323 results about "Polyethylene terephtalate" patented technology

The invention discloses a method for preparing a modified PHA composite material by using a twin-screw extruder and application of the modified PHA composite material. The method comprises the following steps: carrying out in-situ melt blending on polyhydroxyalkanoate (PHA), poly (butylene adipate terephthalate)-poly (butylene adipate terephthalate) (PBAT), polyvinyl alcohol (PVOH) and chain extenders in a twin-screw extruder, so that the chain extenders such as polyfunctional group epoxy or isocyanate react with molecular terminal groups of the PHA, the PBAT and the PVOH to form a partially crosslinked or grafted structure; therefore, the compatibility is enhanced, the thermal stability is improved, and the barrier property is remarkably improved. Experiments prove that the obtained modified PHA composite material has the characteristics of high strength, high elongation, excellent water and oxygen resistance and biodegradability, and meets the strict requirements of multiple fields such as food packaging, agricultural plastic mulching films, medical consumables and the like on mechanical properties and barrier properties. The preparation method is simple, convenient and efficient, and large-scale continuous production can be achieved on existing double-screw extrusion equipment.

The invention discloses degradable coated paper and a preparation method thereof, and belongs to the field of high polymer materials. Aiming at the problem of single function of the existing coated paper, the invention provides the degradable coated paper, the degradable coated paper comprises backing paper and a coated layer, and the coated layer comprises the following components in parts by weight: 50-80 parts of polylactic acid and 10-25 parts of poly (ethylene terephthalate) succinate; the plastic is prepared from the following components in parts by weight: 1-5 parts of biodegradable chitosan, 10-20 parts of modified talcum powder, 0.3-1.0 part of a plasticizer, 0.2-1.0 part of a lubricant, 0.2-0.5 part of an antioxidant and 0.2-0.5 part of a compatilizer. The antibacterial purpose is achieved by selecting the degradable chitosan, and meanwhile the mechanical performance of the coated paper is not affected; the purposes of heat preservation, cost reduction and efficiency improvement are achieved through the modified talcum powder, so that the finally prepared degradable coated paper has multiple functions of degradability, heat preservation and antibiosis; meanwhile, all the used raw materials are biodegradable, so that the environment-friendly significance is higher. The operation is simple, the convenience and the efficiency are higher, and the use prospect is higher.

Disclosed in the present invention are a high-strength polylactic acid material, a preparation method therefor, and use thereof, belonging to the technical field of macromolecular materials. The high-strength polylactic acid material comprises the following components in parts by weight: 80-90 parts of polylactic acid, 10-20 parts of polybutylene adipate terephthalate, 1-5 parts of a nucleating agent, and 2-5 parts of a compatibilizing agent. The mesh number of the nucleating agent is 1500-2500 mesh; the compatibilizing agent is polycaprolactone, and the intrinsic viscosity thereof is 1.0-3.0 dL / g. The present invention lowers the melting temperature and shortens the melting time of PLA and PBAT, reduces the negative impact of polymer degradation and aging on mechanical properties, produces a heterogeneous nucleation effect, and performs the function of a crystallization nucleus in the cooling crystallization stage, improving crystallization speed and crystallinity, while causing the crystalline phase structure to tend toward a spherulitic state, improving the tensile strength of the polylactic acid material.

The invention relates to the technical field of packaging bags, and discloses a moisture-proof medical packaging bag material and a preparation method thereof. The moisture-proof medical packaging bag material comprises a paper layer and a plastic layer, the paper layer comprises modified kraft paper, and the plastic layer comprises the following raw materials in parts by weight: 70-100 parts of polybutylene terephthalate adipate, 30-50 parts of polypropylene carbonate, 5-7 parts of modified mica and 1.5-3 parts of cellulose acetate oleate. The moisture-proof medical packaging bag material prepared by the invention has good water resistance and mechanical properties, also has good degradability, and has a good application prospect.

The present application relates to the technical field of bio-based polymer material, and more particularly to a full bio-based PBAT-PLA copolymer, a preparation method and an application thereof, which is prepared by melt mixing bio-based polybutylene adipate terephthalate, bio-based polylactic acid and bio-based multi-epoxy chain extender through a twin-screw extruder, so that the tensile strength of the full bio-based PBAT-PLA copolymer is 31.5-44.3 MPa, and the elongation at break is 85-498%. The bio-based multi-epoxy chain extender prepared by specific selection can simultaneously improve the tensile strength and elongation at break of the full bio-based PBAT-PLA copolymer, and solve the technical problems of poor compatibility of traditional bio-based polylactic acid and non-bio-based polybutylene adipate terephthalate, and the technical problem that the addition of existing chain extenders cannot simultaneously improve the tensile strength and elongation at break of the copolymer.

The biodegradable PBAT / bamboo charcoal master batch is prepared from the following raw materials in parts by mass: 100 parts of poly (butylene adipate-co-terephthalate) (PBAT), 20 to 30 parts of poly (butylene succinate), 10 to 30 parts of modified bamboo charcoal powder and 0.2 to 0.4 part of chain extender, the modified bamboo charcoal powder is obtained by sequentially carrying out persulfate treatment, microwave-assisted reaction and grafting agent modification on bamboo charcoal powder, and the grafting agent comprises polybasic acid and an epoxy compound. The bamboo charcoal powder is subjected to grafting modification, so that the interfacial compatibility with the PBAT base material and the matrix dispersity are remarkably improved, and the mechanical property of the composite material is improved. The modifier compounded according to a specific ratio improves the damp-heat aging resistance of the master batch composite material.

The present invention discloses a method for preparing a modified PHA composite material using a twin-screw extruder and its application. The method is carried out by in-situ melt blending of polyhydroxyalkanoate PHA, polybutylene terephthalate-adipate PBAT, polyvinyl alcohol PVOH and a chain extender in a twin-screw extruder, so that a multifunctional epoxy or isocyanate chain extender reacts with the terminal groups of PHA, PBAT and PVOH molecules to form a partially cross-linked or grafted structure, thereby achieving enhanced compatibility, improved thermal stability and significant improvement in barrier properties. Experiments have shown that the modified PHA composite material obtained by the present invention has high strength, high elongation, excellent water and oxygen barrier properties and biodegradable properties, and meets the stringent requirements for mechanical properties and barrier properties in multiple fields such as food packaging, agricultural mulch and medical consumables. The preparation method of the present invention is simple and efficient, and can be used for large-scale continuous production on existing twin-screw extrusion equipment.

The invention provides a high-performance thermoplastic starch-based TPS / PBAT blended plastic and a preparation method thereof. The preparation method comprises the following steps: preparing pre-plasticized starch, carrying out melt blending on the obtained pre-plasticized starch TPS, poly (butylene adipate-co-butylene adipate) PBAT, a grafting agent and an initiator, cooling, and drying to obtain a grafting material; and putting the grafted material and a cross-linking agent into an internal mixer for melt blending, cooling and drying to obtain the high-performance thermoplastic starch-based blended plastic TPS / PBAT. The method is suitable for industrial large-scale mass production and recycling treatment, the recycling treatment can be realized by directly adopting plastic processing methods such as an internal mixer and an extruder, and the high-performance thermoplastic starch-based blended plastic can be obtained again under the condition that the molecular chain part is degraded.

The invention belongs to the technical field of packaging materials, and particularly relates to a composite film paper material and a preparation method thereof. The composite film paper material comprises a composite film layer and a paper layer, the composite film layer is prepared from the following components in parts by weight: 60 to 70 parts of polylactic acid, 20 to 30 parts of polybutylene terephthalate adipate, 5 to 8 parts of polyether polyol, 5 to 8 parts of esterified hydrophobic fumed silica and 3 to 5 parts of quinoline; the preparation process of the esterified hydrophobic fumed silica comprises the following steps: stirring fumed silica and acetyl chloride, and drying to obtain the esterified hydrophobic fumed silica. The esterified hydrophobic fumed silica, the polylactic acid, the quinoline and the polyether polyol are mixed according to a scientific proportion, and the barrier property of the composite film paper material is remarkably improved by utilizing the hydrophobicity of the esterified hydrophobic fumed silica and a compact structure formed among the components, and meanwhile, the mechanical property of the composite film paper material is not influenced.

An asphalt modifier includes bitumen, polyolefin particles, and one or more alkyl terephthalamides. Preparing an asphalt modifier includes combining one or more alkyl terephthalamides, polyolefin particles, and bitumen, and dispersing the polyolefin particles in the bitumen to yield the asphalt modifier. Digesting polyethylene terephthalate includes combining polyethylene terephthalate with an alkylamine or carboxyalkylamine to yield a reaction mixture, and heating the reaction mixture to a temperature between about 20° C. and about 300° C. to yield an alkyl terephthalamide.

The invention discloses a halogen-free flame-retardant regenerated PET material for steel coil packaging and a preparation method thereof, and belongs to the technical field of regenerated PET materials, and the halogen-free flame-retardant regenerated PET material for steel coil packaging is characterized by comprising the following raw materials in parts by weight: 100 parts of regenerated PET, 5-10 parts of POE-g-GMA, 4-8 parts of a flexibilizer, 1-3 parts of polyethylene glycol terephthalate, 1-3 parts of a flame retardant, 1-3 parts of an antioxidant, 1-3 parts of a lubricant, and 1-3 parts of a lubricant. The regenerated PET material is prepared from the following components in parts by weight: 15-20 parts of 1, 4-cyclohexanedimethanol ester, 3-7 parts of a flame retardant, 1-3 parts of a stabilizer and 0.3-0.5 part of an antioxidant, so that the effect of improving the impact resistance of the regenerated PET material is achieved.

The application belongs to the technical field of plastics, and particularly relates to a degradable antibacterial plastic packaging bag and a preparation method thereof. The degradable antibacterial plastic packaging bag comprises the following raw materials in parts by weight: polycaprolactone 70-90 parts; polybutylene adipate terephthalate 20-40 parts; Cr and Cu co-modified ZIF-8 5-20 parts; and cerium oxide tannic acid material 2-6 parts. The Cr and Cu co-modified ZIF-8 synergistically improves the antibacterial performance of the packaging bag, and the addition of the cerium oxide tannic acid material further improves the antibacterial performance of the packaging bag. Moreover, the degradable antibacterial plastic packaging bag prepared by the application has excellent mechanical properties.

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

[Problem] To provide a method capable of producing a monocyclic aromatic hydrocarbon such as benzene or xylene effective as a base raw material, with a naphtha raw material containing renewable naphtha. [Solution] A method for producing at least one monocyclic aromatic hydrocarbon of benzene or xylene with a naphtha raw material containing renewable naphtha, the method including step (A-1) of pyrolyzing the naphtha raw material in the presence of water vapor, to produce and separate toluene, and step (A-2) of subjecting toluene to disproportionation reaction or transalkylation reaction, to produce and separate at least one monocyclic aromatic hydrocarbon of benzene or xylene.

A first aspect of the invention relates to a process for recycling of a colored polymeric material, wherein the colored polymeric material comprises (i) a polyalkylene terephthalate based polymer, (ii) a colorant and optionally (iii) a second polymer different from the polyalkylene terephthalate based polymer of (i) and optionally (iv) a third polymer different from the polyalkylene terephthalate based polymer of (i) and different from the second polymer of (iii), the process comprising (a) providing a colored polymeric material and a solvent system comprising gamma valerolactone (GVL); (b) contacting the colored polymeric material provided in (a) with the solvent system comprising GVL provided in (a) under conditions allowing for colorant removal but not allowing for dissolution of the polyalkylene terephthalate based polymer, thereby obtaining a solvent system, which is enriched in colorant compared to the solvent system provided, and a polymeric material, which is depleted in colorant compared to the colored polymeric material provided in (a); (c) depolymerisation or transesterification of the polymeric material, which is depleted in colorant obtained in (b); thereby obtaining monomers and / or oligomers or transesterification products. In a second aspect, the invention relates to a monomer, oligomer or transesterification product of a polyalkylene terephthalate based polymer obtained or obtainable by the process of the first aspect. A third aspect relates to a process comprising converting, preferably polymerizing, the monomers, oligomers or transesterification products of a polyalkylene terephthalate based polymer obtained from the process of the first aspect to obtain one or more polymer or polymer product. A fourth aspect relates to a process comprising converting the separated second polymer (iii) and / or the separated third polymer (iv) obtainable by or obtained from the process of the first aspect to obtain one or more monomer, polymer or polymer product.

The invention belongs to the technical field of degradable packaging materials, and discloses a preparation method of a degradable preservative film. The anti-fog antibacterial plastic is prepared from the following raw materials in parts by weight: 40 to 45 parts of poly (butylene adipate-co-terephthalate) (PBAT), 8 to 12 parts of polylactic acid (PLA), 28 to 32 parts of modified structural starch, 4 to 6 parts of poly (butylene carbonate) (PBC), 4 to 6 parts of talcum powder, 0.4 to 0.6 part of aluminate, 0.8 to 1.2 parts of a composite antibacterial agent and 2.5 to 3.5 parts of anti-fog master batch. The invention aims to overcome the defects in the prior art, and provides the degradable preservative film and the preparation method thereof, the preservative film not only has good degradability and mechanical properties, but also has excellent antibacterial and antifogging effects, and the preparation process is simple and easy for industrial production.

The invention discloses a degradable high-strength plastic bag and a preparation method thereof, and relates to the technical field of plastic bag preparation. The degradable high-strength plastic bag at least comprises the following raw materials in parts by mass: 40-60 parts of polylactic acid, 20-35 parts of poly (adipic acid) / butylene terephthalate, 5-15 parts of modified nano calcium carbonate, 3-8 parts of modified wood fibers, 6-8 parts of chitosan grafted polyglycidyl methacrylate nanoparticles, 0.5-2 parts of a lubricant, 0.3-1 part of an antioxidant and 2-5 parts of a degradation accelerator. And 0.5 to 1.5 parts of an ultraviolet stabilizer. According to the degradable high-strength plastic bag prepared by the preparation method disclosed by the invention, the polylactic acid and the poly (butylene adipate-co-terephthalate) are used as base materials, the modified nano calcium carbonate and the modified fibers are used as fillers, and the chitosan grafted polyglycidyl methacrylate nanoparticles are used as a compatilizer, so that the balance of high strength and degradability is realized; the prepared degradable high-strength plastic bag can be used as a high-performance flexible packaging material.

Methods and systems for transferring an alkali metal film, for example, a lithium film or a sodium film, from a flexible carrier substrate, for example, a polyethylene terephthalate (PET) substrate onto a metallic-containing substrate, for example, a copper foil, is provided. The methods and systems utilize atmospheric plasma in combination within a roll-to-roll process to facilitate the transfer of the alkali metal film while etching away residue from a release layer or reaction layer formed during high-temperature deposition of the lithium film. The resulting pristine lithium surface can then be passivated. The methods and systems are especially useful for applications in lithium-ion batteries and other energy storage devices.

The present invention relates in a first aspect to a process for recovery of a polyethylene terephthalate (based polymer from a polymeric material. A second aspect of the invention is directed to polyalkylene terephthalate based polymer obtained or obtainable from the process of the first aspect, and a third aspect relates to the use of the polyalkylene terephthalate based polymer of the second aspect for textile applications, fiber applications, packaging applications, plastic applications, automotive applications, electronic applications, preferably for the production of food packaging, beverage packaging, clothing, foot wear, wire, cable, wherein preferably for textile applications, fiber applications, packaging applications, plastic applications, more preferably for the production of food packaging, beverage packaging, clothing and foot wear. A fourth aspect of the invention is related to a method for preparing a product comprising (I) providing polyalkylene terephthalate based polymer of the second aspect; and (II) preparing a textile, a fiber, a packaging, a plastic, an automotive part, an electronic part from the polyalkylene terephthalate based polymer provided in (I). A fifth aspect is related to a process, preferably according to the first aspect, comprising the further step of converting a residue obtainable by or obtained by the process according to the first aspect to obtain one or more monomer(s). In a sixth aspect, the invention is related to a process comprising conversion of a residue obtainable by or obtained by the process according to the first aspect to obtain one or more monomer, polymer or polymer product.

The invention belongs to the technical field of preparation of molecular materials and adhesive tapes, and discloses a degradable mylar adhesive tape and a preparation method thereof, the degradable mylar adhesive tape comprises a degradable base material layer and a degradable adhesive layer; the degradable base material layer is prepared from the following raw materials in parts by mass: 25-35 parts of poly (butylene succinate) (PBS), 20-30 parts of polylactic acid (PLA), 10-15 parts of polycaprolactone (PCL), 8-12 parts of modified bamboo fiber powder, 3-5 parts of a compatibilizer and 0.5-1 part of an antioxidant; the degradable adhesive layer is prepared from the following raw materials in parts by mass: 40 to 50 parts of a modified starch-based adhesive, 15 to 25 parts of poly (butylene adipate-co-terephthalate) (PBAT), 10 to 15 parts of polyhydroxyalkanoate (PHA), 5 to 8 parts of sodium alginate-chitosan composite gel, 5 to 8 parts of an epoxypropane modifier, 1 to 2 parts of a cross-linking agent and 0.3 to 0.5 part of a de-foaming agent; by optimizing the raw material composition and the preparation process of the base material and the adhesive, the full-life-cycle degradability of the adhesive tape is realized, and meanwhile, excellent mechanical properties, insulativity and temperature resistance are ensured.

Described is a method of preparing bis (2-hydroxyethyl) terephthalate (BHET) monomer crystals comprising the steps of providing a mixture of BHET monomers and oligomers thereof, a carrier liquid, and impurities; providing BHET seed crystals in the mixture; forming BHET monomer crystals from the mixture comprising the BHET seed crystals, thereby obtaining BHET monomer crystals in a mother liquor; and separating the BHET monomer crystals from the mother liquor; wherein the powder X-ray diffraction spectrum of the BHET seed crystals at least has characteristic intensity peaks at 2Ɵ about equal to 10.7°, 14.4°, 18.9° and 21.6°, where Ɵ is the angle of diffraction, and / or the IR spectrum of the BHET seed crystals at least has characteristic absorption peaks at λ about equal to 3260 cm-1 and 897 cm-1, where λ is the ordinary wavenumber. The obtained BHET monomer crystals have superior filtration properties. Also described is a method of preparing the BHET seed crystals, a method of depolymerizing a terephthalate polymer using the BHET seed crystals, as well as a corresponding reactor system for depolymerizing said terephthalate polymer.

The present application provides compositions, methods, and dispensers for topical delivery of ophthalmological active pharmaceutical ingredients (APIs). In one example, a composition is provided comprising an active pharmaceutical ingredient soluble in MCT wherein the API is not atropine or a salt thereof; a medium chain triglyceride (MCT); and a semi-fluorinated alkane compound. In another example, a nano-emulsion is provided comprising about an active pharmaceutical ingredient soluble in MCT; a medium chain triglyceride (MCT); and a semi-fluorinated alkane compound, wherein the nano-emulsion has a droplet particle size D90 of less than about 100 nm. 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 an ocular condition in a subject comprising administering the compositions or nano-emulsions to an eye of the subject. The present application also provides compositions and methods for treating ophthalmological conditions such as presbyopia and glaucoma. The compositions can comprise a muscarinic cholinergic receptor agonist and a semi-fluorinated alkane compound; or can comprise a muscarinic cholinergic receptor agonist, a semi-fluorinated alkane compound, and an organic cosolvent. The compositions can confer chemical stability of the muscarinic cholinergic receptor agonist.

The present application relates to the field of batteries and specifically discloses a lithium battery sealing material and a preparation method thereof. The lithium battery sealing material comprises the following raw materials in parts by weight: 100-150 parts of nylon, 5-15 parts of maleic anhydride grafted polypropylene, 10-20 parts of rosin glycerol ester, 5-10 parts of poly(trimethylene terephthalate), 5-15 parts of filler, 0.5-1 part of antioxidant, and 0.2-0.5 parts of dispersant. The preparation method comprises the following steps: uniformly mixing nylon, poly(trimethylene terephthalate), and maleic anhydride grafted polypropylene to obtain a primary mixture; uniformly mixing the filler and rosin glycerol ester, and then uniformly mixing the filler and the rosin glycerol ester with the primary mixture to obtain a mixture; adding the antioxidant and the dispersant to the mixture, stirring evenly, and extruding to obtain a finished product. The hygroscopicity of a button battery sealing ring is reduced, and the sealing ring is ensured to have high mechanical strength, good sealing effect, and long service life, thereby extending the service life of the button battery.

The present invention discloses a degradable plastic, a container made from the plastic, and a preparation method thereof, belonging to the technical field of degradable plastic container processing. The preparation method of the degradable plastic comprises the following steps: mixing polybutylene terephthalate-adipate resin, starch, composite aerogel, modified corn straw fiber, a lubricant, and a plasticizer, stirring uniformly to obtain a mixture; and extruding and granulating the mixture to obtain a degradable plastic. The composite aerogel has gas barrier properties, improving the gas barrier properties of the polybutylene terephthalate-adipate plastic container. The composite aerogel also has high mechanical strength, preventing the leakage of modified ultrafine coal powder caused by the poor mechanical properties of the sericin aerogel, causing the modified ultrafine coal powder to migrate and precipitate in the plastic, affecting the degradation performance of the plastic.

The invention belongs to the technical field of plastics, and particularly relates to a biodegradable antibacterial plastic bag and a preparation method thereof. The material comprises the following raw materials in parts by weight: 20-40 parts of polylactic acid; 60 to 80 parts of polycaprolactone; 50 to 70 parts of poly (butylene adipate-co-terephthalate); 2-6 parts of a carbonized polymer; and 3 to 5 parts of the SrWO4-coated Cu and Zn-TCPP composite material. The carbonized polymer is prepared by adopting a carbon source through a hydrothermal method, the carbonized polymer plays a good role in inhibiting growth of bacteria, the antibacterial performance and mechanical performance of the plastic are improved by preparing tungstate and matching with the MOF material, and the prepared antibacterial plastic bag is excellent in performance, wide in market application and good in prospect.

The invention relates to the technical field of polyester composite materials, in particular to a reinforced flame-retardant polyester composite material for a baking all-in-one machine shell and a preparation method of the reinforced flame-retardant polyester composite material for the baking all-in-one machine shell. The polybutylene terephthalate and the polybutylene terephthalate cooperate to obtain higher heat deformation temperature, heat resistance and high strength, and the polybutylene terephthalate has better fatigue resistance and dimensional stability and smaller creep deformation; the graft modified thermoplastic polyester elastomer is added, the special thermosensitive hydrophobicity of the graft modified thermoplastic polyester elastomer and the toughening property of the thermoplastic polyester elastomer are utilized, and the graft modified thermoplastic polyester elastomer, the toughening agent and the antioxidant have a synergistic effect, so that the hydrolysis resistance, the high-temperature and high-humidity resistance, the weather resistance, the high-low temperature impact toughness and the low shrinkage rate of the polyester composite material are improved; the added brominated flame retardant and halogen-free flame retardant have a synergistic flame retardant effect, so that the flame retardant requirement of the material can be met; the glass fibers have hydrolysis-resistant and low-warping effects, low shrinkage can promote the structure flatness of the product, and the glass fibers are particularly suitable for producing the baking all-in-one machine shell.

Processes and systems for producing recycled content polyethylene terephthalate (r-PET) are provided. Integration of chemical recycling facilities with PET production facilities reduces energy consumption and helps minimize adverse environmental impacts, while providing valuable end products having up to 100 percent recycled content. Additionally, processes and systems described herein may provide high IV, crystalline PET based on dimethyl terephthalate, which can exhibit desirable properties during molding and other end use applications.

The invention discloses a low-cost high-performance full-biodegradable polylactic acid-based heat-shrinkable film which is prepared from the following raw materials in parts by weight: 10-30 parts of polylactic resin, 70-90 parts of poly (butylene adipate-co-terephthalate) resin, 0.5-5 parts of a chain extension compatibilizer, 0.1-1 part of an antioxidant, 1-3 parts of a lubricant, 5-30 parts of a modified inorganic filler and 1-5 parts of an ultraviolet radiation aid, the invention also discloses a preparation method of the thermal shrinkage film. According to the thermal shrinkage film, the plastic component can be completely biodegraded in the natural environment, serious white pollution caused by the fact that the plastic is discarded into the natural environment is avoided, meanwhile, the lactide raw material part for synthesizing the PLA resin comes from grain processing by-products, and value-added utilization of the grain processing by-products is facilitated.

The invention discloses a full-biodegradable mulching film capable of relieving microplastic release harm. The full-biodegradable mulching film is prepared from the following components in parts by weight: 100 to 150 parts of poly (butylene adipate-co-terephthalate); 0.5 to 1.5 parts of an ultraviolet light absorber; 0.5 to 0.6 part of an antioxidant; 0.5 to 0.6 part of a lubricant; and 2-8 parts of modified charcoal. The method comprises the following steps: pretreating biochar with a KOH solution to obtain pretreated biochar; adding the pretreated biochar into a glacial acetic acid solution of chitosan oligosaccharide, stirring at room temperature, dropwise adding a sodium citrate solution, standing at low temperature, centrifuging, washing, and drying in vacuum to obtain chitosan oligosaccharide grafted biochar; and adding the chitosan oligosaccharide grafted biochar into carbon black, and mixing to obtain the modified biochar. The modified biochar prepared by the method can replace carbon black to prepare a full-biodegradable mulching film with higher strength and water vapor permeability; after the mulching film is degraded, the biochar adsorbs the degraded micro-plastics, so that the damage of the micro-plastics to crops is reduced.

The present invention discloses a method for preparing a modified starch composite material having both thermoplasticity and cross-linking properties, and belongs to the technical field of polymer material modification. First, triphenylmethane triisocyanate is mixed with corn starch to react and prepare cross-linked starch; secondly, N, N-dimethylformamide is mixed with sorbitol and then a composite plasticizer is prepared, and after mixing with the cross-linked starch, melt extrusion is performed to obtain thermoplastic cross-linked starch; finally, thermoplastic cross-linked starch and polybutylene terephthalate adipate are melt-extruded to obtain a modified starch composite material having both thermoplasticity and cross-linking properties. The modified starch composite material having both thermoplasticity and cross-linking properties prepared by the present invention has high strength and high toughness, with tensile strength increased from 8.23Mpa to 22.53Mpa, flexural strength increased from 2.14Mpa to 4.26Mpa, and elongation at break increased from 382% to 650%.