13667 results about "Ethylene glycol" patented technology

The invention discloses a method for preparing diester terephthalate by catalyzing polyethylene glycol terephthalate (PET) to depolymerize. The method comprises the following steps: treating PET or a composite system thereof in diester carbonate under the conditions of no catalyst or taking a salt substance as a catalyst to realize chemical depolymerization of PET, so as to obtain PET monomers of diester terephthalate and ethylene carbonate, and realize complete depolymerization of PET in a composite. According to the method disclosed by the invention, through the reaction of the diester carbonate and the PET, the depolymerization of the PET under a mild condition can be realized, and the related technology research and development of chemical recovery of the PET monomer in a PET composite system or a mixed system are further carried out. The method provided by the invention has the advantages of high efficiency, greenness, mild reaction conditions and the like, can catalyze PET depolymerization to generate the monomer terephthalic acid diester, and has higher industrial application value.

The invention belongs to the technical field of polyester recycling, and relates to a method for efficiently producing terephthalate by depolymerizing waste polyester through carbonic ester, which comprises the following steps: depolymerizing waste polyester, carbonic ester and a catalyst under the protection of nitrogen or inert gas and solvent-free conditions, a is more than one of zinc acetate, sodium acetate, potassium chloride, lithium chloride, potassium carbonate, sodium carbonate, ethylene glycol antimony, antimony trioxide, antimony acetate, ethylene glycol titanium and titanium dioxide, and B is sodium ethoxide. The method solves the problems of limited conversion of the waste polyester chemical recovery monomer and long production process in the prior art, obviously improves the catalytic efficiency and the depolymerization speed through the compound catalyst, simplifies the depolymerization process, reduces the energy consumption, and is beneficial to industrial application.

One aspect is a method for producing a first intermediate product. A feedstock is provided that comprises a first polyester. The feedstock is contacted with a first amount of a first organic compound in a volume section V1 to obtain a first initial mixture. The first amount is in the form of a liquid. The first polyester is transported, and at least a fraction of the first amount of the first organic compound, from the volume section V1 to a volume section V2. The volume section V2 is at least partially filled with the first organic compound. A level of the first organic compound in the volume section V1 is at a height H1 from a floor, and a level of the first organic compound in the volume section V2 is at a height H2 from the floor. The first polyester is contacted with a further organic compound in a volume section V3, to obtain a further initial mixture. A weight average molar mass of the first polyester is reduced in the volume section V3, to obtain a first intermediate mixture. The first intermediate mixture comprisesa first intermediate product,the further organic compound.H1<H2.

The invention belongs to the field of intelligent soft materials, and discloses conductive eutectic gel with self-adhesion, wide-temperature strain sensing and high sensitivity as well as a preparation method and application of the conductive eutectic gel. The eutectic gel is prepared from polydopamine, polyvinyl alcohol, a polymer monomer, a eutectic conductive agent (which is prepared by adding ethylene glycol and a conductive agent into a polyvinyl alcohol solution and stirring), a cross-linking agent, an initiator and water. Strain sensing related tests prove that the gel has excellent sensitivity and strain sensing performance, and has application potential in the fields of high and low temperature severe environment monitoring, human health monitoring and motion monitoring.

The invention discloses a multistage fire-fighting and intelligent heat management combined system and method for an energy storage system, a battery cluster is provided with a single fire extinguishing nozzle, a composite detector monitors the state of the battery cluster in real time, and when any battery cluster meets a spraying condition, the fire extinguishing nozzle is triggered to spray a fire extinguishing material; the internal state of the energy storage cabin is monitored in real time through a composite detector, and when the interior of the energy storage cabin meets the spraying condition, a spraying nozzle is automatically started to continuously spray for preset spraying time; according to the centralized liquid cooling unit, a dual-redundancy compressor is combined with an ethylene glycol aqueous solution circulating system to conduct dynamic flow regulation and control, the opening degree of an electromagnetic valve of the dual-redundancy compressor is dynamically adjusted through a composite detector, and the internal temperature of an energy storage cabin is controlled; dynamically distributing flow according to the energy storage time period by adopting an intelligent temperature control algorithm; after the multi-stage fire-fighting module acts, the centralized liquid cooling unit is started for cooling; when the temperature detected by the composite detector exceeds a high-temperature threshold value, the fan is started for air replacement, and the multi-stage fire-fighting module is triggered to act.

A process for chemically recycling waste polyethylene terephthalate (PET) carpet fibers. The process comprises providing a waste carpet fiber composition comprising at least 75 wt % of PET and 6 wt % or less of ash; reacting the waste carpet fiber composition with methanol to produce a depolymerized poly ester mixture comprising polyester oligomers, dimethyl terephthalate (DMT), and ethylene glycol (EG); and recovering the DMT and the EG from the depolymerized polyester mixture.

The invention relates to the field of functional master batch materials, in particular to a phase-change energy temperature-adjusting fiber master batch and a fat-burning fabric thereof. The phase-change energy temperature-regulating fiber master batch is prepared from a composite phase-change material and polyethylene glycol terephthalate slices through melt extrusion and granulation, the fat-burning fabric is prepared from the phase-change energy temperature-adjusting fiber master batch and polyethylene glycol terephthalate slices through melt spinning, network compounding and weaving processing. By introducing the microencapsulated phase-change material and the high-thermal-conductivity filler, in the melt extrusion process, the microencapsulated phase-change material and the high-thermal-conductivity filler can be uniformly dispersed in the matrix material to form stable fiber master batches, form an efficient thermal-conductivity structure and provide excellent thermal regulation performance; meanwhile, microencapsulation can improve the stability and dispersity of the phase-change material, and the fat-burning fabric is prepared through melt spinning and weaving of fiber master batches, so that the heat-conducting property of the product is improved, and the continuous fat-burning effect is achieved.

The invention relates to the technical field of chemical degradation of waste polyester, and discloses a titanium-silicon compound catalyst, a preparation method thereof and a method for depolymerizing polyethylene glycol terephthalate. The preparation method of the titanium-silicon compound catalyst comprises the following steps: (1) preparing a titanium compound, an orthosilicate compound and a solvent, and reacting with an organic acid solution to obtain a solution; and (2) carrying out post-treatment on the solution to obtain the titanium-silicon compound catalyst. The catalyst has the characteristics of high PET depolymerization rate, low polymerization degree in a depolymerization product, high purity of a depolymerization product bis (2-hydroxyethyl) terephthalate (BHET) and low titanium residue in a target product in a PET degradation reaction. The BHET obtained by the method disclosed by the invention can be directly used for preparing PET polyester products or other high-added-value products, and closed-loop cyclic utilization of PET is realized.

The invention relates to the technical field of polyester fibers, in particular to a high-strength wear-resistant polyester fiber and a preparation method thereof. The invention aims to solve the problem that the mechanical strength and wear resistance of the existing polyester fiber are difficult to consider at the same time. The preparation method comprises the following steps: carrying out esterification and polycondensation on terephthalic acid, ethylene glycol, hydroxyl-terminated polydimethylsiloxane and isophthalic acid to obtain modified PET; the preparation method comprises the following steps: respectively carrying out oxidation treatment on graphene and a multi-walled carbon nanotube, and then adding polyether amine for grafting; carrying out melt blending with PET slices to obtain nano master batches; carrying out melt blending on the chopped glass fibers and the PET slices to prepare micron master batches; and mixing the modified PET, the nano master batch and the micron master batch, carrying out ultrasonic dispersion, adding an auxiliary agent, and carrying out melt spinning, three-section stretching and three-section heat setting treatment to obtain the high-strength wear-resistant polyester fiber. Through the synergistic effect of the components and the process, the prepared fiber has excellent mechanical properties and wear resistance, and has wide application prospects in the fields of clothing, home textiles, industry and the like.

The invention relates to the field of textile materials, and provides an antibacterial breathable yarn obtained by blended spinning of polyester fibers, polyamide fibers, cotton fibers and elastic fibers. The polyester fiber is prepared through melt blending and spinning processes and comprises polyethylene glycol terephthalate slices, modified chitosan zinc oxide, an antioxidant 1010, a POE elastomer, polyether modified silicone oil and polyethylene glycol 200, and the modified chitosan zinc oxide is prepared by compounding chitosan cinnamyl aldehyde Schiff base and silane modified zinc oxide. The chitosan cinnamyl aldehyde Schiff base is prepared through a Schiff base condensation reaction of chitosan and cinnamyl aldehyde, and the silane modified zinc oxide is prepared from nano rod-shaped zinc oxide particles modified by isocyanate propyl triethoxy silane. The yarn has excellent antibacterial property, air permeability and flexibility and is further used for knitting antibacterial breathable socks, the knitting density of the sock bottom part is reduced to enhance the air permeability, the knitting density of the sock opening part is improved to improve the elasticity and the fitting degree, and the yarn has wide application value.

The invention relates to a preparation method and application of a composite porous carbon-based negative electrode material with soft carbon coated with hard carbon. The preparation method comprises the following steps: (S1) carbonizing and activating a soft carbon material precursor to obtain soft carbon core particles; (S2) carrying out graft modification on the oxidized soft carbon inner core particles through dopamine polyethylene glycol silane, and then carrying out in-situ copolymerization reaction on the modified soft carbon inner core particles and dopamine to obtain organic silicon-polydopamine coated soft carbon composite particles; (S3) carrying out in-situ polymerization of phenolic aldehyde on the surfaces of the composite particles to form phenolic aldehyde coated soft carbon composite particles; (S4) carbonizing and activating the phenolic aldehyde coated soft carbon composite particles to obtain hard carbon coated soft carbon composite porous carbon; and (S5) carrying out silicon deposition and carbon coating on the composite porous carbon to obtain the composite porous carbon-based negative electrode material with soft carbon coated with hard carbon. When the composite porous carbon-based negative electrode material with the soft carbon coated with the hard carbon prepared by the invention is applied to a negative electrode of a lithium battery, the composite porous carbon-based negative electrode material has good electrochemical performance, and particularly has excellent cycle performance and compression resistance.

The invention discloses an alkaline battery capable of improving low-temperature discharge performance and a preparation method thereof, and the preparation method comprises the following steps: S1, preparing a positive electrode ring: preparing a positive electrode material from metal-doped composite manganese dioxide, an adhesive and a potassium hydroxide solution; s2, preparing negative electrode zinc paste, mixing and ball-milling nano zinc powder, indium powder and gallium powder into alloyed zinc powder, adding a composite conductive additive, a composite binder and a low-temperature-resistant additive, and stirring and dispersing to form the negative electrode zinc paste; s3, sleeving the positive electrode ring into the steel shell, inserting a diaphragm and injecting electrolyte; and S4, injecting negative electrode zinc paste, and packaging to obtain a finished product. According to the negative electrode zinc paste, the zinc utilization rate can be increased through nano zinc powder alloying, meanwhile, the freezing point is reduced through the low-temperature-resistant additive, and the reaction efficiency and fluidity of the negative electrode zinc paste at the low temperature are improved; ethylene glycol in the electrolyte is combined with nano zirconium dioxide, so that the stability and the ion migration capability can be improved, the discharge performance of the alkaline battery under a low-temperature working condition is improved, and the service life of the alkaline battery under the low-temperature working condition is prolonged.

The invention relates to the technical field of fibers, and discloses an ultrahigh-moisture-absorption anti-static polyester fiber and a preparation method thereof. The preparation method comprises the following steps: carrying out nucleophilic substitution reaction on 1, 2-benzisothiazolin-3-one and methacryloyl chloride to obtain modified benzisothiazolinone; the preparation method comprises the following steps: carrying out nucleophilic substitution reaction on phosphonitrilic chloride trimer and allylamine, and then carrying out nucleophilic substitution reaction on the phosphonitrilic chloride trimer and melamine again to obtain modified cyclophosphazene; the preparation method comprises the following steps: mixing gamma-methacryloxypropyltrimethoxysilane with aluminum zinc oxide for reaction, and mixing the obtained modified aluminum zinc oxide with modified benzisothiazolinone and modified cyclophosphazene for copolymerization in the presence of an initiator to obtain a flame-retardant antibacterial additive; mixing the flame-retardant antibacterial additive, calcium carbonate and polyethylene glycol terephthalate, performing melt spinning, and performing acid treatment to obtain modified polyester fibers; dipping the modified polyester fiber in a finishing liquid containing modified chitosan to obtain the ultrahigh-moisture-absorption anti-static polyester fiber.

The invention relates to the technical field of textiles, in particular to a wear-resistant antibacterial flax blended yarn and a preparation process thereof. The method specifically comprises the following steps: S1, after performing ultraviolet irradiation on cotton fibers, putting the cotton fibers into a wear-resistant antibacterial solution, and performing dipping and drying to obtain wear-resistant fibers; s2: (1) modifying chitosan by using 6-maleimidohexanoic acid, so as to obtain modified chitosan; (2) sequentially reacting polyethylene glycol adipate with isophorone diisocyanate, modified chitosan and sodium 2-mercaptoethanesulfonate, and finally emulsifying to obtain a fiber treating agent; s3, (1) performing opening mixing, cotton carding, drawing, roving, spinning and spooling on the linen fibers and the wear-resistant fibers in sequence to obtain a linen blended yarn crude product; and (2) soaking the flax blended yarn crude product into the fiber treating agent, padding and drying to obtain the wear-resistant antibacterial flax blended yarn.

The invention relates to the technical field of degradable plastics, and provides biodegradable plastic particles as well as a preparation method and application thereof. The biodegradable plastic particles comprise the following components in parts by weight: 50-80 parts of PLA, 20-50 parts of PBAT, 5-20 parts of a filler, 1-8 parts of a flexibilizer, 1-5 parts of a lubricant and 5-10 parts of a modifier. The modifier comprises a polylactic acid-polyethylene glycol block copolymer and a polycaprolactone-polyglycidyl methacrylate block copolymer in a mass ratio of (1: 19)-(19: 1). According to the technical scheme, the problems of poor flexibility and strength of plastic particles in related technologies are solved.

The invention relates to the technical field of environmental materials and water treatment, in particular to a graphene amino silica gel composite adsorbent for heavy metal wastewater treatment and a preparation method thereof.The graphene amino silica gel composite adsorbent is prepared from # imgabs0 nanoparticles, an amino-functionalized silicon dioxide coating layer, carboxylated reduced graphene oxide, a polydopamine modification layer and tetraethyl orthosilicate; the coating is prepared from the following raw materials: 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, N-((4-vinyl benzyl) amino) diacetic acid, chitosan, beta-cyclodextrin, hexadecyl trimethyl ammonium bromide, polyethylene glycol, L-ascorbic acid, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide. The composite adsorbent shows excellent adsorption performance on various heavy metal ions, and the adsorption performance is far higher than that of traditional adsorption materials and existing composite adsorbents.

The invention discloses a cosmetic composition and a preparation method thereof, and belongs to the technical field of cosmetics. The invention discloses a chamomile essential oil toner which is mainly prepared from the following raw material components in parts by mass: 10 to 20 parts of modified toner, 50 to 60 parts of water, 4 to 6 parts of glycerol, 2 to 4 parts of propylene glycol, 0.8 to 1.2 parts of sodium chloride, 6.5625 to 7.875 parts of chamomile essential oil polymer micelle, 2.1875 to 2.625 parts of adhesive, 10.5 to 11.5 parts of capric triglyceride and 0.8 to 1.2 parts of cetyl polyethylene glycol. Through the synergistic effect of the modified toner and chamomile essential oil polymer micelles in a specific ratio, the dispersion stability of the toner is improved, meanwhile, the slow release effect of active ingredients is enhanced, and the chamomile essential oil toner has the advantages that the makeup holding property, the storage stability and the mildness are improved, meanwhile, the toner dispersity is improved, and the sensitive skin stimulation risk is reduced.

The invention discloses a high-toughness polyester heat shrinkage film not prone to brittle fracture and a preparation method thereof, and belongs to the technical field of polymer packaging materials. A specific formula of the polyester heat shrinkage film consists of pure polyethylene glycol terephthalate, dihydric alcohol modified polyethylene glycol terephthalate, polybutylene terephthalate, a toughening-crystallization nucleating complexing agent, a crystallization accelerant, an opening slipping agent and filler. According to the polyester heat shrinkage film obtained by the invention, the thickness is 31.1-51.6 microns, the tensile strength is TD193-202 MPa, the tensile strength is MD23-85 MPa, the elongation at break is TD26-52%, the elongation at break is MD52-46%, the shrinkage rate TD is 47-80%, the shrinkage rate is MD0-15%, the haze is 4.2-5.0%, the light transmittance is 86.5-87.4%, and the elongation at break is not greatly reduced after the polyester heat shrinkage film is placed in a normal-temperature and normal-humidity environment for 24 months and placed in a high-temperature and high-humidity environment for 18 days.

The invention discloses a uniform carbon-coated lithium iron phosphate positive electrode material and a preparation method thereof, and relates to the technical field of lithium iron phosphate positive electrode materials, the uniform carbon-coated lithium iron phosphate positive electrode material comprises lithium iron phosphate matrix particles, the lithium iron phosphate matrix particles are coated with a composite carbon layer, and the composite carbon layer is doped with cerium modified tantalum carbide nanocrystals; the preparation method of the cerium modified tantalum carbide nanocrystal comprises the following steps: dissolving pentaethoxy tantalum and cerous nitrate in ethylene glycol, adding urea as a precipitator, and synthesizing a Ta-Ce-O precursor through a microwave-assisted solvothermal method; the Ta-Ce-O precursor and phenolic resin are mixed and then subjected to ball milling and sintering, and the cerium modified tantalum carbide nanocrystal is obtained. By introducing a small amount of cerium modified tantalum carbide nanocrystals into the composite carbon layer for many times, uniform coating of the composite carbon layer can be realized, and the electrochemical performance of the lithium iron phosphate positive electrode material is enhanced.

The invention belongs to the technical field of polymer heat conduction, and particularly relates to a preparation method of a high-heat-conductivity polymer with modified boron nitride as filler, which comprises the following steps: (1) dissolving boron nitride nanosheets into tetrahydrofuran, ultrasonically dispersing uniformly, adding a modifier for reaction, then removing tetrahydrofuran by using a rotary evaporator, transferring into deionized water, and drying to obtain a boron nitride nano-sheet; drying to obtain a modified boron nitride nanosheet; (2) dispersing carbon nanotubes in deionized water, stirring and carrying out ultrasonic treatment, adding the modified boron nitride nanosheets, and then carrying out freeze orientation treatment and freeze drying treatment to obtain a porous foamed composite heat-conducting filler; and (3) carrying out melt blending on the composite heat-conducting filler and polyethylene glycol terephthalate, and carrying out hot press molding to finally prepare the modified high-heat-conductivity polymer. According to the invention, the composite heat-conducting filler improves the interfacial compatibility and dispersity with a polymer matrix, and reduces the interfacial thermal resistance of the composite material, so that the modified polymer has good application in the aspect of heat dissipation of electronic equipment.

The invention relates to a method for purifying a monomer bis (2-hydroxyethyl) terephthalate (BHET) obtained by depolymerizing waste polyester through ethylene glycol (EG), and belongs to the technical field of polyester recycling. The BHET microwave radiation induced film evaporation separation and molecular distillation refining continuous process provided by the invention solves the problems of long process flow, poor continuity, more side reactions and low purity and yield in the direct separation and refining process of BHET in alcoholysis liquid based on a gas-liquid equilibrium separation method at present. The whole technological parameter requirement is mild, the process is short, continuity is good, the BHET purity of the product is larger than or equal to 99.0 wt%, the hue is good, and the BHET yield is larger than or equal to 80.0%. And meanwhile, the method has the advantages that EG is conveniently recycled in a system, the production process is cleaner and more environment-friendly, and the comprehensive efficiency advantage is obvious.

The invention discloses a bamboo powder-containing biodegradable plastic for food contact and a preparation method thereof, and relates to the technical field of bio-based materials. The bamboo powder-containing biodegradable plastic for food contact comprises chitosan starch and modified bamboo powder, the chitosan starch is prepared by adding composite chitosan and amino-terminated polyethylene glycol into oxidized corn starch, and the composite chitosan is prepared by grafting chlorogenic acid on the surface of chitosan and then coating succinic anhydride derivatives. The succinic anhydride derivative is prepared from dodecenyl succinic anhydride and 1, 4-butanediamine through a reaction, so that the plastic has the antibacterial property, and meanwhile, the mechanical property is enhanced; the modified bamboo powder is prepared by reacting bamboo powder with a carboxyl-terminated composition, and the carboxyl-terminated composition comprises carboxyl-terminated polylactic acid and carboxyl-terminated polyamide. The toughness of the plastic is enhanced, and the mechanical property of the plastic is further enhanced.

The invention relates to the technical field of high-performance polyester, in particular to a high-strength low-shrinkage polyester fiber and a preparation method thereof. The defects that existing polyester fibers are poor in strength and shrinkage resistance are overcome. The preparation method comprises the following steps: mixing the modified resin, the modified nano silicon dioxide, the composite antioxidant, the composite nucleating agent and the composite lubricant, and carrying out melt spinning. Wherein the modified resin is prepared from the following raw materials: dimethyl terephthalate, isophthalic acid, ethylene glycol and isosorbide; the modified nano silicon dioxide comprises nano silicon dioxide, KH570 and silver nitrate; the composite antioxidant comprises an antioxidant 1010, an antioxidant 168 and an antioxidant 1222; the composite nucleating agent comprises sodium benzoate and nano montmorillonite; the composite lubricant is prepared from ethylene bis stearamide and pentaerythritol stearate. The prepared polyester fiber is high in strength, high in shrinkage resistance and suitable for manufacturing of outdoor equipment.

The invention discloses photocuring hydrogel capable of being combined with cytokines and used for tumor organoid culture and application, and belongs to the technical field of organoid culture. According to the invention, the hydrogel which can fix cells, can be combined with cell factors and can realize organoid recovery is developed through norbornene modified heparin, norbornene modified gelatin, sulfydryl four-arm polyethylene glycol, glucan, matrix metal protein peptidomimetic MMP and a photoinitiator. The hydrogel can be used for directly preparing organoids, heparin of various structures can be used, the cost is reduced, the modified heparin can bind factors or matrix protein and can controllably release the factors, the modified gelatin provides amino acid energy for collagen hydrolysate, and the hydrogel is formed by photocuring in a stepwise polymerization mode, is controllable in structure and can be used for preparing collagen collagen. The adjustable bionic modulus and the adjustable bionic stress relaxation are realized. The hydrogel disclosed by the invention can be used for culturing various organs, overcomes the problems of low repeatability, instability and the like in the prior art, and is suitable for the fields of tumor drug evaluation and the like.

The invention relates to the technical field of all-solid-state lithium metal batteries, in particular to a cellulose paper-based polymer solid electrolyte as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing N-methylacetamide and lithium bis (trifluoromethanesulfonyl) imide to obtain a eutectic solvent; the preparation method comprises the following steps: mixing a eutectic solvent, polyethylene glycol oxalate, acrylamide and a thermal initiator to obtain a eutectic polymer electrolyte precursor; and soaking cellulose paper in the eutectic polymer electrolyte precursor, and carrying out hot-pressing polymerization to obtain the cellulose paper-based polymer solid electrolyte. The cellulose paper-based polymer solid electrolyte prepared by the invention is soft in texture and can be better attached to an electrode, the problem of poor contact between the electrode and an electrolyte interface is solved, and the interface impedance is reduced by fusing the characteristics of low viscosity and high conductivity of the eutectic solvent and the supporting effect of the cellulose paper; the ion transmission efficiency is improved, and conditions are provided for long-term stable circulation of the battery.

The invention discloses thermosetting unsaturated polyester resin as well as a preparation method and application thereof, and belongs to the technical field of unsaturated polyester resin. The raw materials comprise the following components in parts by weight: 270 to 380 parts of neopentyl glycol, 90 to 150 parts of ethylene glycol, 400 to 570 parts of isophthalic acid, 0.4 to 1.0 part of an antioxidant, 0.3 to 0.8 part of a catalyst, 80 to 170 parts of propylene glycol, 260 to 380 parts of maleic anhydride, 0.03 to 0.09 part of a first polymerization inhibitor, 0.1 to 0.3 part of a second polymerization inhibitor, 0.1 to 0.4 part of a third polymerization inhibitor and 800 to 900 parts of styrene. The thermosetting unsaturated polyester resin disclosed by the invention has relatively high mechanical properties and corrosion resistance after being cured, still can keep relatively high mechanical properties after being corroded by acid and alkali, is high in bending deformation resistance, and can be applied to thermosetting trenchless repair of buildings or pipelines.

The invention discloses a dual-curing 3D printing resin, the dual-curing 3D printing resin comprises an acrylate oligomer containing a dynamic covalent bond and a blocked isocyanate cross-linking agent, and the acrylate oligomer containing the dynamic covalent bond is obtained by reacting an isocyanate-terminated oligomer with acetoacetic acid ethylene glycol methacrylate. The internal molecular structure and the crosslinking density of the dual-curing 3D printing resin can be changed through heat treatment after light curing, and the dual-curing 3D printing resin has excellent stability and can be stored and used in a single-component mode.

The invention discloses preparation and application of a block cationic copolymer / quaternary ammonium salt chitosan-based composite hydrogel. The preparation method comprises the following steps: reacting a sodium alginate solution with a NaIO4 solution at room temperature in a dark place to obtain an oxidized sodium alginate solution; adding ethylene glycol into the oxidized sodium alginate solution, reacting, concentrating, dialyzing and drying to obtain oxidized sodium alginate; the preparation method comprises the following steps: mixing acrylamide, 1-butyl-3-vinyl imidazole ammonium bromide, 3-acrylamide phenylboronic acid and quaternary ammonium salt chitosan, dissolving in water, adding ammonium persulfate and N, N-methylene bisacrylamide, heating for reaction, and cooling to obtain a cooling liquid; adding the oxidized sodium alginate solution into the cooling liquid, continuously adding polymerized N, N, N ', N'-tetramethylethylenediamine, reacting and curing to obtain composite hydrogel; and soaking the composite hydrogel in a glycerin / water mixed solution to obtain the composite hydrogel. When the composite hydrogel is used as a wound dressing, the composite hydrogel has the characteristics of good antibacterial activity, high sterilization efficiency, good anti-freezing and anti-drying performance and difficulty in generating drug resistance.

The invention relates to the technical field of biological extraction, in particular to a green synergistic extraction system and an extraction method and application thereof.The green synergistic extraction system comprises a deep eutectic solvent system, an enzymolysis system and an ultrasonic-assisted extraction system, and the deep eutectic solvent system comprises a DES solvent; the DES solvent is composed of a hydrogen bond acceptor and a hydrogen bond donor, and the hydrogen bond acceptor is choline, choline chloride or L-proline; the hydrogen bond donor is lactic acid, urea or ethylene glycol; enzyme preparations in the enzymolysis system are at least two of cellulase, pectinase and beta-glucosidase; the problems that a traditional organic solvent is high in toxicity and poor in biodegradability and synthetic deep eutectic solvent raw materials are non-renewable are solved, a green synergistic extraction system which is environmentally friendly, low in cost and excellent in performance is developed, the mass transfer efficiency and the extraction yield are improved, the used DES and enzyme preparations can be recycled, and the cost is reduced while the environment is protected.

The invention relates to the technical field of chemical degradation of waste polyester, and discloses a titanium-rare earth compound catalyst which comprises a titanium-containing compound and a rare earth catalyst, wherein the titanium-containing compound is selected from at least one of dihydric alcohol modified alkyl titanate, alkyl titanate, dihydric alcohol titanium, titanium phosphate and organic-inorganic hybrid titanium; wherein the rare earth catalyst is selected from acetylacetone rare earth catalysts. The titanium-rare earth compound catalyst has the characteristics of high PET depolymerization rate, low polymerization degree in a depolymerization product, small catalyst dosage, high catalyst selectivity and high yield and purity of a depolymerization product bis (2-hydroxyethyl) terephthalate (BHET) in a degradation reaction of polyethylene glycol terephthalate (PET). The BHET obtained by the method disclosed by the invention can be directly used for preparing PET polyester products or other high-added-value products, and closed-loop cyclic utilization of PET is realized.