43 results about "Glycol formation" patented technology

The present invention provides a process treating the cycle gas from an ethylene oxide reactor to avoid heat losses in a carbonate scrubbing system as well as glycol formation in the carbonate scrubbing and catalyst contamination upon cycle gas recycle.

The invention relates to a method for separating glycol and 1,2-butanediol, which mainly solves the problems of high investment and energy consumption due to the fact that a very high reflux ratio and very high number of theoretical plates are required when a common rectification method is employed to separate and purify a material flow containing glycol and 1,2-butanediol, and severe separation conditions or a non-ideal separation effect when a common azeotropic rectification method is employed. The method better solves the problem by employing the technical scheme that the material flow containing glycol and 1,2-butanediol and a reactor enters from the upper part and the lower part of a reaction-azeotrope rectification tower respectively, a generated reaction product forms an azeotrope with glycol at the same time, a tower kettle obtains a material flow containing 1,2-butanediol, and after the azeotrope distilled from the tower top is subjected to condensation phase splitting, a glycol-rich phase at the lower layer is further refined to form a glycol product. The method can be used for industrial production of separating the material flow containing glycol and 1,2-butanediol.

The invention provides a visible-light response type neodymium-doped bismuth ferrite nanometer photocatalyst. The neodymium-doped bismuth ferrite nanometer photocatalyst is characterized in that the chemical formula is Bi(1-x)NdxFeO3(0<x<=0.02), the photocatalyst is of a porous nanometer structure, and the particle size is within the range of 100-300 nm. Meanwhile, the invention further provides a preparation method of the nanometer photocatalyst. The preparation method is characterized in that ferric nitrate, ferric nitrate and neodymium nitrate are dissolved into an ethylene glycol proportionally to form a solution, a proper amount of tartaric acid is added to be used as a chelating agent, uniform mixing is performed, heating is performed to form sol to be dried, roasting is performed after grinding is performed, and then neodymium-doped bismuth ferrite nanometer powder can be obtained. The obtained neodymium-doped bismuth ferrite nanometer photocatalyst has the good visible-light response and light catalytic performance, the preparation method is simple, the technological conditions are easy to regulate and control, the cost is low, no pollution is caused, and industrial production, application and popularization are easy.

The invention discloses a clad modified layered cathode material of a lithium-ion battery and a preparation method of the layered cathode material. The material is obtained by evenly covering the layered cathode material of the lithium-ion battery by a Li2TiO3 thin film. The preparation method comprises the following steps: (1) dissolving a titanium source in an ethanol solution, and dropwise adding glycol to form a solution A; dissolving a lithium salt and a complexing agent in deionized water to form a solution B; (2) mixing the two solutions and regulating the pH value of the mixed solution to the range of 5-7 by use of a weakly alkaline liquor or a weakly acidic liquor; (3) adding the layered cathode material of the lithium-ion battery to a suspension, and heating and stirring to obtain a sol; drying the sol to obtain a precursor; grinding and annealing the precursor to obtain the target product. The method is used for modifying the layered cathode material of the lithium-ion battery by covering the layered cathode material with the Li2TiO3 thin film; the surface thin film covering the cathode material by use of the method is clad evenly, and the method is mature and reliable.

The invention discloses a preparation method of a high-performance aluminum and potassium co-doped sodium vanadium fluorophosphate / carbon composite material. According to the preparation method, a uniform solution is formed from a reaction raw material and low-molecular polyethylene glycol, a high-activity aluminum-doped vanadium phosphate / carbon composite material is prepared by combining carbonthermal reduction reaction, and the high-performance Na<1-x>K<x>V<1-y>Al<y>PO<4>F / C composite material is obtained by high-temperature reaction under inert atmosphere by taking the aluminum-doped vanadium phosphate / carbon composite material as the raw material. Carbon with high electron conductivity is generated from polyethylene glycol and a carbohydrate under a high-temperature inert atmospherecondition in an in-situ way, carbon can generate a reduction agent in carbon thermal reduction reaction, and growth and agglomeration of product particles also can be prevented; a larger passage is provided for sodium ion mobility by sodium doped with potassium, and the structural stability of sodium vanadium fluorophosphate is improved by vanadium doped with aluminum; and by combining the advantages of high electron conductivity, large sodium ion mobility passage and structural stability, the aluminum and potassium co-doped sodium vanadium fluorophosphates / carbon composite material has excellent electrochemical performance.

The invention belongs to the field of nanometer materials and nanometer technologies and in particular relates to a silkworm-chrysalis-shaped PbS quantum dot / graphene composite material and a preparation method thereof. The preparation method comprises the steps of evenly dispersing graphene oxide into ethylene glycol to form graphene oxide-ethylene glycol dispersion liquid; adding lead nitrate powder into the graphene oxide-ethylene glycol dispersion liquid to obtain lead nitrate-graphene-ethylene glycol dispersion liquid; dissolving sodium sulphide into ethylene glycol to form sodium sulphide-ethylene glycol solution; processing the lead nitrate-graphene-ethylene glycol dispersion liquid through ultrasound, adding the sodium sulphide-ethylene glycol solution into the lead nitrate-graphene-ethylene glycol drop by drop and mechanically stirring to obtain PbS quantum dot-graphene dispersion liquid after reaction; then centrifugally separating, washing and drying to obtain the PbS quantum dot / graphene composite material. The prepared PbS quantum dot / graphene composite material is of a silkworm-chrysalis-shaped three-dimension structure, even in quantum dot particle size and excellent in gas-sensitive property to ammonia gas in a room temperature and a low temperature.

The invention relates to a preparation method for a front electrode of an organic thin film solar cell. The preparation method comprises the following steps of (a) taking a glass slide as the substrate, and sputtering an AZO thin film on the substrate; (b) adding polyvinyl pyrrolidone, 1-methyl-3 ethyl imidazolium bromide and ethylene glycol into a reaction kettle to form a mixed solution; next, adding an ethylene glycol solution of silver nitrate to the mixed solution, sealing and placing the mixed solution at a temperature of 100-120 DEG C to react for 1-5h, then carrying out centrifuging, cleaning and carrying out ultrasonic dispersion on the mixed solution to obtain a silver nanowire water solution; (c) adding a chloroauric acid solution and an oxidizing agent to the silver nanowire water solution to react at a temperature of 5-30 DEG C for 5-10min, next, adding a reducing agent to the mixture to continue to react for 5-10min; then centrifuging, washing and evaporating the mixture to remove water, and drying the mixture to obtain a gold-coated silver nanowire; (d) dispersing the gold-coated silver nanowire into an isopropanol solution, and then coating the surface of the AZO thin film with the processed isopropanol solution in a spin-coating manner to a obtain a composite layer sample; and (e) sputtering the AZO thin film on the surface of the composite layer sample. By adoption of the preparation method, the efficiency of the organic thin film solar cell is improved.

The invention discloses paclitaxel modified by branched polyethylene glycol and a preparation method of paclitaxel, wherein the structure of the paclitaxel modified by branched polyethylene glycol is shown as the formula I. According to the preparation method, in a solvent, branched polyethylene glycol and paclitaxel formed by connecting two amino groups of lysine with polyethylene glycol respectively are taken as raw materials, 4-dimethylaminopyridine is taken as a catalyst, and N,N'-dicyclohexylcarbodiimide is taken as a condensating agent, and the branched methoxy polyethylene glycol paclitaxel compound is obtained through reaction. The formula I is shown in the description.

The invention relates to an antistatic polyethylene glycol terephthalate composite material. Glycol, terephthalic acid and nano antistatic agent-glycol sol are polymerized, the esterification reaction temperature is 200-290 DEG C, and the pressure is 0.1-0.5MPa; the low-vacuum polycondensation reaction temperature is 200-290 DEG C, the pressure is reduced from normal pressure to 1,000Pa; and the high-vacuum polycondensation reaction temperature is 250-300 DEG C, and the reaction vacuum degree is 100-50Pa. The nano antistatic agent-glycol sol is formed by nano carbon black, nano metal, nano metal compounds and glycol. A nano antistatic agent accounts for 0.1-10% of the weight of the polyethylene glycol terephthalate and accounts for 1-10% of the weight of the nano antistatic agent-glycol sol. The intrinsic viscosity of the material is 0.55-0.75dL / g, and the volume resistivity of a fiber is 108 ohms / cm-109 ohms / cm.

The invention discloses graphene composite rubber for an automobile air inlet hose and a preparation method thereof. The composite rubber is prepared by the following steps: a, adding terephthalic acid into ethylene glycol to form oil phase liquid; b, mixing graphene, polyethylene glycol octylphenyl ether with water, then adding the oil phase liquid, and drying the mixture and grinding the mixtureinto microspheres after a reaction; c, mixing the microspheres with nitrile rubber latex, and carrying out flocculation to obtain coprecipitation glue; and d, compounding the coprecipitation glue with ethylene propylene diene monomer rubber, stearic acid, aromatic oil, an accelerant and a cross-linking agent to obtain the high-temperature oil-resistant graphene composite rubber. The method has the benefits that: the composite rubber is modified by graphene / polyethylene terephthalate powder microspheres, and the prepared material has excellent high-temperature resistance and oil resistance, and can be widely applied to automobile air inlet hoses.

The invention belongs to the technical field of two-aqueous-phase extraction of viruses, and discloses a method for concentrating and purifying porcine SenecaviusA (SVA) particles through two-aqueous-phase extraction. The method comprises the following steps: performing SVA reproduction; carrying out indirect immunofluorescence identification on the SVA; establishing a three-step aqueous two-phase extraction method; determining the content of SVA; carrying out a western blot test; and carrying out electron microscope identification on SVA. After low-concentration polyethylene glycol and inorganic salt are added into an SVA culture solution, cell debris is removed, and then polyethylene glycol is added to form an aqueous two-phase system, so that concentrated and purified porcine SVA virus particles can be quickly obtained; rapid separation of virus particles can be realized through an aqueous two-phase extraction technology, the recovery rate and the purity of the virus particles are relatively high, the process is simple, and the cost is low; through a three-step aqueous two-phase extraction method, the purpose of concentrating and purifying the porcine SVA virus particles from the cell culture fluid is achieved, and the method can be applied to laboratory and large-scale production at the same time.

The invention provides a high-barrier-property modified ZnO / PET protective film and a preparation method thereof, belonging to the technical field of synthesis of polymer composite materials. The preparation method comprises the following steps: preparing modified nanometer ZnO by using zinc stearate as a zinc source and a modifier, mixing the modified nanometer ZnO with ethylene glycol to obtaina ZnO / ethylene glycol complex, carrying out in-situ polymerization on the ZnO / ethylene glycol complex and terephthalic acid to obtain PET modified master batch, and finally carrying out injection molding on the PET modified master batch and PET resin. The modified nanometer ZnO of the protective film with high barrier property prepared by the method disclosed by the invention is not easy to agglomerate since the nanometer ZnO forms the complex with ethylene glycol, so the protective film has huge surface area and hydrophobic capacity, has excellent water vapor blocking capacity, prevents external water vapor from entering the inner side of the protective film, can absorb water vapor on the inner side of the protective film, and becomes a substitute with more excellent performance in the fields of biomedical packaging, food preservation and the like.

The invention relates to a method for preparing hafnium boride powder. The method comprises the following steps: dissolving a hafnium source compound in a first solvent to form a first solution; dissolving a boron source compound and a carbon source compound in a second solvent, and adding polyethylene glycol to form a second solution; adding the first solution into the second solution, and collecting the generated precipitate; and drying the collected precipitate, grinding the dried precipitate into powder, and carrying out high-temperature calcination to prepare the hafnium boride powder. The preparation process is simple, the reaction process is easy to control, the production period is short, the cost is low, the prepared hafnium boride powder has high purity, small particle size, narrow particle size distribution and good microstructure, and the mechanical property and sintering driving force of a sintered body can be enhanced in the subsequent forming process.

The invention relates to the production and use of polyester polyols, formed from at least one carboxylic acid anhydride and ethylene glycol, wherein a specialized reaction control substantially suppresses the formation of 1,4-dioxane from diethylene glycol.

The invention belongs to the field of helmet functional materials, and particularly relates to a foaming composite material for a bicycle safety helmet, and a preparation method thereof. The preparation method comprises: dispersing a premix formed by a silicon dioxide wet gel, polyether and Arabic gum powder into a pre-reacted polyurethane oligomer; further carrying out a foaming reaction on polyether and the oligomer while uniformly dispersing a wet gel and Arabic gum in polyurethane foam; and immersing polyethylene glycol 600, and adsorbing to form the uniform non-Newtonian fluid from silica, Arabic gum, polyethylene glycol 600 in polyurethane foam. According to the invention, the foaming material generally has good softness and good buffer property during the use, so that the helmet isendowed with good comfort; and when the helmet is subjected to violent collision, the non-Newtonian fluid formed by silicon dioxide, Arabic gum and polyethylene glycol 600 in the composite foaming material is rapidly gathered and becomes hard from soft due to rapid impact, so that the helmet is not prone to being broken and pierced, and the head is protected against injuries.

Embodiments of the current invention include a hydrogel formed from crosslinked polyethylene glycol into which acrylated glucose oxidase has been immobilized through crosslinking to the gel. These hydrogels can be used to create hypoxia under ambient conditions for at least 72 hours and can be used to create hypoxic gradients. These embodiments permit the study of cells under a variety of hypoxic conditions.

The invention provides a high-barrier modified ZnO / PET protective film and a preparation method thereof, belonging to the technical field of polymer composite material synthesis. The preparation method comprises: using zinc stearate as a zinc source and a modifying agent to prepare modified nano-ZnO, then mixing the modified nano-ZnO with ethylene glycol to obtain a ZnO / ethylene glycol complex, and then mixing with terephthalic In-situ polymerization of formic acid to obtain PET modified masterbatch, and finally PET modified masterbatch and PET resin for injection molding. The modified nano-ZnO of a high barrier protective film prepared by the method of the present invention is not easy to agglomerate due to the formation of a complex with ethylene glycol, has a huge surface area and hydrophobic ability, has an excellent ability to block water vapor, and avoids external water vapor. The steam enters the inner side of the protective film, and at the same time, it can absorb the water vapor inside the protective film, making it a more excellent substitute in the fields of biomedical packaging and food preservation.

The invention discloses a preparation method of an anti-freezing asphalt mixture. The preparation method comprises the following steps: S1, preparing and pretreating raw materials; s2, preparing a core material solution; s3, forming a wall material solution; s4, mixing the core material solution and the wall material solution according to a ratio of 4: 1, drying and curing to prepare an anti-freezing agent; s5, preparing an asphalt mixture, namely doping the anti-freezing agent prepared in the step S4 into the asphalt mixture according to a replacement rate of 30-60% to prepare a sample; and S6, detecting the characteristics of the sample through a freeze-thaw cycle experiment, and producing finished products in batches after the sample is detected to be qualified. When raw materials for preparing the anti-freezing agent are selected, polyethylene glycol is adopted as a slow-release base, trisodium phosphate is adopted as a corrosion inhibition base, through the synergistic effect of the slow-release base and the corrosion inhibition base, polyethylene glycol is utilized to form a hydrophobic shell to delay release of chloride ions, trisodium phosphate is hydrolyzed to generate a calcium phosphate passive film to inhibit corrosion of steel bars, and the corrosion resistance of the steel bars is improved. The two synergistically prolong the chloride ion release period and reduce the corrosion rate of the carbon steel.

The present invention provides a method for producing a biaxially oriented polyester film that can be used in industrial applications and packaging applications. A method for producing a biaxially oriented polyester film, characterized in that it comprises the steps of: feeding a polyester resin into an extruder; extruding the melted polyester resin from the extruder to obtain 250- A step of melting the resin sheet at 310°C; a step of bringing the molten resin sheet into close contact with a cooling roll by an electrostatic application method to obtain an unstretched sheet; and a step of biaxially stretching the above-mentioned unstretched sheet, and the above-mentioned polyester The resin satisfies the following (A) to (C): (A) the above-mentioned polyester resin contains polyethylene furandicarboxylate resin formed by furandicarboxylic acid and ethylene glycol; (B) the intrinsic viscosity of the above-mentioned polyester resin It is more than 0.50dL / g; (C) the melting resistivity value at 250°C of the above-mentioned polyester resin is 3.0×10 7 Ω·cm or less.

The invention discloses a polyethylene glycol-modified paclitaxel and a preparation method thereof. The structure of the polyethylene glycol-modified paclitaxel is shown in formula I. The preparation method is to connect two amino groups of lysine to poly Polyethylene glycol formed from ethylene glycol and paclitaxel (PTX) are used as raw materials, 4-dimethylaminopyridine (DMAP) is used as a catalyst, and dicyclohexylcarbodiimide (DCC) is used as a condensation agent to obtain monomethoxy based peg-paclitaxel compound. The compound is used in the preparation of medicine for treating cancer.

The invention discloses an application of a rosiglitazone nano preparation in treating vascular restenosis. A rosiglitazone composition contains rosiglitazone, a polylactic acid-polyglycolic acid copolymer, lecithin and distearyl phosphatidyl ethanolamine-polyethylene glycol 2000. A rosiglitazone nano preparation is nano particles formed by rosiglitazone, polylactic acid-polyglycolic acid copolymer, lecithin and distearyl phosphatidyl ethanolamine-polyethylene glycol 2000, the structure is of a spherical structure, and the particle size is between 250 nm and 300 nm. The invention also discloses a preparation method of the rosiglitazone nano preparation, and the rosiglitazone nano preparation can effectively treat vascular restenosis after implanting of an intravascular stent, and can reduce the toxicity of rosiglitazone and improve the biological safety.

The invention provides a palladium-nickel-titanium ethylene glycol coordination polymer heterogeneous catalyst as well as a preparation method and an application thereof. The invention provides a synthesis method of a micron-sized rod-like heterogeneous catalyst of a palladium-nickel-titanium ethylene glycol coordination polymer, which is simple and easy to obtain and can be massively prepared at one time. The preparation method comprises the following specific preparation steps: firstly, dissolving palladium salt and nickel salt in ethylene glycol to form a 0.1-0.4 mol.L <-1 > solution, then dissolving a titanium source in the ethylene glycol solution, and continuously stirring at room temperature to prepare the micron-sized rod-like heterogeneous catalyst material. The length of the rod-like structure is 0.8-5 microns, and the diameter of the rod-like structure is 100-120 nm. The prepared material can effectively catalyze the Suzuki coupling reaction, and the heterogeneous catalyst is high in catalytic efficiency, convenient to recycle and reusable, and has important significance in industrial production.

The application belongs to the technical field of converting waste plastics into high value-added materials, and discloses a method for converting waste PET into metal-organic framework material by ball milling and electrochemical degradation, which comprises the following steps: S1, ball milling waste PET and solid strong base compound together; S2, dissolving the ball milling product in deionized water; S3, adding conductive salt to obtain electrolyte; S4, selecting corresponding metal element foil to obtain metal M sheet; S5, taking the metal M sheet as an anode to perform electrochemical reaction, and thus MOF material is obtained. The application improves the process flow design of the preparation method, degrades the waste PET into disodium terephthalate and ethylene glycol by mechanical ball milling to form electrolyte, and then performs subsequent electrochemical treatment, so that MOF is synthesized, and the obtained MOF has better oxygen evolution reaction (OER) performance than other MOF materials, which breaks through the expectation.

The invention relates to a method for preparing a perovskite catalyst for a metal-air battery. The chemical formula of the perovskite catalyst is: La x Y (1‑x) ZO 3 ; In the formula, 0<x<1, Y is Sr or Co, and Z is Mn or Fe; It comprises the following steps: (a) take by weighing lanthanum nitrate, nitric acid Y and nitric acid for x: 1-x: l in molar ratio Z, respectively dissolved in water, and then add ethylene glycol to form a mixed solution; (b) add a complexing agent to the mixed solution, adjust its pH value to 6-7 with ammonia water, and carry out stirring and complexing; then move to a constant temperature Stir in a water bath until gel is formed, then dry and grind into powder; (c) calcining the powder at 250-500°C. It does not need to be roasted at a high temperature above 500° C., which simplifies the preparation process and difficulty, and reduces the cost.

Provided is a method for producing a biaxially oriented polyester film that can be used for industrial applications and packaging applications. The method for producing a biaxially oriented polyesterfilm includes: a step in which a polyester resin is introduced into an extruder; a step in which the melted polyester resin is extruded from the extruder and a melted resin sheet having a temperatureof 250-310 DEG C is obtained; a step in which the melted resin sheet is brought into close contact with a cooling roller by applying an electrostatic charge and an unstretched sheet is obtained; and astep in which the unstretched sheet is biaxially stretched. The method for producing a biaxially oriented polyester film is characterized in that the polyester resin satisfies the conditions (A) to (C) indicated below. (A) The polyester resin contains a polyethylene furandicarboxylate resin comprising furandicarboxylic acid and ethylene glycol. (B) The intrinsic viscosity of the polyester resin is 0.50 dL / g or more. (C) The melt resistivity of the polyester resin at 250 DEG C is 3.0*107 Omega.cm or less.

The invention provides a carboxylic acid derivative modified beta-cyclodextrin chiral chromatographic stationary phase material which is prepared by the following steps: dissolving beta-cyclodextrin and carboxylic acid in a deep eutectic solvent formed by choline chloride and ethylene glycol, and stirring and reacting at 80-85 DEG C for 25-30 minutes; adding aminopropyl silica gel, carbodiimide and L-phenylalanine into the mixed solution, and continuing to stir and react for 10-12 hours; and after the reaction is finished, filtering, washing solid products with acetone and methanol respectively, and drying in vacuum to obtain the product. The carboxylic acid derivative modified beta-cyclodextrin chiral material prepared by the invention shows high selectivity and a wide raceme separation range, and can selectively separate aromatic secondary alcohol, benzoin, flavanone and triazole chiral compounds thereof in a positive and negative phase mode. In addition, the prepared chiral material is large in surface bonding amount, good in repeatability and high in chiral resolution performance, and the preparation process is green and simple.

A process for the preparation of (S)-omeprazole from racemic omeprazole via the formation of an inclusion complex with (S)-1,1,2-triphenyl-1,2-ethanediol. (S)-Omeprazole is recovered in a substantially optically pure form either in neutral form or as a pharmaceutically acceptable salt or as its solvates including hydrates. The (S)-omeprazole 2[(S)-1,1,2-triphenyl-1,2-ethanediol] inclusion complex is new. This resolution process proceeds with high yields and high optical purity.

The invention discloses a preparation method of a diamine ternary eutectic solvent and application of the diamine ternary eutectic solvent to efficient capture of SO2. According to the invention, different amine substances and different proportions thereof in the diamine ternary eutectic solvent are regulated and controlled, and the diamine ternary eutectic solvent with different amine substances and different proportions is designed and synthesized and is applied to SO2 absorption. Amino groups provided by diamine substances in the diamine ternary eutectic solvent and ethylene glycol form hydrogen bonds, strong charge interaction is formed between the hydrogen bonds and SO2, and thus efficient capture of SO2 is achieved, the diamine ternary eutectic solvent is used as an absorbent to absorb SO2 gas, the absorption pressure is 0-1.5 bar, the absorption temperature is 0-80 DEG C, and the absorption time is 1-6 h. After absorption, SO2 is easy to desorb, the desorption temperature is 50-100 DEG C, and the desorption time is about 2-6 hours. Compared with a traditional SO2 trapping method, the highest absorption capacity can reach 0.82 g SO2 / g DES.

The application discloses an enzyme preparation for alkali-resistant degradable plastics and a preparation method thereof, and belongs to the technical field of plastic degradation enzyme preparations. The preparation process of the enzyme preparation comprises the following steps: synthesizing a norbornene intermediate and a full phosphate cup [6] arene, grafting a tetrazine functionalized four-arm polyethylene glycol through a DA reaction to form a three-dimensional cross-linked carrier, and then loading a mixed enzyme composed of multiple enzymes. The rigid cavity of the cup [6] arene can form specific inclusion with enzyme molecules, the phosphate group can enhance the enzyme-carrier binding force, and the cross-linked network can improve the stability of the carrier and provide multiple loading sites. The multi-enzyme synergistic system can destroy the surface structure of plastics, degrade the composite filler and cut the ester bond. The enzyme activity retention rate of the enzyme preparation in an alkaline environment is more than 85%, the half-life at 50 DEG C is more than 110h, the weight loss rates of polylactic acid film and composite materials containing 30% starch filler are both more than 92%, and the degradation efficiency of degradable plastics in an alkaline environment is significantly improved.

The invention provides a recovery method for chemical recovery of waste pet, which comprises the following steps: feeding waste pet into a twin-screw extruder, extruding, melting and conveying the waste pet through screws, adding ethylene glycol into the twin-screw extruder, and depolymerizing to generate BHET, gaseous ethylene glycol and water; the depolymerized product BHET is conveyed to an esterification kettle, a catalyst and a stabilizer are synchronously added in proportion for an esterification reaction to discharge excessive ethylene glycol, then pre-polycondensation and final polycondensation are carried out for polycondensation polymerization, meanwhile, ethylene glycol is further removed, and copolyester with high molecular weight is formed. According to the method disclosed by the invention, the waste pet material is recycled and reused, so that the use cost of the pet is reduced; by adopting a mode of combining pre-polycondensation and final polycondensation, the production efficiency and the purity of pet are improved.