) an ethylene-vinyl alcohol copolymer having an ethylene content of 20 to 60 mol %; and (C) at least one component selected from the group consisting of an ethylene-vinyl acetate copolymer, an acid-modified ethylene-α-olefin copolymer, an ethylene-unsaturated monocarboxylic acid copolymer, an ionomer of the ethylene-unsaturated monocarboxylic acid copolymer, an ethylene-vinyl alcohol copolymer having an ethylene content of 70 to 90 mol %, and a hydrotalcite compound. The resin composition employs a bio-polyethylene resin and yet can suppress gumming and provide a formed product having an excellent appearance.

The present invention provides: a vapor-deposited multilayer film which has high oxygen barrier properties and high water vapor barrier properties, and has sufficient oxygen barrier properties even after a bending treatment; and the like. Provided is a vapor-deposited multilayer film comprising: a multilayer film in which a layer (A), as the outermost layer, a layer (B), and a layer (C) are stacked in this order; and a vapor-deposited inorganic layer (I) stacked on the exposed surface side of the layer (A). The vapor-deposited inorganic layer (I) is a vapor-deposited metal layer that is mainly composed of aluminum, or a vapor-deposited inorganic oxide layer that is mainly composed of alumina or silica. The layer (A) contains, as a main component, an ethylene-vinyl alcohol copolymer (a) that has an ethylene unit content of 36-60 mol%; the layer (B) contains, as a main component, an ethylene-vinyl alcohol copolymer (b) that has an ethylene unit content of 20-35 mol%; and the layer (C) contains a polyethylene or a polypropylene as a main component. The average thickness of the multilayer film is 300 µm or less.

The invention discloses a graphene / aluminum alloy composite material with high conductivity and a preparation method thereof, and belongs to the technical field of metal-based composite materials. And the electric conductivity is not lower than 70% IACS. The preparation method comprises the following steps: carrying out surface copper plating pretreatment on aluminum alloy powder; performing ultrasonic dispersion on graphene by using a polyvinyl alcohol solution to obtain a stable dispersion liquid; mixing, stirring, drying and filtering the copper-plated powder and the graphene dispersion liquid to obtain graphene-coated composite powder; and finally, carrying out rapid densification sintering by adopting a spark plasma sintering technology. The core innovation point of the preparation method is that the problem of dispersion and interface combination of graphene in an aluminum matrix is solved synergistically through combination of a copper plating transition layer and PVA auxiliary dispersion-adsorption coating, then interface reaction is avoided through SPS rapid sintering, finally, the composite material with excellent conductivity is obtained, and the technical index reaches the domestic leading level.

The invention discloses an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer and a preparation method thereof, and belongs to the field of polymers. Comprising the following steps: putting a mixture containing an initiator, a chain transfer agent, a solvent and vinyl acetate into a closed container, introducing ethylene gas, and carrying out pressurized polymerization to obtain the ethylene-vinyl acetate copolymer, the initiator is selected from at least one of lauroyl peroxide, benzoyl peroxide, azodiisobutyronitrile and azobisisoheptonitrile; the chain transfer agent is selected from the group consisting of 2-dimethylaminoethyl acetate and / or 2-dimethylaminoethyl propionate. The preparation method of the low-branching-degree EVA has the characteristics of mild conditions, strong controllability, simplicity in operation and large-scale application prospect. The invention also provides an ethylene-vinyl alcohol copolymer prepared from the prepared EVA through alcoholysis reaction, and the ethylene-vinyl alcohol copolymer has the characteristics of high molecular weight, narrow distribution, good appearance and the like, and meets the application requirements of commercial EVOH.

The invention discloses a method for preparing a polyvinyl alcohol flame-retardant film by using walnut green seedcase carbon dots and application of the polyvinyl alcohol flame-retardant film, and belongs to the technical field of composite materials. The preparation method of the flame-retardant film comprises the following steps: mixing a walnut green seedcase carbon dot solution with polyvinyl alcohol, carrying out oil bath heating treatment, cooling to room temperature, carrying out film forming on the obtained walnut green seedcase carbon dot-polyvinyl alcohol mixed solution in a casting manner, and finally, carrying out drying treatment to obtain the target flame-retardant film. According to the method, the walnut green seedcase is used as a raw material to prepare the carbon dots, hydrolytic tannin and quercetin components contained in the walnut green seedcase are fully utilized, resource recycling of waste is achieved, and the production cost of the flame-retardant film is remarkably reduced. The prepared flame-retardant film has the characteristics of portability and certain mechanical strength, is suitable for various scenes with requirements on light flame-retardant materials, has an excellent flame-retardant effect, can effectively delay or even block flame diffusion, and greatly improves the use safety of the materials.

The invention discloses a high-humidity-resistant high-barrier coating film and a preparation method thereof, and belongs to the technical field of polymer composite materials. The coating film comprises a base film and a coating layer, wherein the coating layer is prepared from a coating liquid containing an ethylene-vinyl alcohol copolymer, acetoacetyl modified polyvinyl alcohol, amino silane modified boron nitride nanosheets, hydroxyl modified potassium titanate whiskers, a water-based polyfunctional aziridine cross-linking agent and an epoxy silane coupling agent. A multi-phase synergistic system of a polymer matrix-nano material-cross-linked network is constructed, a three-dimensional barrier network is constructed by utilizing the synergistic effect of two-dimensional nanosheets and one-dimensional whiskers, and meanwhile, the number of hydrophilic groups is reduced through a specific cross-linking reaction, so that the barrier stability of the material in a high-humidity environment is remarkably improved. The film has excellent oxygen and water vapor barrier property, good mechanical strength, thermal stability and aging resistance, and can be widely applied to the field of high-end packaging of food, medicines and precise instruments.

The invention provides a composite anion exchange membrane and a preparation method thereof. The composite anion exchange membrane comprises a polyaryl piperidine polymer and a polyvinyl alcohol polymer, the structural general formula of the composite anion exchange membrane is shown in the specification, x represents the degree of polymerization, and the value range of x is 10-1000; and Ar is selected from any one of arylene groups of C12 to C40. Due to the introduction of the polyvinyl alcohol polymer, the mechanical strength of the composite anion-exchange membrane is remarkably enhanced, the integrity and functionality of the composite anion-exchange membrane can be kept under the action of high-pressure or high-strength mechanical stress, and the common physical damage problem of a traditional anion-exchange membrane in the operation process is avoided. Therefore, the composite anion exchange membrane not only has higher ion exchange capacity, but also has additional mechanical property improvement through the synergistic effect of the polyaryl piperidine polymer and the polyvinyl alcohol polymer.