123 results about "Polyethylene Terephthalates" patented technology

The utility model relates to the technical field of PET (Polyethylene Terephthalate) sheet cooling, and discloses a cooling device after PET sheet extrusion, which comprises an operation table, a cooling table is fixed on one side of the operation table, a plurality of rolling shafts are arranged in the cooling table at intervals, and a cooling structure is arranged above the cooling table. Through the arrangement of the cooling structure, a sheet sequentially penetrates through the three cooling rollers, the surface temperature of the sheet is rapidly reduced to a reasonable range through contact of the cooling rollers, the internal and external temperature difference is reduced, then the sheet enters the cooling bin, cold air is circularly sprayed out through the upper and lower cold air pipes, and the upper and lower surfaces of the sheet are uniformly cooled; a worker conveys cooling water to the atomization spray head through the conveying pipe and the flow dividing bin, sprayed water mist is distributed on the surface of the sheet along with cold air, heat is rapidly taken away after heat absorption and vaporization, the heat conduction efficiency is remarkably improved through combination of the cold air and the water mist, the sheet is cooled more efficiently and evenly, and the surface quality and the size stability of the sheet are further guaranteed.

Disclosed is a process for hydrolytic depolymerization of a polyamide contained in a chemical feedstock F, wherein the process comprises: providing the chemical feedstock F; providing a liquid aqueous stream SW; preparing a mixture comprising the raw material F and the liquid aqueous stream SW and subjecting said mixture to polyamide 6 depolymerization conditions in a chemical reaction unit UR, thereby obtaining an aqueous stream SE exiting the UR, the stream SE comprising epsilon-caprolactam, wherein the mixture to be subjected to polyamide 6 depolymerization conditions comprises polyamide 6 and further comprises polyethylene terephthalate and polyamide 6.6 in a mass ratio rS = (mPA6.6 + mPET) / mPA6, wherein 0.01 < = rS < = 2.5.

The invention discloses a micro-plastic degrading bacterium P.ataveovii and application thereof, and belongs to the technical field of microorganisms. According to the invention, a strain of Priestia aryabhattai BK12 is separated and screened from plastic wastes, and the plastic degradation capability of the Priestia aryabhattai BK12 is deeply explored. A research result shows that the P.avenae BK12 can be used for efficiently degrading the PET (Polyethylene Terephthalate), and the P.avenae BK12 can be used for efficiently degrading the PET (Polyethylene Terephthalate), so that the P.avenae BK12 can be used for efficiently degrading the PET (Polyethylene Terephthalate). The invention provides a new microbial resource for the development of a plastic degradation agent, contributes to promoting the development of a biodegradable plastic technology and solving the problem of environmental pollution caused by PET, and assists in realizing the goal of green and sustainable development.

The present application provides compositions, excipient systems, methods, and dispensers for delivery of active pharmaceutical ingredients (APIs). In one example, a composition is provided comprising an active pharmaceutical ingredient; one or more excipient compound(s) selected from a hydroxyalkyl ester of an aliphatic fatty acid, a hydroxyacid alkyl ester, an alkyl ester of a fatty acid, and combinations thereof; and a semi-fluorinated alkane compound. In another example, an excipient system is provided comprising one or more excipient compound(s) selected from a hydroxyalkyl ester of an aliphatic fatty acid, a hydroxyacid alkyl ester, an alkyl ester of a fatty acid, and combinations thereof and a semi-fluorinated alkane compound. Dispensers containing the compositions are also provided and include glass and polyethylene terephthalate dispensers or containers. Methods of using the compositions are also provided and include a method for treating a condition in a subject comprising administering the compositions to the subject.

The present disclosure relates to methods designed for the depolymerization of poly(ethylene terephthalate) (PET) and the subsequent recovery and reuse of the PET deconstruction products. Among other things, the present disclosure describes methods for generating enriched reaction media, where the method includes providing a first amount of PET to a reaction chamber, performing depolymerization of the PET, thereby generating a first reaction media, adding a second amount of PET to the first reaction media, and performing depolymerization on the combined second amount of PET and the first reaction media, thereby generating an enriched hydrolysis reaction media, thereby enabling improved downstream separation of the deconstruction products.

The invention discloses polyethylene glycol terephthalate hydrolase PmPETase and application thereof.The hydrolase PmPETase is protein with the amino acid sequence shown in SEQ ID NO.1. An expression system suitable for the PmPETase is constructed, recombinase protein with catalytic activity is obtained, and the polyethylene glycol terephthalate hydrolase PmPETase can be used for preparing the polyethylene glycol terephthalate hydrolase PmPETase. The substrate specificity, the catalytic property and the potential plastic degradation capacity of the PET degrading enzyme are comprehensively analyzed, and a new theoretical basis and application reference are provided for development and utilization of the PET degrading enzyme and a high polymer material green treatment technology.

The invention discloses a PET (positron emission tomography) imaging agent, a precursor and a probe for targeting an EphA2 receptor as well as a preparation method and application of the PET imaging agent, the precursor and the probe, and a radioactive probe which is formed by labeling a chelating agent (such as DOTA and NOTA) and a radionuclide (such as 68Ga) by taking bicyclic peptide as a targeting group is specifically combined with the EphA2 receptor highly expressed on the surface of a tumor cell. According to the invention, a conformation limitation strategy is adopted for transforming the peptide probe targeting EphA2 for the first time, the bicyclic peptide radioactive probe with excellent targeting performance and in-vivo imaging effect is obtained, the tumor uptake value is high, and tumor and non-tumor imaging is clear; and successful imaging in a fibrosarcoma model. According to the EphA2 receptor-targeted PET imaging agent provided by the invention, the precursor, namely the probe, has the advantages of simplicity in preparation, good targeting property, excellent imaging effect and the like, can be used for PET imaging diagnosis, prognosis evaluation and targeted therapy guidance of EphA2 positive tumors, and has good clinical value.

The invention relates to a protein consisting of an amino acid sequence in which at least one modification selected from the group consisting of the following [1] to [7] is introduced in the amino acid sequence represented by SEQ ID NO: 1: [1] a modification in which the amino acid residue at a position 103 is substituted with a lysine residue, [2] a modification in which the amino acid residue at a position 76 is substituted with a cysteine residue, [3] a modification in which the amino acid residue at a position 144 is substituted with a cysteine residue, [4] a modification in which the amino acid residue at a position 134 is substituted with a glycine residue, [5] a modification in which the amino acid residue at a position 222 is substituted with a methionine residue, [6] a modification in which the amino acid residue at a position 73 is substituted with a glutamine residue, and [7] a modification in which the amino acid residue at a position 203 is substituted with a threonine residue.

The utility model discloses a tension-adjustable PET bright strip slitting guide device which comprises a bottom plate and a mounting frame, the mounting frame is fixedly mounted at the upper end of the bottom plate, a slitting structure is mounted on one side of the upper end in the mounting frame, and an adjusting guide structure is mounted on the other side in the mounting frame; the adjusting and guiding structure comprises two driving frames, two motors, two lead screws, two moving blocks, an adjusting frame, a plurality of partition plates and a plurality of guiding assemblies. The utility model relates to the technical field of bright strip cutting and conveying, in particular to an adjusting and guiding structure which can adjust the overall height of an adjusting frame and synchronously adjust the tension of a plurality of PET bright strips through the matching of two motors and a lead screw, so that the winding and slitting effects of the PET bright strips are preliminarily ensured, and the production efficiency is improved. And then, according to different winding devices and the winding number, independent tension adjustment can be conducted on the multiple PET bright strips through the multiple guide assemblies, and the slitting and winding effects of the PET bright strips are further guaranteed.

The utility model discloses a six-fold portable mirror which comprises six square PET (Polyethylene Terephthalate) mirrors with the same size, and each two PET mirrors are arranged in parallel in a row; the five groups of hinges are arranged, three groups of hinges are respectively arranged between two parallel PET mirrors, the positions of the hinges are deviated to the front of the PET mirrors, the other two groups of hinges are respectively arranged between one PET mirror in the most front row and one PET mirror in the adjacent middle row, and the other two groups of hinges are respectively arranged between the other PET mirror in the most front row and one PET mirror in the adjacent middle row. The hinge is arranged between one PET mirror in the last row and the other PET mirror in the adjacent middle row, and the position of the hinge is deviated to the mirror back surface of the PET mirror; and the six PET mirrors are folded into the size of the PET mirror with the upward back surface along the direction of the hinges or unfolded into a large-size mirror. According to the six-fold portable mirror, the folding effect is achieved through the small mirror, the hinges and other components, the six-fold portable mirror can be unfolded or folded according to use requirements, and carrying and transportation are convenient. And the magnetic attraction structures are arranged between the adjacent PET mirrors which are not provided with the hinges.

A method for converting post-consumer recycled (PCR) flakes of polyethylene terephthalate (PET) to pellets as part of a container recycling procedure, the method including: adding triphenyl phosphite antioxidant to a reactor at a concentration of 0.05 wt.% to 0.15 wt.%; coating the PCR flakes with the triphenyl phosphite in the reactor; and converting the PCR flakes to the pellets in an extruder after coating the PCR flakes with the triphenyl phosphite to reduce yellowing of the pellets during the conversion.

The invention relates to the technical field of waste polyester recycling and reusing, and discloses a method for depolymerizing copolyester, a depolymerization product and application of the depolymerization product in preparation of the copolyester. The preparation method comprises the following steps: carrying out a depolymerization reaction on copolyester with an average particle size of 0.1-5 cm to obtain a depolymerization solution containing bis (2-hydroxyethyl) terephthalate, a bis (2-hydroxyethyl) terephthalate dimer and cyclohexanedimethanol terephthalate; wherein the copolyester is polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol ester, the water content in the copolyester is less than or equal to 2wt%, and the catalyst is a titanium-containing catalyst. According to the method disclosed by the invention, chemical depolymerization of PETG (or PCTG) copolyester can be realized, the depolymerization rate of the copolyester is improved, and a recyclable polymeric monomer is obtained.

The present application relates to a kind of polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material and its preparation method, the preparation method includes the following steps: polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester material is heat pressed, and the preform of molten state is obtained;The preform of molten state is treated with melt isothermal crystallization and quenching, and sheet material is obtained;Sheet material is treated with foaming, and polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material is obtained.The present application uses melt isothermal crystallization treatment, can improve the melt strength in the foaming process of polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester, strengthens its foaming performance, simultaneously can also be realized by strengthening bubble nucleation and controlling bubble growth to adjust the bubble morphology of foamed material, so polyethylene terephthalate-2,5-furandicarboxylic acid glycol copolyester foamed material with uniform bubble size and controllable foaming ratio can be obtained.

The invention relates to a method for producing polyesters in polycondensation reactions catalyzed by aluminum titanate compounds, barium titanate compounds, calcium titanate compounds, zinc titanate compounds or mixtures of these titanate compounds. The invention also relates to a composition comprising an aluminum titanate compound, a barium titanate compound, a calcium titanate compound, a zinc titanate compound or a mixture of these titanate compounds as a catalyst for the production of polyesters in polycondensation reactions. Furthermore, the invention relates to the use of an aluminum titanate compound, a barium titanate compound, a calcium titanate compound, a zinc titanate compound or a mixture of these titanate compounds as a heterogeneous polycondensation catalyst. The aluminum titanate compound, the barium titanate compound, the calcium titanate compound, the zinc titanate compound or a mixture of these titanate compounds is a non-amorphous mixed oxide of aluminum oxide (and / or barium oxide, and / or calcium oxide, and / or zinc oxide) and titanium oxide. These titanate compounds have been found to be excellent heterogeneous catalysts in polycondensation reactions for the production of polyesters, such as polyethylene terephthalate.

The invention discloses a method for preparing PET (Polyethylene Terephthalate) by polycondensation of high-purity monohydroxyethyl terephthalate under mild conditions, which comprises the following steps of: stirring and reacting monohydroxyethyl terephthalate and ethylene glycol in inert atmosphere at the temperature of 180-230 DEG C for 3-12 hours; and adding a condensation polymerization catalyst into the reaction product, and stirring and reacting for 2-6 hours in an inert atmosphere under the conditions that the temperature is 260-290 DEG C and the vacuum is 40-150 Pa to prepare PET (Polyethylene Terephthalate). According to the preparation method, high-purity monohydroxyethyl terephthalate is used as a polymerization monomer raw material, and PET which meets the current commercially available product standard and is prepared under mild conditions is explored. In addition, based on the current situation that the preparation cost of the high-purity monohydroxyethyl terephthalate is too high, the invention provides a low-cost method for preparing the high-purity monohydroxyethyl terephthalate under a mild condition.

The invention belongs to the technical field of medical biological dressings, and provides a composite dressing with oxygen release and insulin delivery functions and a preparation method thereof.The composite dressing comprises a supporting base layer, a function slow release layer and a protective film layer which are sequentially compounded from bottom to top; the supporting base layer is a medical porous polyurethane film modified by plasma; the functional sustained release layer is composed of hyaluronic acid-chitosan composite gel, oxygen release microspheres and insulin liposome; the protective film layer is a polyethylene terephthalate film of which the surface is provided with a sawtooth edge easy to tear; through an integrated three-layer patch structure, by combining the synergistic effect of PLGA microsphere controlled-release oxygen, liposome low-molecular chitosan insulin delivery and gel matrix, the skin injury microenvironment is effectively improved, inflammation is inhibited, and the healing time is shortened.

A process for producing 1,4-cyclohexanedimethanol by depolymerizing one or more recycled terephthalate-based polyesters or copolyesters via solvolysis with one or more glycols or alcohols and contacting the depolymerization product with an ester hydrogenolysis catalyst and hydrogen to produce a hydrogenolysis product and contacting the hydrogenolysis product with a hydrogenation catalyst and hydrogen to produce 1,4- cyclohexanedimethanol.

A mass spectrometry method according to the present disclosure is a mass spectrometry method in a method for discriminating whether a polyethylene terephthalate fiber contained in a target fiber is a recycled fiber. The mass spectrometry method includes a step of preparing a sample and a step of measuring the sample using matrix-assisted laser desorption / ionization mass spectrometry. The step of preparing the sample has a step of dissolving the target fiber in a first solvent to prepare a solution, a step of adding tetrahydrofuran to the solution to separate the solution into a precipitate and a supernatant, a step of obtaining the supernatant, and a step of preparing a mixed solution containing the supernatant and a matrix on a sample plate.

A PET cat nest facilitating cat hair cleaning comprises a triangular cat nest body, openings are formed in the left side and the right side of the triangular cat nest body, hinges are arranged on plate bodies located at the bottoms of the openings, and rotating plates are arranged on the sides, close to the openings, of the hinges. Sponge pads are arranged at the bottom of the triangular cat nest inner cavity and on the side, close to the triangular cat nest inner cavity, of the rotating plate. An inlet and outlet is formed in the side, close to the bottom, of the center of the front face of the triangular cat nest, a ventilation hole is formed in the center of the back of the triangular cat nest, and a dustproof net is arranged on the ventilation hole. Through the appearance design of the triangular cat house, the plate bodies on the two sides of the triangular cat house are designed in an open mode and matched with the rotating plates designed in a rotating mode, the plate bodies on the left side and the right side of the cat house can rotate to a certain degree, and therefore when a user needs to clean the cat house, the plate bodies can be opened through rotation, and the interior of the cat house is exposed; therefore, the purpose of facilitating cleaning by a user is achieved.

The utility model discloses a PET (Polyethylene Terephthalate) cold drink cup disinfection device which comprises a machine body and a placing box, the interior of the machine body is in sliding connection with the placing box, and a disinfection mechanism is arranged. Water in a water tank is stirred through a stirring rod, so that the heating effect is better, high-temperature steam is sprayed into the machine body through a plurality of gas conveying pipes and a plurality of steam nozzles above, and a temperature detector in the machine body is matched, so that when the internal temperature is detected to start to rise gradually, the heating effect is better; pET cold drink cups are placed in a plurality of holes in the upper portion of a hole plate in the containing box, a plurality of cold drink cups can be placed at a time, at the moment, the containing box is inserted into a sliding groove in the machine body, and after a box door on the surface of the machine body is closed, an internal UV-C lamp is started at the same time to disinfect the cold drink cups above the hole plate; the high-temperature steam is matched with the UV-C lamp, so that the disinfection effect is better.

The invention relates to an ultra-thin dye polaroid, a preparation method and an ultra-thin circular polaroid, and the ultra-thin dye polaroid comprises polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol and a dye dispersed in the polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol in a dissolving mode. According to the invention, dye is dissolved and dispersed in polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol, and the ultrathin dye polaroid is finally obtained through the steps of mixing, extrusion, coating, curtain coating, one-way calendering, stretching and drying. On one hand, a dissolving and dispersing mode is adopted, dye dispersion is more uniform, and the polarization degree and the light transmittance of all parts of the polaroid are guaranteed; on the second aspect, the polaroid does not need to be clamped and fixed by a cellulose triacetate film, so that the thickness of the polaroid can be further reduced; and thirdly, the retarder is compounded on the ultrathin dye polaroid, so that the purpose of manufacturing the ultrathin circular polaroid is achieved.

The utility model relates to the technical field of PET (Polyethylene Terephthalate) slice production and processing, in particular to a PET slice recycling and screening device, which solves the technical problem that PET slices are adhered to each other or adhered to a screen in the vibratory screening process when the PET slices are screened by the existing PET slice recycling and screening device through vibration, and comprises a rack, a screen box is installed above the machine frame, a screen is arranged in the screen box, an air injection assembly is arranged above the screen, the air injection assembly comprises a ventilation pipe and an air nozzle, the air injection assembly is used for guiding air flow into the screen box, in the process of screening PET slices, an air pump works, the air flow is conveyed to the ventilation pipe through an air conveying pipe, and the ventilation pipe is communicated with the air nozzle. The air nozzle connected with the ventilation pipe ejects air flow out, the air nozzle performs horizontal reciprocating motion while spraying air, so that the purpose of blowing the PET slices is achieved, the PET slices are kept in a relatively separated state in the screening process through proper air flow blowing, and adhesion of the PET slices is prevented.

The invention discloses an immunosuppressant transdermal patch and a preparation method thereof, the transdermal patch is provided with a backing layer, an ointment-containing body and a protective layer, the backing layer is a polyester and ethylene-vinyl acetate copolymer film, the ointment-containing body is formed by mixing a main drug tacrolimus, a stabilizer, a matrix, a cross-linking agent and a pressure-sensitive adhesive, and the protective layer is a polyester and ethylene-vinyl acetate copolymer film. The protective layer is a polyethylene glycol terephthalate film, the protective layer is coated with the ointment-containing body, and then the backing layer is pressed and covered on the surface of the ointment-containing body. The immunosuppressant transdermal patch provided by the invention can be adhered to parts such as neck, shoulder, chest, arm memory and the like, can be freely adjusted in use duration according to different illness states, and is safe and free of toxic and side effects. In addition, the transdermal patch disclosed by the invention is good in stickiness, good in permeability, free of irritation and allergy phenomena, good in patient compliance and capable of being used for a long time. Meanwhile, the method has the advantages of low preparation cost, simple and reasonable preparation process and the like, and has wide application prospects.

This invention discloses an anhydrous deoxidizer, comprising, by weight, 10-20 parts of a hydroxyl-terminated polybutadiene-maleic anhydride compound, 10-20 parts of modified zeolite, 15-25 parts of modified silica gel, and 45-55 parts of polyethylene terephthalate. The modified silica gel is prepared from silica gel, sorbitol, bis(3-triethoxysilanepropyl) carbonate, and alumina. The modified zeolite is prepared from zeolite, 1-chloroethylcyclohexyl carbonate, maleimide-L-valine-L-citrulline-p-aminobenzyl alcohol, and N,N-dimethylformamide. The anhydrous deoxidizer provided by this invention exhibits excellent deoxidation performance and efficiency.

The invention discloses a long fiber with a skin-core structure, a long fiber board and application, and belongs to the technical field of polyester fibers.The long fiber with the skin-core structure comprises a polyester skin layer and a polyester core layer, and the polyester skin layer comprises, by weight, 100 parts of modified polyester and 0-5 parts of coloring agent; the modified polyester is obtained by polymerizing a diacid monomer and a polyol monomer in a molar ratio of 1: (1.0-1.5), the diacid monomer comprises one or more of terephthalic acid and isophthalic acid, and the polyol monomer comprises the following components in parts by mole: 70-110 parts of ethylene glycol, 2-10 parts of polyol with 3-6 hydroxyl groups, 5-10 parts of maleimide glycol and 5-10 parts of furan glycol; the polyester core layer is prepared from the following components in parts by weight: 80 to 100 parts of PET (Polyethylene Terephthalate), 10 to 20 parts of PEN (Polyethylene Nitride), 0.1 to 1 part of nucleating agent and 0 to 5 parts of coloring agent. The long fiber with the skin-core structure is low in skin-layer melting point and high in core-layer melting point, and the balance of the low melting point and mechanical properties is considered.

The invention discloses application of a hydrazide nucleating agent containing a long alkyl chain in polyethylene glycol terephthalate, and relates to the technical field of polyethylene glycol terephthalate modification. A long alkyl chain structure in the hydrazide nucleating agent containing the long alkyl chain plays a lubricating role in a polyethylene glycol terephthalate matrix, and regular arrangement of molecular chains of the polyethylene glycol terephthalate matrix is promoted. Meanwhile, rich-NH on a molecular chain of the hydrazide nucleating agent containing the long alkyl chain can generate hydrogen bond interaction with polyethylene glycol terephthalate, so that the interface bonding force between the hydrazide nucleating agent and the polyethylene glycol terephthalate is greatly enhanced, the hydrazide nucleating agent is uniformly dispersed into the polyethylene glycol terephthalate, and the full play of the toughening effect of the hydrazide nucleating agent is ensured.

The balloon catheter is widely used in interventional cardiology. The device named "balloon catheter for aortic annulus enlargement", was modified and adapted for use in open heart surgery, where the aortic annulus is too small. The catheter consists of a polytetrafluoroethylene (PTFE) body, coupled to a polyethylene terephthalate polymer (PET) inflation balloon and a one-way valve. During the procedure, the balloon is inflated inside the aortic ring, allowing it to dilate to facilitate the implantation of adequate prostheses. The balloons have pre-determined sizes, corresponding to those of the prostheses available. This method avoids the need for adjuvant techniques, such as sectioning and reconstitution using biological or inorganic materials. The use of the catheter balloon simplifying the procedure and significantly reduces the costs and risks associated with this complex surgery. The implantation of properly sized prostheses provides numerous benefits to the patient, both in the short and long term.

The invention relates to the technical field of polyester waste recycling, in particular to an acid-base double-site metal-free catalyst as well as a preparation method and application thereof. The acid-base double-site metal-free catalyst provided by the invention is suitable for oxidative depolymerization of polyester, especially polyethylene glycol terephthalate, is low in catalyst dosage, and has the characteristics of excellent reaction kinetics performance, environmental protection property and recyclability. When the temperature is 180 DEG C and the mass ratio of the PET waste to the catalyst is 100: 1, the reaction is carried out for 30 minutes, the PET degradation rate is 99.97%, the ethylene glycol yield is 91.53%, and the dimethyl terephthalate yield is 90.62%. The mass ratio of the PET waste to the catalyst is further increased to 150: 1, and the PET degradation rate is still kept at 97.68%, so that the acid-base double-site metal-free catalyst provided by the invention has excellent depolymerization performance under the condition of high PET loading capacity.

A recombinant actinobacterium which can metabolise polyethylene terephthalate (PET), a derivative thereof and / or a monomer thereof as a carbon source, wherein the actinobacterium in its native / wildtype or unactivated state cannot metabolise PET, a derivative thereof and / or a monomer thereof as a carbon source. Also provided are uses of streptomyces antibiotic regulatory protein (SARP) regulators to activate or enhance metabolism of PET, a derivative thereof and / or a monomer thereof as a carbon source in an actinobacterium; a method of degrading PET, a derivative thereof and / or a monomer thereof; and a method of determining if an actinobacterium can metabolise PET, a derivative thereof and / or a monomer thereof as a carbon source.

The application discloses a cutinase mutant and application thereof to efficient degradation of PET. The amino acid sequence of the cutinase mutant is shown in SEQ ID NO. 2, and is obtained by replacing phenylalanine at the 239th amino acid in the amino acid sequence of a wild-type cutinase shown in SEQ ID NO. 1 with alanine. The cutinase mutant is expressed in E. coli, and compared with the wild-type enzyme, the activity of the mutant enzyme is increased in stability, the catalytic efficiency is improved, and the yield of a PET plastic (polyethylene terephthalate, PET) degradation product is increased by 42.6 times. The improved cutinase mutant improves the PET degradation efficiency, reduces the production cost, and is more suitable for industrial application.