2064 results about "Polylactic acid" patented technology

The invention provides a high-hydrophobicity anti-pollution flashover coating and a preparation method thereof, and relates to the field of coatings. The silicone rubber composition is prepared from the following raw materials in parts by weight: 80 to 100 parts of hydroxyl-terminated polydimethylsiloxane; 5 to 15 parts of modified nano silicon dioxide; 10 to 30 parts of a composite self-repairing microcapsule; 10 to 25 parts of a flame retardant; 3-8 parts of a cross-linking agent; 0.5-2 parts of a catalyst; 1-5 parts of an accelerant; 40 to 100 parts of a solvent; the modified nano silicon dioxide is fumed silica subjected to surface treatment by a fluorine-containing silane coupling agent and a platinum catalyst; the capsule wall of the composite self-repairing microcapsule is a polylactic acid-glycolic acid copolymer, and the capsule core of the composite self-repairing microcapsule is a mixed solution of a hydroxyl-terminated polydimethylsiloxane oligomer and methyltris (methylethylketoximino) silane. The coating has excellent hydrophobicity, weather resistance and targeted repair function.

The invention relates to the technical field of thermoplastic vulcanizates, and discloses a TPV sealing material and a preparation method thereof. The TPV sealing material is prepared from the following raw materials in parts by weight: 10 to 30 parts of PP resin, 40 to 60 parts of EPDM rubber, 10 to 20 parts of polylactic acid, 15 to 25 parts of filler, 0.5 to 1.5 parts of vulcanizing agent, 0.3 to 1.5 parts of vulcanization accelerator, 5 to 10 parts of compatilizer, 1 to 4 parts of modified heat stabilizer and 0.5 to 3 parts of modified anti-aging agent. Through preparation of the modified heat stabilizer, structural damage or sealing failure caused by thermal aging of a system can be reduced, and the service life of the sealing material is greatly prolonged; the preparation of the modified anti-aging agent can effectively resist the corrosion of environmental factors such as thermal oxidation and ozone to the system, and prevent the problems of cracking, hardening, elasticity attenuation, sealing failure and the like of the sealing material after long-term use.

The invention discloses a biodegradable polylactic acid composite material and a preparation method thereof, and relates to the technical field of polylactic acid materials. The method comprises the steps that firstly, chitosan activated through hydrochloric acid is subjected to graft modification through a KH550 silane coupling agent, meanwhile, nano-zinc oxide is subjected to surface modification through stearic acid, the chitosan and the nano-zinc oxide are mixed, spray drying is conducted, and antibacterial composite powder is prepared; the preparation method comprises the following steps: performing hydrochloric acid activation and KH570 silane coupling agent modification on nano silicon dioxide, performing hydroxypropylation modification on alkali lignin, and performing reflux crosslinking reaction on the modified alkali lignin, KH570 modified nano silicon dioxide, polycaprolactone, methyl methacrylate and azodiisobutyronitrile to prepare a heat-resistant reinforcer; uniformly mixing polylactic acid, poly (butylene succinate), the antibacterial composite powder, the heat-resistant reinforcer, tributyl citrate, polyethylene glycol and talcum powder, and extruding and granulating by using a twin-screw extruder to obtain the heat-resistant antibacterial material. The composite material prepared by the invention has excellent antibacterial property, heat resistance and biodegradability.

The invention relates to the technical field of food packaging materials, in particular to a cerium dioxide nano-enzyme modified antibacterial coating and application of the cerium dioxide nano-enzyme modified antibacterial coating in food packaging. The biomimetic mineralization layer comprises the following components in percentage by weight: 35-45% of a green base material, 8-12% of dopamine modified yttrium-doped cerium dioxide nano-enzyme, 4-6% of a composite antibacterial agent, 3-4% of a natural cross-linking agent, 2-3% of a degradable plasticizer, 1-2% of a biomimetic mineralization layer precursor and the balance of deionized water, the green base material is a blend of a chitosan-polyethylene glycol graft and polylactic acid; the doping amount of Y3 in the nano enzyme is 3-4at%. The antibacterial agent is excellent and lasting in antibacterial effect, has no migration risk of the antibacterial agent, and can guarantee food safety; a green base material and a degradable plasticizer are adopted, so that natural degradation is realized, and environmental pollution is avoided; the mechanical property is good, the aging resistance is realized, and the oxygen barrier property is strong; the food packaging box is suitable for various foods, effectively prolongs the shelf life, and meets the requirement of green packaging.

The invention provides a low-temperature-impact-resistant food packaging material and a preparation method and application thereof.The low-temperature-impact-resistant food packaging material is prepared from, by mass, 100 parts of polylactic acid, 1-10 parts of modified layered double hydroxide and 5-40 parts of hyperbranched polyester; wherein the modified layered double hydroxide is obtained by treating layered double hydroxide with a composite anionic surfactant and then treating the treated layered double hydroxide with an organic cationic compound with a long alkyl chain; the composite anionic surfactant comprises a first anionic surfactant and a second anionic surfactant; wherein the first anionic surfactant comprises sodium dodecyl sulfate; the second anionic surfactant comprises a sulfonate anionic surfactant containing an amido bond and a catechol structure. Through the formula design, the impact toughness of the material at low temperature can be improved while the mechanical property of polylactic acid is maintained, and the material can be suitable for the field of food packaging.

The invention relates to the field of oral cavities, and particularly discloses a lasting antibacterial type composite tooth socket for medicine carrying and a preparation method thereof.The lasting antibacterial type composite tooth socket comprises an adsorption layer and an antibacterial membrane layer, the adsorption layer is used for adsorbing oral cavity treatment liquid medicine, and the antibacterial membrane layer comprises a nano-silver antibacterial layer and a chitosan antibacterial layer; the preparation method comprises the following steps: mixing a tea polyphenol-polylactic acid composite solution, a nano-silver-carboxylation modified cellulose compound and a polyvinyl alcohol solution, and carrying out electrostatic spinning to prepare a nano-silver antibacterial fiber membrane, so as to form the nano-silver antibacterial layer; mixing chitosan with hot water, adding cinnamyl aldehyde, glycerol and boric acid, stirring to obtain a mixed solution, coating one side of the nano-silver antibacterial layer with the mixed solution, and curing to form a chitosan antibacterial layer; the adsorption layer is attached to the side, away from the chitosan antibacterial layer, of the nano-silver antibacterial layer, and then the lasting antibacterial type composite tooth socket for carrying the medicine is prepared through hot-pressing compounding. The drug-loaded composite tooth socket has the characteristic of further improving the antibacterial property and the antibacterial durability of the drug-loaded composite tooth socket.

The invention relates to the technical field of degradable materials, and discloses a water-soluble degradable fiber and a preparation method thereof. The water-soluble degradable fiber disclosed by the invention is prepared by taking polylactic acid as a main matrix, adding modified sodium lignin sulfonate, polyvinyl alcohol and polyethylene wax, blending, carrying out melt extrusion, and carrying out melt spinning. The fiber has water solubility, degradability, sand carrying performance and salt resistance, and has a good application prospect in a fracturing fluid used in a well drilling fracturing process based on the advantages of water solubility, degradability, sand carrying performance and salt resistance.

The present invention relates to a lid film for airtight sealing of beverage capsules, in particular coffee capsules, comprising excellent barrier properties against gas ingress, water or humidity and oxygen: i.) at least one layer of paper, ii.) at least one layer containing polylactic acid, iii.) at least one layer of metallization, iv.) at least one sealing layer containing at least one thermoplastic polymer made from glucose, lignin or cellulose.

The invention discloses environmentally degradable plastic as well as a preparation method and application thereof, and belongs to the technical field of degradable plastic. The degradable modified plastic is prepared from the following raw materials: polylactic acid, poly (butylene terephthalate)-adipate, modified thermoplastic starch, modified cellulose, poly (butylene succinate), epoxidized soybean oil, polyvinyl alcohol, glycerol monolaurate and ethylenediaminetetraacetic acid. Wherein the modified thermoplastic starch is obtained by thermoplastic modification of starch through a plasticizer and modification of castor oil and toluene diisocynate; the modified cellulose is obtained by modifying cellulose acetate with chitosan. By regulating and controlling the types and proportions of the raw materials for preparing the plastic, the plastic with excellent degradation performance and mechanical performance can be obtained, the shopping bag is prepared from the plastic, the loading capacity can be remarkably improved, the plastic is easily degraded by microorganisms in the environment after being discarded, and environmental pollution is avoided.

The invention discloses a copper-clad plate material containing elastomer resin and a preparation method of the copper-clad plate material, and belongs to the technical field of new materials. The method comprises the following steps: mixing a styrene-butadiene-styrene block copolymer with polybutadiene rubber, adding nano-montmorillonite, and carrying out intercalation modification through hexadecyl trimethyl ammonium bromide to prepare nano-modified elastomer resin; the preparation method comprises the following steps: mixing polybutylene terephthalate with nano silicon dioxide, and carrying out surface modification by gamma-aminopropyltriethoxysilane and hexamethyldisilazane to obtain a resin matrix; mixing the two phases, adding citric acid, and carrying out microwave heating and high-shear dispersion to obtain a discrete material; carrying out hot pressing on the dispersion, adding polyurethane and polylactic acid, uniformly mixing, adding polydimethylsiloxane and sodium dodecyl benzene sulfonate, and curing to obtain a cured product; and coating the surface of the cured product with a nano-copper layer. The material has the characteristics of high peel strength, low dielectric loss, low water absorption and low thermal expansion, and is suitable for the field of high-speed low-loss copper-clad plates.

The invention discloses a recyclable lawn and a preparation method thereof, and belongs to the technical field of artificial turfs. The lawn sequentially comprises artificial grass yarns, a base cloth layer and a back glue layer from top to bottom, the artificial grass yarns and the base cloth layer are made of polyolefin; the back adhesive layer is prepared from the following components in parts by weight: 4 to 8 parts of polyolefin elastomer, 10 to 20 parts of olefin block copolymer, 20 to 30 parts of hydrogenated styrene-butadiene copolymer, 8 to 12 parts of styrene-isoprene copolymer, 10 to 12 parts of butadiene-styrene rubber, 2 to 6 parts of ethylene-acrylic acid copolymer, 15 to 30 parts of plasticizer, 0.1 to 0.4 part of antioxidant, 3 to 6 parts of compatilizer and 2 to 4 parts of modified filler; according to the lawn, the artificial grass yarns, the base cloth layer and the gum layer are similar in component, so that the lawn can be conveniently and integrally recycled subsequently, the utilization rate of the lawn gum is increased, and resource waste is reduced.

The invention discloses a high-barrier degradable vegetable and fruit preservative film based on multi-layer compounding and a preparation method thereof, belongs to the technical field of food packaging materials, and aims to solve the technical problem that the barrier property, the mechanical property and the antibacterial property of the degradable vegetable and fruit preservative film in the prior art need to be further improved. The degradable vegetable and fruit preservative film comprises a first layer, a second layer and a third layer which are sequentially laminated, and the first layer is prepared from, by weight, 65-75 parts of polylactic acid, 4-8 parts of maleic anhydride grafted polylactic acid, 2-4 parts of modified carbon nitride, 1-3 parts of alizarin microcapsules, 3-6 parts of modified lignin and 1-2 parts of auxiliary additives; through the synergistic effect of the modified carbon nitride, the alizarin microcapsules and the modified lignin, the barrier property, the mechanical property and the antibacterial property of the degradable vegetable and fruit preservative film are further improved.

The invention provides a heat insulation and energy storage polylactic acid-based composite material, the polylactic acid-based composite material is a three-layer composite material, and comprises a surface layer, an energy storage layer and a heat conduction buffer layer, the surface layer comprises high-crystallinity polylactic acid, mesoporous SiO2, micron hollow glass beads, nano TiO2, nano ZnO and an antioxidant 1010, the energy storage layer comprises low-crystallinity polylactic acid and phase change microcapsules, and the heat conduction buffer layer comprises a heat conduction buffer layer. The composite material comprises polylactic acid, hydroxylated carbon nanotubes, polycaprolactone, tributyl citrate and an antioxidant 1010, and the composite material comprises medium-crystallinity polylactic acid, hydroxylated carbon nanotubes and polycaprolactone. The polylactic acid-based composite material prepared by the preparation method disclosed by the invention realizes the balance of heat insulation, energy storage and mechanical properties.

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 invention discloses a biodegradable flexible conductive high-hydrophobicity sensor substrate and a preparation method and application thereof.The preparation method comprises the steps that a polylactic acid electrostatic spinning solution and a chitosan / polyethylene oxide mixed electrostatic spinning solution are prepared on the basis of a safe and non-toxic food-grade material; the preparation method comprises the following steps: sequentially spinning by adopting an electrostatic spinning technology to form a sandwich structure flexible substrate, transferring a carbon nano tube conductive film, and tightly attaching the carbon nano tube conductive film to the surface of a polylactic acid layer of the sandwich structure substrate, thereby finally obtaining the flexible conductive high-hydrophobicity composite substrate. According to the invention, a hydrophobic-hydrophilic-hydrophobic sandwich structure is constructed through multi-layer electrostatic spinning, and a surface carbon nanotube conductive layer is cooperated, so that the substrate has high hydrophobicity, excellent conductivity and flexible tensile property. The preparation method has the characteristics of controllable process, low cost and environmental friendliness, and the obtained substrate is expected to have wide application prospects in the fields of food packaging, sensor substrates, intelligent wearing, health monitoring and the like.

The invention relates to the technical field of fluid-state solidified soil, and particularly discloses high-fluid-state solidified soil and a preparation method thereof. The high-flow-state solidified soil is prepared from the following raw materials in parts by weight: 1100 to 1200 parts of recycled aggregate, 700 to 800 parts of river sand, 100 to 130 parts of a curing agent, 18 to 22 parts of a polycarboxylic acid water reducing agent, 75 to 85 parts of solidified soil repairing microcapsules and 55 to 95 parts of water, the solidified soil repairing microcapsule is prepared by taking polylactic acid and nano calcium carbonate grafted polyethylene glycol as composite membrane materials, and wrapping and forming sulphoaluminate cement paste through an emulsification-solidification method. The solidified soil repairing microcapsules are introduced into the solidified soil, pores in an interface transition area can be filled, micro cracks can be repaired, and the durability of the solidified soil is improved.

The invention discloses a film coating process and equipment in a narrow-mouth container, and relates to the technical field of paper container preparation, and the equipment comprises a film coating system, a mold closing system, a vacuum system, a heating system, an adjusting system and a control system. The polylactic acid air bag is adopted as a film covering raw material, so that the produced paper-plastic product has biodegradability, the produced product can be naturally degraded, and the problems that the paper-plastic product is difficult to recycle and treat are solved. According to the invention, the polylactic acid air bag is attached to the inner wall of the molded pulp container by directly utilizing the characteristic that polylactic acid becomes soft and generates colloid after being heated, so that the influence on the volume of the container can be reduced as much as possible, and the environment-friendly characteristic is better. The environment-friendly characteristic and the physical and mechanical properties of the paper mold can be obviously improved, and the application range of the paper mold is expanded. By optimizing and innovating a film laminating process and equipment, a more environment-friendly liquid container can be prepared, and the development and the use of the paper pulp molded container are more in line with the requirements of sustainable development.

The preparation method comprises the following steps: S1, adding silicon powder, graphite, a carbon source and a pore-forming agent into a solvent to obtain slurry; the pore-forming agent comprises ammonium citrate and polylactic acid; s2, performing spray drying on the slurry to obtain precursor microspheres; s3, the precursor microspheres are subjected to first-stage low-temperature oxidation to form macropores, second-stage medium-temperature melting to form mesopores, third-stage high-temperature carbonization and cooling shaping, the heat preservation temperature of the first-stage low-temperature oxidation is 180-200 DEG C, the heat preservation temperature of the second-stage medium-temperature melting is 340-360 DEG C, the heat preservation temperature of the third-stage high-temperature carbonization is 800-900 DEG C, and the gradient pyrolysis dual-pore-forming silicon-carbon negative electrode material is obtained. Through combined use of ammonium citrate and polylactic acid and control of gradient pyrolysis conditions, synergistic distribution of double-peak gradient pores is formed, and effective improvement of the first effect and the cycle performance can be realized.

The invention relates to the field of high polymer material processing, in particular to an in-situ elastomer fiber toughened polylactic acid composite material and a preparation method thereof. The in-situ elastomer fiber toughened polylactic acid composite material provided by the invention comprises a polylactic acid matrix and elastomer fibers dispersed in the polylactic acid matrix, and the elastomer fibers are formed in the polylactic acid matrix in situ by a fiber forming phase; the fiber forming phase is a polyolefin elastomer, a polyurethane elastomer or a styrene elastomer; the polylactic acid matrix is formed by polylactic acid, and the mass ratio of the polylactic acid to the fiber forming phase is (80-100): (1-20). The elastomer added in the in-situ elastomer fiber toughened polylactic acid composite material prepared by the invention forms fibers in situ, so that the stress of a crack propagation tip is effectively absorbed, and the toughness of polylactic acid can be effectively improved under the condition of maintaining the strength and modulus of polylactic acid.

The invention discloses a modified polylactic acid high-temperature-resistant degradable composite material and a preparation method thereof, and relates to the technical field of degradable materials. The modified polylactic acid high-temperature-resistant degradable composite material at least comprises the following raw materials in parts by mass: 70-80 parts of polylactic acid; 15 to 25 parts by mass of a lignin-polylactic acid-polycaprolactone block copolymer; 5 to 10 parts by mass of poly (butylene adipate-co-terephthalate); 2-5 parts by mass of stearic acid modified nano silicon dioxide; 0.3 to 0.8 part by mass of an anti-hydrolysis agent; and 0.2 to 0.5 part by mass of an antioxidant. According to the prepared modified polylactic acid high-temperature-resistant degradable composite material, the mechanical property and the high temperature resistance of the polylactic acid composite material are improved, the degradation rate can be regulated and controlled through the proportion of all the components, and the use requirements of different scenes are met.

The invention provides a ternary synergistic flame retardant suitable for a polylactic acid composite material and a preparation method thereof. The ternary synergistic flame retardant comprises ternary components of magnesium hydroxide, zinc oxide and titanium dioxide, the ternary component is subjected to surface modification through a silane coupling agent solution containing an epoxy group, the mass ratio of magnesium hydroxide to zinc oxide to titanium dioxide is 4: 1.5: 1-5: 2: 1, and the ternary component is used for maintaining the mechanical property of polylactic acid and achieving the synergistic effect of flame retardance and smoke suppression at the same time. According to the polylactic acid composite material prepared by the invention, the limit oxygen index is increased to 28.85% from 19.91%, the increase amplitude is about 45%, and the UL-94 V-0 grade is reached; the maximum smoke density is reduced from 287 to 198, the reduction amplitude is about 31%, and the flame retardant efficiency of the material and the visibility in the combustion process are remarkably improved. The addition amount of the ternary synergistic flame retardant is controlled in a range of 15-25%, an excellent flame retardant effect can be obtained, the addition amount is greatly reduced compared with that of a single magnesium hydroxide system (generally, the addition amount needs to be larger than or equal to 40%), and the mechanical property loss caused by high filling is effectively avoided.

A liner mat for waste pit management and drilling fluid recycling at well sites is described. The liner mat includes an adsorbent layer and a base layer. The adsorbent layer includes chitosan and polyhydroxyalkanoate (PHA). The base layer includes polylactic acid (PLA). In some cases, the base layer includes hydroxyapatite (HAp). The adsorbent layer contacts the drilling fluid. The adsorbent layer can mitigate microbial growth and adsorbs at least a portion of pollutants from the drilling fluid. The base layer provides structural support and resistance against mechanical stress and tearing.

The invention belongs to the technical field of high polymer materials, and particularly relates to a polylactic acid blended composite material applied to automotive interiors and a preparation method thereof. The raw material of the material is polylactic acid modified ionomer or polylactic acid modified copolymer; a biodegradable polyester or elastomer; a chain extender; an anti-hydrolysis agent; an antioxidant; a nucleating agent; and a lubricant. The preparation method comprises the following steps: carrying out vacuum drying on the polylactic acid ionomer or the polylactic acid modified copolymer and the biodegradable polyester or the elastomer; uniformly mixing the dried polylactic acid ionomer or polylactic acid modified copolymer, biodegradable polyester or elastomer, a chain extender, an antioxidant and a lubricant to obtain a mixture; melting, blending and extruding the mixture; water in the material is pumped out at the tail end of an extruder in a vacuumizing mode, and the polylactic acid blending composite material is obtained after the procedures of water cooling, grain-sized dicing and drying. The material disclosed by the invention has excellent characteristics of high rigidity, high toughness, heat resistance, ultraviolet resistance, antibacterial property and the like, and can be applied to the field of automotive upholstery.

The invention discloses a jacquard vamp material based on bio-based degradable polylactic acid (PLA) and a preparation method thereof, and relates to the technical field of shoe materials. The jacquard vamp material is of a three-layer jacquard structure formed by integrally weaving PLA composite filaments through a jacquard warp knitting machine. The PLA composite filament is prepared from the following raw materials in parts by weight: 80-95 parts of polylactic acid (PLA) slices, 5-15 parts of poly (butylene adipate / terephthalate) (PBAT), 3-8 parts of a flexibilizer, 1-3 parts of a compatilizer, 0.5-2 parts of an anti-hydrolysis agent and 0.5-1.5 parts of a lubricant. According to the invention, the bio-based PLA is used as a main raw material and is matched with degradable auxiliaries such as PBAT, so that the whole vamp material can be completely biodegraded under a composting condition, the problem of environmental pollution of a traditional vamp is fundamentally solved, and meanwhile, through blending modification of PBAT and the flexibilizer, the flexibility and impact resistance of the PLA material are remarkably improved, and the vamp material has good application prospects. The requirements of the vamp material on softness, wear resistance and durability can be met.

The invention discloses a degradable preservative film and a preparation method thereof. The film takes nano chitosan / agarose in a ratio of 1: 1 as a matrix, contains 0.5-5wt% of PVA (Polyvinyl Alcohol), 1-4wt% of protein powder or starch, 0.2-3wt% of tea polyphenol / carvacrol, 5-20wt% of glycerol and optional 5-15wt% of polylactic acid, and is cross-linked with sodium alginate. And carrying out tape casting at 55-65 DEG C, and carrying out gradient drying at 40-50 DEG C, thereby obtaining the product. The film is compact and flexible, the breaking strength is larger than or equal to 69 MPa, the oxygen permeability is low, the inhibition zone on six germs is enlarged by 3-4 mm, 98% of natural soil is degraded 20 days later, and no toxic smoke is generated during incineration. The biodegradable film is solvent-free in preparation, can be produced by existing equipment, is lower than a traditional biodegradable film in cost, can be in direct contact with food, remarkably prolongs the fresh-keeping period of fruits and vegetables, replaces PE and PVC, and solves white pollution.

The invention belongs to the technical field of degradable and high-barrier modified plastics, and particularly relates to an environment-friendly, high-oxygen-barrier and water-resistant modified plastic, a plastic alloy and a functional product of the environment-friendly, high-oxygen-barrier and water-resistant modified plastic and the plastic alloy. According to the material, polyvinyl alcohol is used as a main component and is blended with auxiliaries such as a plasticizer and a cross-linking agent through a twin-screw melt extrusion technology, and modified plastic (HB-PVOH) with excellent barrier property, water resistance and mechanical property is formed. In order to further enhance the performance, the HB-PVOH can be co-extruded with polymers such as polyhydroxyalkanoate, polymethyl ethylene carbonate, polylactic acid, poly (butylene succinate) and the like to prepare binary or ternary plastic alloy. The material can be widely applied to the fields of high-end packaging, oxygen barrier coatings, environment-friendly packaging and the like, plastic or paper-plastic composite products are prepared through a multi-layer co-extrusion-film blowing, curtain coating or film spraying technology, the sustainable development trend of aluminum reduction, plastic reduction and fluorine reduction is met, and the material is a green packaging solution which is high in cost performance, environmentally friendly and practical.

The invention belongs to the technical field of medical wound materials, and relates to conductive nanofiber aerogel for preventing and treating stress injury and a preparation method thereof. The conductive nanofiber aerogel comprises nanofiber aerogel, a polypyrrole conductive network and a polydopamine hydrophilic layer, wherein the polypyrrole conductive network and the polydopamine hydrophilic layer are deposited in the nanofiber aerogel; the nanofiber aerogel is composed of nanofibers containing a first methylacryloylated polymer and polylactic acid and a second methylacryloylated polymer, the nanofibers are in staggered lap joint to form a three-dimensional skeleton, and the lap joint is wrapped by the second methylacryloylated polymer. The preparation method comprises the following steps: preparing nanofiber aerogel, and sequentially infiltrating the nanofiber aerogel into a pyrrole / FeCl3. 6H2O solution and a dopamine hydrochloride / Tris-HCl solution to react. The conductive nanofiber aerogel has good structural stability, biological safety, hydrophilic imbibition and pressure / seepage sensing capability, and can play an efficient role in prevention and treatment of pressure injury.

The invention relates to the technical field of food fresh-keeping materials, and discloses a preparation method of an intelligent response degradable fruit and vegetable fresh-keeping film based on a Janus structure, the intelligent response degradable fruit and vegetable fresh-keeping film comprises a hydrophobic layer and a hydrophilic layer, the hydrophobic layer is an electrostatic spinning film formed by compounding eugenol-loaded ZIF-8 nano-particles and polylactic acid, and the hydrophilic layer is an electrostatic spinning film formed by compounding eugenol-loaded ZIF-8 nano-particles and polylactic acid. The hydrophilic layer is an electrostatic spinning membrane formed by compounding chitosan and gelatin, the surface of the hydrophobic layer is covered with the hydrophilic layer through an electrostatic spinning technology, the ZIF-8 nanoparticles are synthesized through a room-temperature stirring method, and synthesis raw materials are a 2-methylimidazole methanol solution and a zinc nitrate methanol solution. By means of the pH response characteristic of the ZIF-8 nano-particles, pH value change signals generated in the early stage of fruit and vegetable putrefaction can be sensitively captured, loaded antibacterial components are accurately released through ZIF-8 framework dissociation, targeted inhibition on putrefying bacteria is achieved, passive protection is converted into active intervention, the fruit and vegetable putrefaction process is effectively delayed, the fresh-keeping effect is improved, and the fresh-keeping time is prolonged.

The application relates to a modified polylactic acid oligomer and a preparation method and application thereof. The modified polylactic acid oligomer has the structure shown in the following formula (I). The modified polylactic acid oligomer obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid has more excellent and stable and persistent antibacterial activity, the antibacterial efficiency is greatly improved, the sterilization rate is improved, and the sterilization time is shortened; when the modified polylactic acid oligomer is applied to various antibacterial coatings and textile finishing, the surface no longer has a wet sticky feeling, the commercialization and wide application of the material are more beneficial, and the modified polylactic acid oligomer has higher affinity to a target substrate, so that the persistence, stability and washability of a surface coating can be improved.

The invention relates to the field of sewage treatment, in particular to a method for recycling soybean protein wastewater resources. The soybean protein wastewater recycling method provided by the invention comprises the following steps: 1) mixing soybean protein wastewater, activated carbon and quaternary ammonium salt modified chitosan, stirring, standing and precipitating to obtain a precipitate turbid solution; 2) mixing the precipitate turbid liquid with a fermentation inoculant, carrying out anaerobic acidogenic fermentation, and carrying out centrifugal separation to obtain a carbon source stock solution; 3) heating and denitrifying the carbon source stock solution, mixing with sodium alginate, dissolving, and spray-drying to prepare a sodium alginate-carbon source microcapsule; and 4) preparing a degradable porous suspended filler from polylactic acid, filling the sodium alginate-carbon source microcapsule into pores of the degradable porous suspended filler, and sealing to obtain the slow-release carbon source suspended filler. The method provided by the invention can improve the current soybean protein wastewater utilization rate, reduce resource waste, and solve the problem of final direction of the soybean protein wastewater.