92 results about "Ethyleneglycol bis" patented technology

The invention relates to a bionic exosome for anti-inflammation and repair as well as a preparation method and application thereof, and belongs to the field of cosmetics. The bionic exosome provided by the invention comprises a membrane structure and an internal load phase, the membrane structure comprises a phospholipid bilayer, a stabilizer and a targeting ligand; the internal load phase comprises a solvent and an active component; the phospholipid bilayer is composed of phospholipid compounds; preferably, at least one of the distearoyl phosphatidyl ethanolamine-polyethylene glycol 2000 and the 1, 2-dioleoyl-sn-glycerol-3-phosphoethanolamine is adopted as the phospholipid compound, and at least one of the distearoyl phosphatidyl ethanolamine-polyethylene glycol 2000 and the 1, 2-dioleoyl-sn-glycerol-3-phosphoethanolamine is adopted as the phospholipid compound; at least one of cholesterol, phytosphingosine and sodium stearoyl glutamate is preferably adopted as a stabilizer, so that the stabilizer of the obtained bionic exosome is improved, and the bionic exosome has the advantages of high encapsulation efficiency, good encapsulation efficiency stability, simplicity in operation, excellent anti-inflammatory and repairing effects and the like.

The invention relates to the technical field of ethylene glycol diacetate preparation, and discloses ethylene glycol diacetate preparation reaction equipment, which comprises a tower body, a reboiler and a condenser, the top of the tower body is connected with the condenser, the bottom of the tower body is connected with the reboiler, a tower plate is installed in the tower body, the tower plate is driven to rotate in the tower body, and the tower plate has a first state and a second state, in the first state, the tower plate is of an L-shaped structure and is horizontally arranged, and in the second state, the tower plate is of a linear structure and is inclined downwards; the tower plate provided by the invention can be kept in the second state in the cleaning process, and when water flows on the tower plate in the second state, the tower plate is of a linear structure, so that the tower plate in the state does not influence impact force generated by flowing of the water, and the tower plate can be smoothly flushed.

The present disclosure describes a razor cartridge including a housing having a front edge and a rear edge; shaving blades disposed between the front edge and the rear edge; and at least one shaving bar disposed in front of the blade(s) and / or rear of the blade(s) which includes a solid shaving aid composition that includes, relative to the total weight of the solid shaving aid composition: about 15 wt.-% to about 48 wt.-% of a soap base including of one or more fatty acid salts having from about 8 to about 24 carbon atoms and optionally one or more fatty acids having from about 8 to about 24 carbon atoms, at least about 35 wt.-% of one or more polyols including from ˜2 to ˜8 carbon atoms; the polyol selected from a group including glycerol, sorbitol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, methylpropane diol glycol.

The invention discloses a self-crystallization type amino acid cleansing cream composition and a preparation method thereof. Comprising the following components in percentage by weight: 20%-40% of glycerol, 15%-25% of cocoyl glycinate, 1%-10% of cocoyl hydrolyzed collagen potassium, 0.1%-5% of sodium lauroamphoacetate, 0.1%-3% of citric acid, 0.1%-3% of sodium methyl cocoyl taurate, 0.1%-3% of sodium chloride, 0.1%-3% of sodium lauroyl glutamate, 0.1%-3% of ethyoxyl diethylene glycol, 0.1%-3% of propylene glycol laurate, 0.1%-3% of PEG-150 stearate, 0.1%-3% of ethylene glycol distearate, 0.0%-2% of 1, 3-propylene glycol distearate, 0.0%-2% of 1, 3-propylene glycol distearate and the balance of water. The cleaning agent is prepared from the following components in percentage by weight: 0.0 to 2 percent of 1, 2-hexanediol, 0.0 to 2 percent of p-hydroxyacetophenone and The self-crystallization type cleansing cream composition disclosed by the invention is high in crystallization point, good in thermal stability, mild and low in irritation, and has the effects of moisturizing and promoting cell proliferation, and the overall performance is improved.

This invention belongs to the field of two-dimensional material preparation technology, and provides an MXene material and its preparation method. The preparation method of the MXene material includes: mixing a MAX phase precursor to be etched with an organic halide reagent and a morphology modifier, performing a solvothermal etching reaction, and after the reaction, washing and drying the resulting product to obtain the MXene material; wherein the organic halide reagent is triethylamine trihydrofluoride, triethylamine hydrochloride, or dichloroethylamine hydrochloride, and the morphology modifier is ethylene glycol, dimethyl sulfoxide, or cyclohexane. The method of this invention can effectively control the microstructure and pore structure of the MXene material.

A polyelectrolyte hydrogel coating with strong substrate binding performance and a method of manufacturing the same are provided. The method includes: 1) activating a substrate by applying oxygen plasma; and 2) dissolving a polycationic polymer, a polymeric monomer, a silane coupling agent and an initiator to obtain a precursor solution, vacuumizing the precursor solution to remove air bubbles, applying the vacuumized precursor solution to a surface of the substrate activated by the oxygen plasma, and performing an in-situ polymerization and curing process under nitrogen or rare gas atmosphere. The polymeric monomer includes at least one of: acrylamide, acrylic acid, hydroxyethyl methacrylamide, 2-acrylamido-2-methyl-1-propanesulfonic acid, polyethylene glycol (diol) diacrylate, 2-methacryloxyethylphosphocholine, 3-[[2-(Methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonate, and 3-[[2-(methacryloyloxy)ethyl]dimethylammonium] propionate. The silane coupling agent has a carbon-carbon double bond functional group.

In order to overcome the problems of high recovery price, high energy consumption and low utilization rate of the existing kettle residue for the production of ethylene glycol by ethylene carbonate alcoholysis method, the application provides a kettle residue recovery method and device for the production of ethylene glycol by ethylene carbonate alcoholysis method, and the application provides a kettle residue recovery method for the production of ethylene glycol by ethylene carbonate, which comprises the following steps: under the conditions of temperature 150-250 DEG C and pressure 0.6-2 MPa, the ethylene glycol in the kettle residue produced by the preparation of ethylene glycol by ethylene carbonate alcoholysis method is converted into diethylene glycol under the catalysis of alkali metal salt catalyst, and after the reaction is completed, the kettle residue is a mixture of ethylene glycol, diethylene glycol, triethylene glycol and salt, the mixture is purified, and ethylene glycol and diethylene glycol are recovered; the economic benefit is improved, the rectification separation operation is simplified, the equipment investment and the overall energy consumption are reduced, and the utilization rate of ethylene glycol kettle residue is improved.

The invention discloses a temperature-sensitive slow-release medical auxiliary material and a preparation method of the temperature-sensitive slow-release medical auxiliary material, and belongs to the technical field of medical auxiliary materials. Comprising the following components: 1-2% w / v of acrylamide hydroxyethyl chitosan, 5-15% w / v of polyethylene glycol diacrylate, 1-6% w / v of N-methyl acrylate caprolactam, 0.05-2% w / v of an initiator, 0.01-0.5% w / v of a cross-linking agent and the balance of a PBS (Phosphate Buffer Solution), the acrylamide hydroxyethyl chitosan is modified by chitosan hydroxyl group and ethyl group; the N-methyl acrylate caprolactam monomer provided by the invention effectively improves the temperature sensitivity of the temperature-sensitive polymer auxiliary material; the acrylamide hydroxyethyl chitosan can reduce the swelling ratio and slow down the drug release; the polyethylene glycol diacrylate can be a crosslinking monomer of the temperature-sensitive polymer auxiliary material, meanwhile, an ether bond is introduced to improve the biocompatibility of the temperature-sensitive polymer auxiliary material, and the temperature-sensitive slow-release medical auxiliary material which is low in drug slow-release rate and responds to the temperature of a human body is prepared by combining the polyethylene glycol diacrylate, the ether bond and the temperature-sensitive polymer auxiliary material.

The present invention provides a method and a device for recovering ethylene in ethylene gas containing seal oil, relating to the technical field of ethylene recovery. In the present invention, ethylene glycol diacetate is used as a solvent to absorb ethylene in the ethylene gas containing seal oil, and the obtained ethylene-rich liquid is analyzed, so as to realize the efficient separation and recovery of ethylene. The recovery rate of ethylene is high, and the recovered ethylene can be directly used in the production of vinyl acetate by the ethylene method, greatly reducing the consumption of ethylene raw materials in the process of producing vinyl acetate by the ethylene method. Moreover, ethylene glycol diacetate is produced as a by-product in the process of producing vinyl acetate by the ethylene method. In the present invention, ethylene glycol diacetate (EGDA) is used as a solvent, and no new impurities are introduced.

The invention belongs to the technical field of precious metal extraction, and particularly relates to a synergistic extraction separation method for gold in a high-concentration gold-containing solution, diethylene glycol dibutyl ether, tributyl phosphate and sulfonated kerosene are mixed to obtain a synergistic extraction agent, and the synergistic extraction agent is used for extracting a gold-containing chlorination leaching solution to obtain a gold-containing extraction phase; in the synergistic extractant, the molar ratio of diethylene glycol dibutyl ether to tributyl phosphate is (5-35): 1; in the synergistic extraction agent, the concentration of diethylene glycol dibutyl ether is 0.5 to 3.5 mol / L; according to the method provided by the invention, the extraction agent is selected, and the extraction process parameters such as the ratio of the extraction agent, the ratio of an organic phase to water, the extraction temperature and the extraction stage number are adjusted, so that a good extraction and separation effect on gold can be obtained, and efficient separation of gold in the high-concentration gold-containing solution is realized. The method is good in synergistic effect, good in gold and impurity separation effect and high in efficiency.

The invention discloses a keloid treatment gel material capable of reducing lactic acid generation, and belongs to the technical field of keloid treatment. The material is prepared by the following steps: firstly, carrying out esterification on 9-oxabicyclo [3.3. 1] nonane-2, 6-diol and S-allyl-L-cysteine to obtain an intermediate A, and then carrying out Schiff base reaction on the intermediate A and 5-methoxy heliotropin to obtain an intermediate B containing double bonds; then, copolymerizing with methylacryloylated chitosan and polyethylene glycol diacrylate under photo-initiation to form a cross-linked network structure; finally, active ingredients such as quercetin-3-O-glucuronide and luteolin-3 '-glucuronide are included, and auxiliary materials such as a humectant and a preservative are added, so that the composition is prepared. The gel has a slow release function, can effectively inhibit glycolysis, reduce lactic acid generation, scavenge free radicals and regulate inflammation and fibrosis microenvironment, has good biocompatibility and oxidation response drug release characteristics, and is suitable for prevention and treatment of keloids.

The present invention discloses a concrete brightener and a preparation method thereof, comprising the following components by weight: 100-140 parts of a hydrophilic unsaturated carboxylic acid ester, 70-100 parts of a lipophilic unsaturated carboxylic acid ester, 0.5-2 parts of a modified single-walled carbon nanotube, 8-14 parts of ethylene glycol distearate, 5-9 parts of an imidazoline compound, 2-7 parts of a polyglycerol fatty acid ester, 6-12 parts of a nonionic surfactant, 18-35 parts of a fluorocarbon surfactant, 5-9 parts of a molecular regulator, 3-8 parts of an initiator, and 664-783 parts of water. The present invention can be used in conjunction with an admixture during concrete prefabrication. After use, the concrete brightener has a smooth surface and more uniform color of cement products, can maintain a long-lasting brightening effect, and can achieve strong adsorption and dispersion effects on cement, thereby improving the strength and surface hardness of cement products and enhancing the surface brightness, smoothness, and wear resistance of cement products. Furthermore, the present invention has mild preparation conditions and does not use any organic solvents during the synthesis process, making it safe and environmentally friendly.

The invention belongs to the technical field of artificial leather, and particularly relates to an essence mixture, fragrant PVC (polyvinyl chloride) leather and a preparation method thereof. The essence premix is added into the formula for modification, so that the prepared artificial leather can release fragrance for a long time. The essence premix comprises essence methyl dihydrojasmonate and tridecanedioic acid cyclic ethylene glycol diester, and the mass ratio of the methyl dihydrojasmonate to the tridecanedioic acid cyclic ethylene glycol diester is 1: (1-4). A small amount of essence is added in the formula, the fragrance emitted by the essence can effectively shield the smell of the raw materials, special equipment is not needed for production, special treatment is not needed, and the product cost can be effectively reduced; the fragrant PVC leather prepared by the invention can effectively control the volatilization amount and the volatilization speed of the fragrance of the essence. The fragrance duration is effectively prolonged, and the effect of slowly releasing fragrance for a long time is achieved.

The present application relates to the technical field of pesticide preparation, in particular to a microemulsion containing fluroxypyr-isooctyl and aminoclopidol and a preparation method thereof, which is composed of the following components in percentage by mass: fluroxypyr-isooctyl 1-15%, aminoclopidol 1-15%, composite emulsifier 10-22%, co-emulsifier 5-11%, composite solvent 15-28%, antifreezing agent 2-6%, stabilizer 0.5-2.5%, and deionized water, with the total being 100%. The composite emulsifier is composed of dioctyl sodium sulfosuccinate and triphenyl ethenyl phenol polyoxyethylene ether phosphate triethanolamine salt, the composite solvent is composed of N,N-dimethyl decanamide and ethylene glycol diacetate, the stabilizer is composed of epoxidized soybean oil and citric acid, the co-emulsifier is dipropylene glycol methyl ether, and the antifreezing agent is glycerol. The microemulsion containing fluroxypyr-isooctyl and aminoclopidol and the preparation method thereof effectively solve a plurality of technical problems in the compounding process of the two active ingredients and have significant technical advantages.

The invention belongs to the field of external medicines for pets, and provides a macromolecular medicine carrier for treating cat tinea, which is prepared by adopting a collaborative design of core-shell nanogel particles and a double-state antibacterial component and through stepwise reaction of hexamethylene diisocyanate, polyethylene glycol, polyethylene glycol diamine and a silane coupling agent. A core-shell structure with the particle size of 100-350 nm and the shell thickness of 5-30 nm is formed through water dispersion emulsification and silane hydrolytic condensation, and a Si-O-Si bond fixed state and non-covalent releasable state antibacterial mechanism is constructed by combining polyhexamethylene biguanide hydrochloride. According to the invention, the powerful antibacterial property of the minimal inhibitory concentration of 0.2-3.00 mg / mL to pathogenic dermatophyte is realized, a low-viscosity processing window and skin-friendly pH value are kept at 5.5-7.5, the coupling problem of high load, long-acting washing resistance, rapid effect and continuous inhibition and film-forming adhesion durability of an external preparation is solved, and the preparation has wide application value.

The invention provides a preparation method of ethylene sulfate in order to solve the problems that in the prior art, ethylene glycol, thionyl chloride, sodium hypochlorite and ruthenium trichloride are used for preparing ethylene sulfate, cost is high, operation is complex, generated waste brine has adverse effects on the environment, and sodium ions and chloride ions in ethylene sulfate easily exceed standards. Comprising the following steps: mixing and heating concentrated sulfuric acid and ethylene glycol to carry out esterification reaction, continuously bubbling and introducing sulfur trioxide gas into a mixed solution composed of the concentrated sulfuric acid and the ethylene glycol in the esterification reaction process, and after the esterification reaction is finished, carrying out post-treatment to obtain the ethylene sulfate. According to the preparation method of the ethylene sulfate provided by the invention, the cost is low on the basis of obtaining higher yield, the technological process is simple to operate, the reaction conditions are milder, a dehydrating agent is not needed, sulfur trioxide can be recycled, three wastes are less, sodium ion and chloride ion impurities are not contained, and the purity of the ethylene sulfate is high.

This invention discloses a method for preparing 1,1-ethylene glycol diacetate, characterized by: using acetic acid and vinyl acetate as raw materials, reacting under reflux at 80-85°C in the presence of a catalyst; after the reaction is complete, turning off the heating, adding sodium acetate to the reaction vessel, continuing the reaction to neutralize the catalyst; after the reaction is complete, separating the solid from the mixture, and concentrating the liquid phase to obtain the target product 1,1-ethylene glycol diacetate. The catalyst is at least one selected from concentrated sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid. The raw materials are safe and environmentally friendly, inexpensive, and can be reacted under normal pressure, requiring less sophisticated equipment, facilitating industrial production, and yielding high purity.

This invention relates to a polyester resin for 50 / 50 blended powder coatings. This polyester resin is obtained by reacting raw materials including glycerin black lead, ethylene glycol, diethylene glycol, terephthalic acid, 4,4'-biphenyl dicarboxylic acid, succinic acid, and pyromellitic dianhydride. The resulting product exhibits good impact resistance, a gloss level generally above 92%, and other properties such as adhesion that basically meet the application requirements of 50 / 50 blended powder coatings. Due to the comprehensive utilization of the effective components of glycerin black lead, it has the advantages of low cost and outstanding environmental performance.

The invention provides anti-fog glass and a preparation method thereof. The anti-fog glass comprises a glass substrate, a bonding layer and an anti-fog layer, wherein the bonding layer is arranged between the anti-fog layer and the glass substrate; the coating of the anti-fog layer comprises the following components in parts by weight: 70-90 parts of a first monomer, 5-15 parts of a second monomer, 3-6 parts of a cross-linking agent and 5-10 parts of a photoinitiator; the first monomer comprises one or a combination of more than two of hydroxyethyl methylacrylate, polyethylene glycol diacrylate, N-hydroxymethyl acrylamide, methacrylamide, N-isopropylacrylamide and N, N-dimethylacrylamide; the second monomer is prepared from one or a combination of more than two of trifluoroethyl methacrylate, methyl methacrylate, butyl acrylate, ethylene glycol dimethacrylate, glycidyl methacrylate, benzyl methacrylate and 2-acrylic acid-2-hydroxy-3-phenoxy propyl ester. The anti-fog glass disclosed by the invention has the advantages of anti-fog property, moisture resistance, salt fog resistance and wear resistance.

Disclosed herein are various embodiments pertaining to continuous processes for making ethylene glycol diacetate, also known as 1,2-diacetoxyethane, by esterification of monoethylene glycol to 2-hydroxyethyl acetate and the esterification of 2-hydroxyethyl acetate to ethylene glycol diacetate. Various embodiments herein use reactive distillation in processes promising enhanced economic viability in the production of high-quality ethylene glycol diacetate.

To provide a method for synthesizing a capped cationic polymer.SOLUTION: Provided is a method that includes: (a) contacting poly(ethylene glycol) diacrylate monomers and 3-amino-1-propanol to form a poly(ethylene glycol) diacrylate / 3-amino-1-propanol cationic polymer by Michael Addition, wherein the molar ratio of the poly(ethylene glycol) diacrylate monomers to 3-amino-1-propanol is greater than 1, and the cationic polymer is acrylate-terminated; and (b) contacting terminal acrylate groups of the cationic polymer with capping molecules comprising amine groups to form the capped cationic polymer by Michael Addition, wherein the capped cationic polymer comprises no acrylate groups.SELECTED DRAWING: Figure 1A

The present invention provides a method for preparing a 3D printed silicon-based ceramic core, and the method is as follows: After mixing 1,6-ethylene glycol diacrylate, epoxy acrylate, trimethylolpropane triacrylate and polyurethane acrylate, add 2,4,6-trimethylbenzoyl-ethoxy-phenyl phosphine oxide, oleic acid and dispersant BYK-111, and stir and mix to obtain a premixed liquid; After mixing fused quartz powder, white fused alumina and zirconium silicate, add metallic Si powder to obtain a mixture; Add the premixed liquid to the mixture, ball mill to obtain a ceramic slurry, prepare a ceramic core blank by 3D printing, clean, dry, and then calcine to obtain a 3D printed silicon-based ceramic core. It also provides an application for manufacturing hollow blades. The 3D printed silicon-based ceramic core prepared by the present invention has excellent mechanical properties and can be used for manufacturing hollow blades.

To provide an oil-in-water emulsion cosmetic with high moisturizing effect and viscosity stability. [Solution] An oil-in-water emulsion cosmetic comprising (A) a hydrophilic nonionic surfactant, (B) a higher aliphatic alcohol having 12 or more carbon atoms, (C) a polyethylene glycol difatty acid ester with a polymerization number of 20 or less of polyoxyethylene glycol, (D) an oil, and (E) water.

The various embodiments disclosed herein relate to a process for producing vinyl acetate monomer (VAM) from ethylene glycol diacetate (GDA) by thermal cracking in the presence of a substantially non-reactive liquid. The liquid phase enhances heat transfer, improves selectivity, and reduces fouling. The process operates in a continuous or discontinuous phase, optimizing efficiency and enabling higher yields of VAM with improved reactor performance.

The invention discloses a fast-curing high-permeability chemical grouting material as well as a preparation method and application thereof. The chemical grouting material consists of a material A and a material B, the material A is composed of water glass and a functional additive; the material B is prepared from ethylene glycol diacetate and water; the functional additive is one or a mixture of two or more of a coagulation accelerator, a viscosity modifier, a reinforcing agent and a water-resistant agent; in the material B, the volume ratio of ethylene glycol diacetate to water is 1: (1-3); the volume ratio of the material A to the material B is (60-90): (3-30); the preparation method comprises the following steps: uniformly stirring and mixing the water glass and the functional additive to obtain a material A; uniformly stirring and mixing ethylene glycol diacetate and water to obtain a material B; before grouting, the material A and the material B are uniformly mixed and then immediately used for treatment projects such as reinforcement and water stop in grey sandstone stratums, and the problems that an existing grouting material is high in viscosity, curing time is difficult to regulate and control, and the strength of a cured body is insufficient can be solved.

The invention provides an exosome oral soluble film with a multi-targeting function, which is prepared from the following components in parts by weight: 10 to 20 parts of active substances, 20 to 60 parts of carrier materials for wrapping exosomes or drug-loaded exosomes, 50 to 100 parts of film-forming agents, 20 to 40 parts of disintegrating agents, 10 to 25 parts of plasticizers, 1 to 5 parts of flavoring agents and 1 to 10 parts of antioxidants, wherein the active substance is an exosome or a drug-loaded exosome, and the carrier material is a polylactic acid-glycolic acid copolymer-sulfydryl group, polyethylene glycol and polyethylene glycol diacrylate. According to the scheme, the carrier material entrapped with the exosome has a dual targeting effect, so that the exosome or the exosome loaded with the medicine can accurately reach the ulceration position of the colonic mucosa, and accurate treatment is achieved; and the exosome is administrated in an oral dissolution manner, so that a patient can take the exosome with high compliance.

The invention relates to hydrogel microparticles, compositions and uses thereof. The present invention provides spherical or elliptical non-alginate hydrogel microparticles for local delivery and sustained release of therapeutic cells and / or tissues at an implantation site, the microparticles comprising a 3-dimensional substrate of a covalently crosslinked non-alginate polymer compound and a therapeutically effective amount of cells and / or tissues embedded therein, wherein the cells have a viability of at least 50%, the microparticles have a size of greater than 30 [mu] m, the non-alginate hydrogel microparticles are formed without using an oil emulsion, the polymer compound is polyethylene glycol vinyl sulfone or acrylated hyaluronic acid, the matrix further includes a cross-linking agent selected from the group consisting of dithiothreitol, polyethylene glycol dithiol, and ethylene glycol bis-mercaptoacetate, cross-linked with the non-alginate polymer compound. Compositions comprising such hydrogel microparticles and their use for the preparation of medicaments are also described.

The application belongs to the technical field of oil field chemical additives, and provides a fluid loss additive for oil well cement and a preparation method thereof.The fluid loss additive for oil well cement comprises raw materials, i.e., a high molecular polymer, a composite hydration agent, an additive, deionized water and potassium persulfate; the high molecular polymer is formed by graft polymerization of sulfonated polyether sulfone, acrylonitrile, hydroxyethyl methacrylate and sodium allyl sulfonate monomers; and the composite hydration agent is formed by compounding and cross-linking of TPEG-2400, silica ash, metakaolin and polyethylene glycol diacrylate.The preparation method comprises the following steps: mixing the above raw materials, and obtaining the fluid loss additive after constant temperature stirring reaction.The fluid loss additive for oil well cement can utilize the synergistic effect among raw materials, improve the temperature resistance and salt resistance of the fluid loss additive, the fluid loss performance and the cement stone strength, and has the advantages of simple preparation process, easily obtained raw materials, controllable cost, suitability for industrialized scale-up production, adaptability to cementing operation in deep well, ultra-deep well and high salinity environment, etc.

The invention provides a quality detection method and a quality standard of polyethylene glycol 3350 powder, and belongs to the technical field of medicine quality detection. Detecting content, molecular weight and molecular weight distribution; aldehyde impurities are detected; detecting ethylene glycol, diethylene glycol and triethylene glycol; by comprehensively covering multi-dimensional detection items and quality parameters, comprehensive evaluation of product quality is achieved, accuracy and reliability of results are guaranteed by means of an accurate and standard detection method, drug use risks are reduced by strictly controlling impurity limits, production circulation links are standardized by means of full-chain quality control, and production efficiency is improved. The specific microbial limit standard is used for preventing pollution, the stability, the safety and the compliance of the product quality are effectively guaranteed under the combined action of multiple aspects, and a scientific and rigorous basis is provided for production, inspection and use of the polyethylene glycol 3350 powder.

The application discloses a synthesis method of polyethylene terephthalate, which utilizes terephthalic acid and ethylene glycol diacetate as polymerization raw materials, and obtains polyethylene terephthalate through de-acetate exchange polymerization under the action of a catalyst. In the method, the non-expected condensation mode (such as forming a diethylene glycol fragment) does not appear to affect the polymer performance; and because EG is not used, the tolerance to oxygen is stronger during the reaction process, and the produced PET will be more resistant to oxidation and yellowing. On the other hand, the boiling point of EGDA is lower than that of EG, so that EGDA is easier to separate from the system in theory, and the evaporated EGDA can be directly used for the next polymerization without other impurities.