391results about "Chitin coatings" patented technology

The invention relates to the technical field of high-barrier composite packaging films, and discloses a high-barrier composite packaging film with an antibacterial function, which sequentially comprises a base layer, a nano composite barrier layer, an antibacterial functional layer and an outer protective layer from bottom to top, and the layers are tightly attached through a coated starch-based adhesive. According to the high-barrier composite packaging film with the antibacterial function, the cellulose nanowhiskers have the characteristics of high strength and high modulus and are mixed with the bio-based polylactic acid, so that the tensile strength and tear resistance of the bio-based polylactic acid can be remarkably improved, and the structural stability of the packaging film in the using process is guaranteed; nano titanium dioxide and nano cellulose aerogel are arranged in the nano composite barrier layer, so that the barrier property of the packaging film on oxygen and ultraviolet rays can be enhanced, and the packaging film also has a certain antibacterial effect; in addition, the nanocellulose aerogel has a loose porous structure, so that gas molecules can be effectively prevented from passing through, and the barrier property is further improved.

The invention provides a gamma-cyclodextrin-based metal organic framework composite material as well as preparation and application thereof. The metal organic framework composite material based on gamma-cyclodextrin comprises chitosan, gamma-CD-MOFs (Metal Organic Frameworks) and an active substance. The preparation method comprises the following steps: by taking chitosan as a film material base material, synthesizing gamma-CD-MOFs by utilizing a hydrothermal method, and then loading cinnamyl aldehyde with antibacterial property, 2-methoxycinnamyl aldehyde with ultraviolet light resistance and curcumin with an antioxidant effect into the gamma-CD-MOFs. And finally, mixing with chitosan with better film-forming property, and spraying on glass or the surfaces of fresh fruits. The gamma-CD-MOFs has the characteristic of slowly releasing bioactive substances, is non-toxic and is a material capable of being applied to food packaging.

The invention discloses a temperature-resistant waterproof polyurethane coating and a preparation method thereof, and belongs to the technical field of polyurethane coatings, the temperature-resistant waterproof polyurethane coating comprises the following components by mass: 80-90 parts of a polyurethane prepolymer, 1-1.5 parts of a reinforcing filler, 2-3 parts of a composite curing agent and 7-9 parts of polyether glycol; the polyurethane prepolymer is prepared by the following steps: stirring and mixing a fluororubber grafted solution and polyester polyol in a reaction kettle, heating to 70-80 DEG C under the protection of nitrogen, adding an isocyanate mixture, and stirring and reacting for 2-3 hours to obtain the polyurethane prepolymer; according to the temperature-resistant waterproof polyurethane coating prepared by the preparation method disclosed by the invention, the-NCO group is terminated, so that the coating has good stability before curing, is not easy to react with moisture in air and has good moisture resistance before curing, and the fluororubber, the reinforcing filler and the polyurethane waterproof coating are mixed, so that a cross-linked network of the cured polyurethane waterproof coating is enhanced; the mechanical property and the temperature resistance of the cured polyurethane waterproof coating are improved.

The invention discloses a preparation method of a multifunctional polyvinyl composite film and application of the multifunctional polyvinyl composite film in food preservation. The preparation method comprises the following steps: firstly, preparing Ag-coated MOF through a hydrothermal method, then uniformly dispersing the Ag-coated MOF and tannic acid into a carboxymethyl chitosan solution, and carrying out crosslinking modification on the Ag-coated MOF; and coating the prepared CMCS / TA / Ag (at) MOF mixed solution on a polyethylene film treated by oxygen plasma, and drying to form a film, so as to obtain the multifunctional polyethylene-based composite film. The CMCS and the TA are adopted to perform crosslinking modification on the Ag-coated MOF, so that the stability of the Ag-coated MOF can be further improved, and the release of silver ions is reduced. Compared with a common PE preservative film, the composite film prepared on the basis has better barrier capacity and mechanical property, and has antibacterial, anti-ultraviolet and anti-oxidation effects. The multifunctional preservative film is convenient to use and low in price, and has an important application prospect in the aspect of fresh-keeping packaging of meat products.

The invention belongs to the technical field of contact lenses, and provides a moisturizing contact lens containing a hyaluronic acid coating and a preparation method of the moisturizing contact lens. The preparation method comprises the following steps: carrying out ultrasonic mixing on a hydrophilic monomer, a siloxane monomer, a cross-linking agent and an initiator, injecting the mixed solution into a contact lens mold, and carrying out polymerization reaction to obtain a contact lens material; mixing the chitosan solution, the shellac acid solution, the hyaluronic acid solution and the vitamin E succinate solution to obtain a hyaluronic acid mixed solution; and soaking the contact lens material in the hyaluronic acid mixed solution, adding a cross-linking agent, curing, and drying to obtain the moisturizing contact lens containing the hyaluronic acid coating. The contact lens disclosed by the invention has excellent moisture retention, good light transmission performance, swelling performance and excellent mechanical property, the wearing comfort is remarkably improved, and the contact lens is suitable for being worn for a long time; the preparation method disclosed by the invention is environment-friendly and easy to industrialize.

The invention provides a preparation method of a bio-based smoke-suppressing, toxicity-reducing and flame-retardant coating, and relates to the field of flame retardance of wood materials and polyurethane foam materials. A wood material and a polyurethane foaming material are used as matrixes, a hydrolyzed collagen aqueous solution and a molecular sieve are added into a phytic acid aqueous solution to obtain a PDF solution, and the matrixes are sequentially soaked in CS and PDF solutions to obtain the bio-based flame-retardant coating. The preparation method can be widely applied to wood materials, polyurethane foam materials and the like. The method provided by the invention not only can greatly improve the flame retardant property of the matrix material and reduce the release amount of smoke and carbon monoxide, but also has the characteristics of high transparency, environmental friendliness, simplicity and convenience in operation, low cost and the like, and has the application prospect of large-scale preparation.

The invention discloses a preparation method of an intelligent anti-icing material, which comprises the following steps: preparing a humidity response precursor of the intelligent anti-icing material by using quaternized chitosan and E44 epoxy resin as raw materials, and mixing a PDMS prepolymer A, porous SiO2 nanoparticles and silicone oil to prepare an oil storage functional precursor of the intelligent anti-icing material; mixing the intelligent anti-icing material humidity response precursor and the intelligent anti-icing material oil storage functional precursor, adding an amine curing agent T31, a PDMS curing agent B and a cross-linking agent, and performing cross-linking curing to obtain the intelligent anti-icing material. When the intelligent anti-icing material is sprayed on the power transmission line, continuity of liquid on the surface of the power transmission line can be destroyed, spreading of ice on the surface of the power transmission line can be inhibited, ice nucleation sites are greatly reduced, ice crystal nucleation is inhibited, release and recovery of a lubricating layer are controlled by utilizing humidity sensitivity of the intelligent anti-icing material, and in the freezing and thawing cycle, the anti-icing effect is good. The service life of the lubricating layer is prolonged, and the intelligent anti-icing effect under the complex environment change is achieved.

The invention discloses an antibacterial sanitary towel packaging bag and a preparation method thereof. The antibacterial sanitary towel packaging bag comprises a base material layer, an antibacterial layer and a leakage-proof layer. The base material layer is prepared by blending modified polylactic acid, polybutylene adipate and the like and contains a degradation accelerant; the antibacterial layer contains antibacterial peptide-loaded nano montmorillonite, chitosan and the like, and loofah sponge fiber enhances slow release; and the leakage-proof layer is an ethylene-vinyl acetate copolymer and modified silicon dioxide blended film and is provided with breathable micropores. The preparation method comprises the steps of forming the base material layer, coating the antibacterial layer and the like, and process parameters of each layer are accurately controlled. According to the packaging bag, through cooperation of three layers, the bacteriostasis rate of the packaging bag on escherichia coli and staphylococcus aureus in 24 hours is higher than 99%, the degradation rate of the packaging bag in 83 days is higher than 88%, the oxygen permeability is 4.5-5.2 cm < 3 > / (m224h 0.1 MPa), and the packaging bag has the advantages of long-acting antibiosis, air permeability, leakage prevention, environmental protection, degradation and good mechanical properties, and meets the storage and use requirements of sanitary napkins.

The invention belongs to the technical field of straw resource utilization and agricultural degradable mulching films, and particularly discloses a water absorption and retention type straw-based biodegradable spraying mulching film and a preparation method thereof.Straw short fibers and biodegradable super absorbent resin are mixed through a V-shaped mixing machine according to a certain proportion, and a homogeneous dry powder formula is prepared; the preparation method comprises the following steps: preparing an adhesive aqueous solution with a certain concentration as a liquid-phase formula, synchronously spraying the dry powder formula and the liquid-phase formula according to a certain ratio by adopting a dry powder sprayer and a water mist spraying can respectively to prepare the continuous and stable mulching film, and preparing the mulching film through simple processes such as crushing, mixing and spraying without complicated equipment. The production cost is obviously lower than that of an existing synthetic polyester / natural polysaccharide mulching film, meanwhile, the problem of environmental pollution caused by straw incineration is solved, the agricultural sustainable development requirement is met, large-scale production is facilitated, the utilization rate of agricultural water resources is increased, and the mulching film has great application potential in arid / semi-arid regions.

The invention discloses a slow-release antibacterial and antioxidant composite preservative film and a preparation method thereof. The slow-release antibacterial and antioxidant composite preservative film is prepared from a chitosan matrix and Chuzhou chrysanthemum essential oil nano-emulsion loaded in the chitosan matrix, the Chuzhou chrysanthemum essential oil nano-emulsion comprises Chuzhou chrysanthemum essential oil, a surfactant and a cosurfactant, and the average particle size of the Chuzhou chrysanthemum essential oil nano-emulsion is smaller than 200 nm; the composite preservative film has the function of slowly releasing the Chuzhou chrysanthemum essential oil and shows antibacterial and antioxidant activity; the preparation method comprises the following steps: firstly preparing Chuzhou chrysanthemum essential oil into a nano-emulsion by adopting a nano-encapsulation method through a high-pressure homogenization method to form the Chuzhou chrysanthemum essential oil nano-emulsion, then embedding the Chuzhou chrysanthemum essential oil nano-emulsion into chitosan to prepare an active chitosan composite film, and finally applying the antibacterial coating material to food preservation. The antibacterial coating film not only can effectively inhibit pathogenic microorganism infection in berry storage and logistics transportation in a wider spectrum, but also can regulate physiological metabolism of picked berries, delay the senescence process and reduce loss of internal moisture.

The invention relates to the field of photo-thermal materials, and discloses a photo-thermal material composition for preparing a photo-thermal coating, application of the photo-thermal material composition, a photo-thermal composite film, a preparation method of the photo-thermal composite film and application of the photo-thermal composite film. The content weight ratio of the chitosan to the hydrophilic photo-thermal component to the optional auxiliary agent is 1: (0.1-15): (0-5), and a photo-thermal composite film prepared from the photo-thermal material composition provided by the invention is high in wettability and has relatively high light absorptivity, photo-thermal conversion efficiency and driving water evaporation rate.

According to the technical scheme, the copper-doped lasting antibacterial fresh-keeping material comprises a base body, an antibacterial nanofiber and copper ion loaded antibacterial hydrogel layer and a surface coating, the antibacterial nanofiber and copper ion loaded antibacterial hydrogel layer comprises antibacterial nanofibers and copper ion loaded antibacterial hydrogel, and the surface coating is coated with the antibacterial nanofibers and the copper ion loaded antibacterial hydrogel. The surface coating comprises microcapsules for contactable food products; the preparation method comprises the following steps: preparation of the copper-tannic acid coordination compound, preparation of the antibacterial nanofiber layer, preparation of the copper ion loaded antibacterial hydrogel, preparation of the substrate, interlayer compounding process, preparation of the sustained-release microcapsule coating, crosslinking and post-treatment. The humidity-responsive on-demand release of copper ions of the fresh-keeping material is realized, the antibacterial and fresh-keeping effects are good, the safety is high, and the environment-friendly effect is realized.

The invention discloses a multi-layer composite pipe as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The multi-layer composite pipe sequentially comprises a PEXB layer, a composite coating, a PTFE layer and a self-repairing layer from outside to inside, the composite coating comprises graphene, silver nanoparticles loaded on the surface of the graphene and a bio-based material crosslinked with the silver nanoparticles, and the self-repairing layer comprises polyurethane / epoxy resin microcapsules; the mass ratio of the graphene to the bio-based material to the silver nanoparticles in the composite coating is (85-89): 10: (1-5); the bio-based material is selected from one of carboxymethyl chitosan and sodium alginate. The multi-layer composite pipe has excellent chlorine resistance, antibacterial property, corrosion resistance and self-repairing function.

Polyhydric polymers may be converted to derivatives thereof by reaction with divinyl sulfone to provide vinyl sulfone substituted polymers, where the polymers may additionally be further derivatized, including crosslinked, and the crosslinked and non-crosslinked derivatives may be used in biomedical and other applications.

The invention belongs to the technical field of label paper, and provides oil-proof label paper and a preparation method thereof.The oil-proof label paper sequentially comprises an oil-proof layer, a plane material layer and a release layer from top to bottom; the oil-proof layer is prepared from the following raw material components in parts by weight: 25 to 40 parts of modified chitosan, 2 to 5 parts of modified polyvinyl alcohol, 3 to 6 parts of nano silicon dioxide, 0.5 to 2 parts of polyacrylamide and 0.05 to 1 part of carboxymethyl cellulose. The preparation method of the oil-proof label paper comprises the following steps: mixing the modified chitosan, the modified polyvinyl alcohol, the nano silicon dioxide, the polyacrylamide and the carboxymethyl cellulose in proportion, and uniformly stirring to obtain a mixed solution; and uniformly coating one surface of the surface material layer with the mixed solution, drying after coating is completed, and compounding the other surface, which is not coated, of the surface material layer on the release layer after drying to prepare the oil-proof label paper, and the prepared label paper has excellent oil-proof and water-proof effects and can be widely applied to the field of food packaging.

A method of coating a polymer surface is provided, comprising providing a polymer having a surface, optionally treating at least a portion of the polymer surface with an oxidizing agent, treating at least a portion of the polymer surface with a composition comprising a polysaccharide, an oligosaccharide, a polyol, or a mixture thereof, and incubating the treated polymer with the composition for a period of time. Also disclosed are polymers comprising such coatings, containers comprising such coated polymers, and medical devices comprising such polymers.

The invention provides a modified carboxymethyl chitosan-based conductive composite material modified electrode as well as a preparation method and application thereof, and belongs to the technical field of heavy metal detection sensors. The preparation method of the modified carboxymethyl chitosan-based conductive composite material modified electrode comprises the following steps: dissolving carboxymethyl chitosan, adding an activator for activation, and then adding L-methionine for a coupling reaction to obtain an L-methionine graft modified carboxymethyl chitosan derivative; dispersing the L-methionine graft modified carboxymethyl chitosan derivative, polypyrrole and a multi-walled carbon nanotube in a solvent to obtain a dispersion liquid; and coating the surface of a substrate electrode with the dispersion liquid, and drying to obtain the modified carboxymethyl chitosan-based conductive composite material modified electrode. The electrochemical sensor constructed by the electrode modified by the modified carboxymethyl chitosan-based conductive composite material realizes simultaneous determination of Cd < 2 + >, Pb < 2 + > and Cu < 2 + >.

The invention discloses a protective coating treating agent, a protective coating treating fluid, modified forage and a preparation method and application thereof, and belongs to the technical field of ecological engineering. The protective coating treating agent comprises a first component, a second component and a third component in a mass ratio of 10: (0.5-2.5): (1-3), the first component is a natural polymer film-forming material; the second component is a plant-derived functional anti-degradation agent; and the third component is a natural mineral particle reinforcing agent. The protective coating treating agent containing the components is prepared into a protective coating treating fluid, and then the protective coating treating fluid is coated on the surface of forage to form a protective coating, so that the aging resistance of the straw checks in environments of high temperature, strong ultraviolet rays, sand erosion and microbial erosion can be remarkably improved, the service life of the straw checks is prolonged, and the service life of the straw checks is prolonged. And the operation and maintenance cost of ecological restoration engineering is reduced. The straw checkerboard with the protective coating can be widely applied to ecological engineering construction such as treatment of railways, highways and sand source areas in arid and windy sand areas.

The invention provides an anti-corrosion liquid film and a planting method for climate intelligent agriculture in a semi-arid windy desert area, and belongs to the technical field of desertification cultivated land control and desertification control. The anti-corrosion liquid film is prepared from humic acid, sodium alginate, carboxymethyl chitosan, polyethylene glycol, guar gum and water. The anti-corrosion liquid film has good anti-corrosion and soil moisture preservation capacity, can promote soil to form aggregates and improve the soil structure, has good film forming performance and tensile strength, is easy to degrade and does not cause pollution to the environment. After previous crops are harvested, fertilization, ridging and grass seed sowing are carried out, then the anti-corrosion liquid film is sprayed, and the crops are planted in spring according to the soil moisture content. By means of the method, the emergence rate and yield of desertification farmland crops can be increased, meanwhile, climate environment changes are effectively coped, the soil organic matter content and the soil porosity are increased, economic benefits can be increased while wind prevention and sand fixation are achieved, and the purposes of improving desertification degradation, recarburizing, fertilizing and disaster prevention and reduction are achieved.

The invention provides a water-based damping coating and a preparation method thereof, and relates to the technical field of coatings. An amine compound reacts with polyurethane to form a urea bond, so that a highly-crosslinked polyurethane network structure is formed, and the damping performance is enhanced; meanwhile, a modified nano material is introduced to increase the internal friction force of the material, and a dispersed multi-phase structure can also be formed in a polyurethane matrix, so that crack expansion and energy transfer are effectively hindered, and more mechanical energy is consumed; in the introduced surface acid etching hindered phenol / epoxy microspheres, large groups in an antioxidant AO-80 structure can generate internal friction in a deformation process so as to increase energy dissipation; the epoxy resin is used as a matrix of the microspheres, and can form relatively strong interface interaction with a polyurethane matrix, so that energy can be further dissipated, and the damping effect can be enhanced; the surface roughness of the hindered phenol / epoxy microspheres is increased through surface acid etching, and the physical binding force between the microspheres and a polyurethane matrix is enhanced.

The invention relates to the field of packaging materials, and particularly discloses a transparent high-barrier film and a preparation method thereof. The transparent high-barrier film comprises a matrix film and chitin nanofiber films positioned on two sides of the matrix film, the matrix film is prepared from the following raw materials in parts by weight: 50 to 80 parts of PBAT resin, 20 to 30 parts of PLA resin, 25 to 40 parts of modified poly epsilon-caprolactone, 0.5 to 1 part of compatilizer, 0.1 to 1 part of antioxidant, 15 to 25 parts of filler and 0.5 to 0.8 part of nucleating agent; the modified poly (epsilon-caprolactone) is prepared from the following raw materials in parts by weight: 80 to 100 parts of epsilon-caprolactone, 3 to 5 parts of cellulose nanofiber, 2.5 to 3 parts of halloysite aluminum-magnesium-loaded hydrotalcite, 100 to 120 parts of ionic liquid and 1 to 2 parts of catalyst. The transparent high-barrier film disclosed by the invention not only has excellent oxygen and water vapor barrier properties, mechanical properties and good biodegradability, but also has the light transmittance of 90% or above.

The invention belongs to the technical field of biological fouling protection, and particularly relates to an environment-friendly adhesive hydrogel antifouling coating which is prepared by the following steps: grafting a catechol group to an acryloyl compound with double bonds through acylation reaction to obtain a dopamine-acrylamide compound; the preparation method comprises the following steps: carrying out copolymerization reaction on an acrylamide derivative and a dopamine-acrylamide compound in a water environment to obtain an acrylamide derivative copolymer; and mixing the chitosan and the acrylamide derivative copolymer to obtain the environment-friendly adhesive hydrogel antifouling coating. According to the invention, polyacrylamide and catechol are introduced into a chitosan system at the same time to form a chitosan-polyacrylamide-catechol ternary synergistic network, and the chitosan-polyacrylamide-catechol ternary synergistic network has the effects of self-repairing, high toughness, strong adhesion and intelligent response.

The invention discloses a sodium-ion battery diaphragm, a preparation method thereof and a sodium-ion battery, and belongs to the technical field of sodium-ion batteries, the sodium-ion battery diaphragm comprises a glass fiber diaphragm and a modified coating coated on one side of the glass fiber diaphragm; the modified coating faces the negative electrode side of the sodium ion battery; the modified coating is prepared from the following raw materials in parts by mass: 10 parts of chitosan, 0.4 to 0.6 part of cellulose nanofiber, 0.02 to 0.04 part of cross-linking agent and 90 to 150 parts of solvent. A large number of polar groups in the chitosan can adsorb sodium ions through electrostatic interaction, so that the difference of local current density is reduced, and the growth of sodium dendrites is effectively inhibited; the cellulose nanofiber is used as a rigid filler and is compounded with the chitosan, so that a compact and uniform network structure can be formed, the mechanical strength of the diaphragm is improved, penetration of sodium dendrites is directly hindered, the pore size of the diaphragm is adjusted, uniform transmission of ions is facilitated, and the cycling stability of the sodium ion battery is improved.

The invention relates to the field of biomimetic materials, in particular to a biomimetic self-cleaning anti-fouling aquaculture net cage material, a preparation method and application of the biomimetic self-cleaning anti-fouling aquaculture net cage material. 0.5 to 2.0 parts by weight of a carboxylated graphene nanosheet; 2.0 to 5.0 parts by weight of nitrogen-doped titanium dioxide nanoparticles; 1.0 to 3.0 parts by weight of silica nanoparticles; 5.0 to 10.0 parts by weight of calcium ion cross-linked modified sodium alginate; 1.0 to 3.0 parts by weight of octadecyl trichlorosilane; 0.5 to 1.5 parts by weight of lauryl sodium sulfate; through the synergistic effect of a double bionic structure and enhanced photocatalysis, the effective inhibition on attachment of various organisms is realized, and the inhibition rate on attachment organisms such as algae, bacteria and barnacles reaches 75% or above.

The invention relates to the technical field of medicine packaging materials, and discloses a preparation technology of a high-barrier-property composite film for medicine. Comprising the steps of preparation of a degradable base material, coating of a bio-based pressure-sensitive adhesive, distribution of a gradient inhibitor, interface ion exchange activation, construction of an ion immobilization network, temperature and humidity gradient control curing, formation of a phase interface dehydration protection layer and the like. Through a dual action mechanism of pressure-sensitive adhesion and ion exchange and a synergistic effect of biological activity inhibition and ion migration blocking, efficient compounding of a degradable base material and an inorganic barrier layer is realized, and the technical problems of both environmental protection property and high barrier property, attenuation of interface bonding stability and long-term use performance and the like are solved.

The invention relates to the technical field of leather auxiliaries, and discloses a modified negative oxygen ion leather finishing agent and a preparation method thereof.The modified negative oxygen ion leather finishing agent is obtained by adding negative oxygen ion nanometer liquid, modified polyurethane, epoxy chitosan, polyethylene glycol and water into a stirrer and stirring. In the stirring process, a terminal hydroxyl group in the modified polyurethane and an epoxy group in the epoxy group chitosan are subjected to a ring-opening reaction and are cross-linked with each other, and a stable molecular contact network is formed and is better adsorbed on the surface of leather, so that the leather finishing agent is better adsorbed on the surface of the leather. The sulfur element and the phosphorus element in the modified polyurethane have better flame-retardant effects, and form a flame-retardant system together with a chitosan molecular structure in the epoxy chitosan. Chitosan and quaternary ammonium salt in the epoxy chitosan have a relatively good antibacterial effect.

The invention relates to the field of total heat exchange membranes for fresh air systems, in particular to a method for preparing a nanoparticle / polymer total heat exchange membrane with the assistance of a dispersing agent. A coupling agent, a dispersing agent, a hydrophilic oligomer and the modified inorganic nanoparticles are subjected to a grafting reaction in a solution, the obtained grafted inorganic nanoparticles are dispersed in a film forming component through the dispersing agent and ultrasound, and a uniformly dispersed film casting solution is obtained; and coating on a base material and drying to obtain the nano-particle / polymer total heat exchange membrane prepared by the aid of the dispersing agent. The prepared total heat exchange membrane is high in surface nanoparticle distribution uniformity, high in air blocking performance, high in moisture permeability after being grafted with the hydrophilic polymer and improved in heat exchange efficiency, and has wide application prospects in the fields of total heat exchange for a fresh air system, air dehumidification and the like.

The invention discloses a multi-layer composite pipe as well as a preparation method and application thereof, and relates to the technical field of plastic pipelines. The multi-layer composite pipe sequentially comprises an anti-freezing outer layer, a bonding layer and a pressure-bearing inner layer from outside to inside, and the anti-freezing outer layer comprises PPR; nanoparticles; an elastic body; the bonding layer comprises a gradient copolymer, and preparation raw materials of the gradient copolymer comprise PP, PE and a silane coupling agent; the gradient copolymer sequentially comprises a first gradient layer, a second gradient layer and a third gradient layer in the thickness direction of the bonding layer, the mass ratio of PP to PE in the first gradient layer is 7: 3-8: 2, the mass ratio of PP to PE in the second gradient layer is 4: 6-5: 5, and the mass ratio of PP to PE in the third gradient layer is 2: 8-3: 7; and the pressure-bearing inner layer comprises PERT and peroxide. The multi-layer composite pipe provided by the invention has excellent frost crack resistance and long-term hydrostatic stability.

The invention discloses a full-biodegradable bamboo fiber film material and a preparation method thereof. The full-biodegradable bamboo fiber film material is composed of a bamboo fiber composite matrix, a biodegradable reinforcing system and a multifunctional cross-linking agent. The bamboo fiber composite matrix is a mixture of bamboo pulp fiber pretreated by supercritical CO2 and microcrystalline cellulose; the biodegradation enhancing system is composed of nano calcium carbonate-montmorillonite composite particles and a polylactic acid-glycolic acid copolymer, and the composite particles are modified by a silane coupling agent; the multifunctional cross-linking agent is an esterification product of citric acid and glycerol. The preparation method comprises the steps of bamboo fiber supercritical pretreatment, composite reinforced particle preparation, melt extrusion, two-way stretching, gradient heat setting and the like, and finally the antibacterial surface layer is formed through chitosan surface treatment. The material realizes the balance of biodegradability and mechanical properties through raw material synergy and process optimization, and is suitable for the fields of packaging, agricultural coverage and the like.

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a carbon-coated aluminum foil coating and a preparation method thereof. The invention aims to solve the problem of contradiction between high conductivity and strong adhesive force of the current carbon-coated aluminum foil coating. According to the invention, a multi-stage dimensional composite conductive network is taken as a design core, and the conductive performance of the coating is improved through a ternary composite system formed by conductive carbon black, one-dimensional carboxylated multi-walled carbon nanotubes and two-dimensional sulfonated graphene oxide; the binder adopts a bio-based water-based system and is formed by compounding carboxylated cellulose nanocrystals and quaternized chitosan, and a compact and tough bonding network layer is formed through electrostatic interaction and hydrogen bond combination; the conductive adhesive is excellent in conductivity and strong in adhesive force, the preparation process is environment-friendly and efficient, and the contradictory problem that the conductivity and the adhesive force are difficult to consider at the same time in the prior art is solved.