92 results about "Medium molecular weight" patented technology

The invention discloses aureobasidium pullulans, application thereof and a method for producing medium-molecular-weight pullulan, and belongs to the technical field of microorganisms. The aureobasidium pullulans disclosed by the invention is aureobasidium pullulans SYCY-018, the strain is preserved in the general microbiological center of the China Committee for Culture Collection of Microorganisms on December 26, 2022, and the preservation number is CGMCC (China General Microbiological Culture Collection Center) NO.40467. According to the aureobasidium pullulans SYCY-018, the aureobasidium pullulans SYCY-018 and the aureobasidium pullulans The aureobasidium pullulans SYCY-018 is inoculated into a fermentation medium for fermentation to produce the pullulan, the yield of the medium-molecular-weight pullulan reaches up to 150 g / L or above, meanwhile, good hereditary stability and high temperature resistance are achieved, the yield of the pullulan can still be higher than 130 g / L even at the high temperature of 40 DEG C, and the aureobasidium pullulans SYCY-018 is suitable for industrial production.

The invention provides a preparation method and application of medical grade agarose with different molecular weights, and belongs to the technical field of biomedical materials. According to the invention, the crude agarose product is treated by DMSO, EDTA-Na2 and DEAE-cellulose, and then the acid concentration, the acid treatment temperature, the acid treatment time and the like in the acid treatment stage are finely regulated, so that the medical-grade agarose with medium-high molecular weight (3000-100000), medium molecular weight (3000-3000) and low molecular weight (1t, 3000) is successfully prepared. The medium-high molecular weight and medium molecular weight medical grade agarose provided by the invention has excellent gel performance, adjustable mechanical strength and injection performance, and is suitable for the fields of skin implants, gel dressings, tissue engineering and the like; the low-molecular-weight medical grade agarose shows good water solubility, fluidity and oxidation resistance, and has significant application potential in the fields of medical skin care products and functional dressings.

The invention discloses a method for producing multimodal polyethylene through series connection of multiple reactors, and belongs to the field of olefin polymerization. The low-molecular-weight or medium-molecular-weight ethylene polymer is produced through polymerization in the first reactor, the obtained product enters the intermediate treatment unit to remove hydrogen, and then part of the product is shunted to enter the second reactor to be mixed with the ultra-high-molecular-weight ethylene polymer produced through ethylene polymerization in the second reactor; all polymers of the second reactor are returned to the intermediate treatment unit, and the rest products after hydrogen removal enter a third reactor and are mixed with high-molecular-weight ethylene polymers generated by copolymerization of ethylene and comonomers in the third reactor to generate multimodal polyethylene. The multimodal polyethylene produced by the method is wide in molecular weight distribution, and the molecular weight of ultra-high molecular weight polyethylene is flexible to regulate and control. According to the invention, material circulation between the third reactor and the second reactor is adopted, molecular chain-level mixing among the components is achieved, the compatibility is good, and the mechanical property is more excellent.

The invention relates to the technical field of preparation of sealing materials, in particular to a photovoltaic module sealant with ultralow water vapor transmittance and a preparation method of the photovoltaic module sealant. The invention discloses a solar cell panel which at least comprises the following components in parts by weight: 4-10 parts of polymer rubber or resin, 25-30 parts of medium molecular weight polyisobutene, 7-15 parts of silane modified resin, 15-20 parts of reinforcing filler, 30-40 parts of incremental filler, 3-8 parts of a drying agent, 0.3-1 part of an antioxidant and 0.3-1 part of an ultraviolet stabilizer. Meanwhile, the anti-aging performance and the processing performance are excellent, so that the photoelectric conversion efficiency of the solar cell is improved, and the service life of the solar cell is prolonged.

The present invention discloses a monodisperse lignin colloidal sphere, a preparation method, and an application as a structural color material. The method comprises the following steps: first, lignin is steamed under alkaline conditions, and then ultrafiltration is performed to remove low-molecular-weight and high-molecular-weight lignin to obtain a uniform medium-molecular-weight lignin, which is then reacted with a glycidyl ether compound to further regulate polar groups such as hydroxyl groups, and then short-chain alcohols are used to separate alcohol-insoluble lignin. The alcohol-insoluble lignin is dissolved in an organic solvent-water mixed solvent, water is added dropwise to cause phase separation, and finally, centrifugal sedimentation is performed to obtain monodisperse lignin colloidal spheres. The preparation process of the method of the present invention is green and environmentally friendly, the organic solvents used can be recycled and reused, and the product yield reaches more than 70%. The obtained monodisperse lignin colloidal spheres can be used as a structural color material.

The invention discloses novel organic silicon modified polyester resin and a preparation method thereof. The novel organic silicon modified polyester resin is prepared from phenyl trichlorosilane, propyl trichlorosilane, medium molecular weight polyester resin, a catalyst, an organic solvent and other raw materials. The phenyl propyl silicon resin prepolymer prepared from the phenyl trichlorosilane and the propyl trichlorosilane with the preferable dosage is subjected to graft copolymerization with the medium-molecular-weight polyester resin to obtain the novel organic silicon modified polyester resin with excellent performance. The synthesized novel organic silicon modified polyester resin has good mechanical properties, good electrical insulation properties, good heat resistance, good weather resistance and the like, and has very good technical effects. The coating can be used for insulating and flame-retardant coating of a new energy electric vehicle battery.

The present invention discloses an elastic anti-corrosion adhesive, an elastic anti-corrosion adhesive tape and a preparation method thereof, which belongs to the technical field of anti-corrosion adhesive tape materials, comprising: by weight, 5 to 8 parts of elastic rubber, 3 to 5 parts of high molecular weight polyisobutylene, 20 to 35 parts of medium molecular weight polyisobutylene, 5 to 10 parts of elastic fiber, 40 to 60 parts of inorganic powder and 1 to 5 parts of anti-aging agent. The elastic anti-corrosion adhesive provided by the present invention possesses excellent extensibility and resilience. The extensibility thereof allows it to be applied to irregular surfaces, forming a tight bond with the substrate surface, and reducing voids. And the resilience thereof gives the anti-corrosion adhesive self-tightening properties, promoting its penetration into the microscopic surface of the substrate, effectively isolating air and moisture, thereby enhancing its corrosion resistance.

The invention relates to the technical field of coatings, and discloses a high-filling super-curing floating coating in the field of rail transit, and the floating coating comprises nano titanium dioxide-based hydroxyl-terminated hyperbranched polyester, medium molecular weight acrylic resin, a blocked high-functionality polyisocyanate cross-linking agent, a dispersing agent and the like. A coating obtained by adopting a super-curing system of nano titanium dioxide-based hydroxyl-terminated hyperbranched polyester and an isocyanate crosslinking agent is high in crosslinking density and good in toughness, coating resistance such as water resistance and moisture resistance is remarkably improved, a higher-level protection effect on putty is achieved, particularly, the water resistance can reach 48 h, and the water resistance can reach 48 h. Meanwhile, the floating coating is quick to dry and easy to construct, has high gloss, fullness and leveling property, can be widely applied to the field of rail transit by matching with high-performance putty and finish paint, and realizes periodic performance guarantee of the whole life.

The invention belongs to the field of biomass-based functional materials, relates to a difunctional coating based on enzymolysis modified cassava starch as well as a preparation method and application of the difunctional coating, and innovatively solves the technical problem that a single coating gives consideration to oil prevention and water absorption through a synergistic technical path of pretreatment and composite enzymolysis. The core mechanism is as follows: the starch particle structure is destroyed through pretreatment, and the degradation degree of starch is accurately controlled through the synergistic effect of alpha-amylase and saccharifying enzyme, so that an unexpected technical effect is achieved, and an enzymolysis product with a film-forming skeleton (medium molecular weight dextrin) and a hydrophilic unit (small molecular saccharide) is formed; meanwhile, a compact and continuous network structure can be formed by a film-forming framework, and grease permeation is blocked; and the hydrophilic unit endows the coating with a rapid capillary water absorption effect.

The invention provides a special material for a large hollow container and a preparation method thereof, the special material is prepared by adopting a kettle type slurry polymerization process with three kettles connected in series, a catalyst, ethylene and hydrogen are added into a first reaction kettle, and a low-molecular-weight homopolymer is formed; adding ethylene, alpha-olefin and hydrogen into a second reaction kettle to form a high molecular weight copolymer; adding ethylene, hydrogen and alpha-olefin into a third reaction kettle to form a medium molecular weight copolymer; and performing post-treatment on the medium-molecular-weight copolymer to obtain the special material for the large hollow container. The structural composition of the product is optimized by designing the molecular weight and proportion of each kettle product in a three-kettle series connection process, so that the processability and mechanical property of the product are improved, and compared with the prior art, the processability and environmental stress cracking resistance of the resin are remarkably improved.

The present invention provides a shrinkage-resistant macroporous ultralight soft elastic supercritical foaming sole material and a preparation method thereof; the foaming sole material improves the flexibility / resilience / compressibility / mechanical strength of the foaming sole by using poly (1,2-butadiene)-b-polyethylene oxide copolymer, improves the cell strength by the double cross-linking effect of ethylene-methacrylic polymer, and effectively disperses ultra-high molecular weight polyethylene micropowder in the matrix and enhances the strength of large-aperture cells with carboxyl polystyrene microspheres, and then selects medium molecular weight polyisobutylene and cross-linking agent micro-cross-linking to further enhance the viscosity and strength of the matrix and effectively lock the gas, not only meeting the physical property requirements of consumers for lightness, softness and elasticity, thereby effectively preventing the shrinkage of the sole under the appearance of large pores, and improving the yield of the product and the stability and safety of mass production. In terms of technology, the ultra-high pressure foaming method is adopted, and the foaming time can be shortened by more than 50% compared with the traditional supercritical autoclave pressure, greatly improving the production efficiency.

The present invention provides for the synthesis of intermediate molecular weight heparin.

The application provides a composite implant containing different molecular weight agarose and a preparation method and application thereof, and belongs to the technical field of biomedical materials. The composite implant comprises two or more than two combinations of high molecular weight medical grade agarose, medium-high molecular weight medical grade agarose, medium molecular weight medical grade agarose and low molecular weight medical grade agarose. The application combines medical grade agarose with different molecular weights, so that the composite material has good injectability, moderate gel strength and controllable degradation performance. The prepared composite implant containing different molecular weight agarose has good antioxidant and anti-wrinkle effects, and has a wide application prospect in the field of skin anti-aging.

A high-strength multimodal polyethylene composition useful for the manufacture of plastic articles therefrom; a process for making the above-mentioned composition; and a pipe article made from the above-mentioned composition, the composition comprising a mixture of: (a) at least one first polymeric resin comprising a high molecular weight copolymer resin having a molecular weight greater than 350,000 g / mol; (b) at least one second polymeric resin comprising a low molecular weight homopolymer resin having a molecular weight less than 30,000 g / mol; and (c) at least one third polymeric resin comprising a medium molecular weight copolymer resin having a molecular weight of from 50,000 g / mol to 150,000 g / mol; wherein the high-strength multimodal polyethylene composition has a minimum required strength greater than 11.3 MPa.

The invention relates to the field of hyaluronic acid products, and particularly discloses a skin non-chronic wound repair dressing, sodium hyaluronates with two molecular weights are selected and matched to obtain composite sodium hyaluronate, and the sodium hyaluronate with the large molecular weight forms a protective layer on a skin wound to provide a relatively closed environment for the skin wound, so that the skin non-chronic wound repair dressing has a good application prospect. The risk that the wound surface is infected by external microorganisms is blocked, sodium hyaluronate with medium molecular weight is dissociated on the surface of the protective layer, a wet environment is provided for the skin wound surface by absorbing moisture of the environment and the skin, the skin cell activity is improved, and the wound surface skin repairing and healing speed is increased.

The invention discloses application of medium-molecular-weight gamma-polyglutamic acid in reduction of heavy metal accumulation of crops and promotion of crop growth, the relative weight-average molecular weight range of the medium-molecular-weight gamma-polyglutamic acid is 200-300 kDa, and meanwhile, the invention provides a preparation method of the medium-molecular-weight gamma-polyglutamic acid. By adding the medium-molecular-weight gamma-polyglutamic acid into the soil, heavy metals Cr and Cu in the soil absorbed by the cucumbers can be remarkably reduced, the content of proline is remarkably increased, the total oxidation resistance is improved, the content of malondialdehyde is remarkably reduced, and the growth of the cucumbers is promoted. According to the method disclosed by the invention, the polyglutamic acid is degraded by adopting a one-step method (gamma-PGA) to obtain the medium-molecular-weight polyglutamic acid (gamma-PGA), so that absorption and enrichment of cucumbers on heavy metals Cr and Cu in soil can be reduced, the growth and development of the cucumbers can be remarkably promoted, and the fresh weight of fruits can be increased.

The invention provides a mastic adhesive for 3LPP pipeline patching and anti-corrosion, a heat shrinkable tape and a preparation method thereof, wherein the mastic adhesive comprises the following components and their mass percentages: 15-25% maleic anhydride grafted hydrogenated thermoplastic elastomer, 3-7% high melt index ethylene methyl methacrylate, 15-20% low melt index ethylene methyl methacrylate, 3-7% cage polysilsesquioxane, 8-15% medium molecular weight polyisobutylene, 3-5% low molecular weight polyisobutylene, 15-25% tackifying resin, 10-20% nano active filler, 0.5-1% antioxidant, 0.5-1% anti-aging agent, and 1.0-1.5% masterbatch. The technical scheme of the invention is adopted to improve the maximum use temperature of mastic-based hot melt adhesive, greatly improve the wettability of mastic hot melt adhesive to adherends, improve the bonding strength and high temperature resistance of adhesive, have better thermal stability, mechanical properties and flame retardancy, and have lower cost.

The invention belongs to the technical field of textile printing and dyeing, and discloses a color fixing agent for polyester and a preparation method thereof. Polyethyleneimine, glycidyl methacrylate, a cationic monomer and 1-allylimidazole are used as main raw materials, a novel cationic polymer is constructed through amido epoxy ring opening and free radical copolymerization, the cationic polymer has a medium molecular weight, and a molecular chain is rich in acting force anchor points, so that the cationic polymer can be used for preparing a polymer with high molecular weight. Strong electrostatic adsorption, hydrogen bonds, Van der Waals force and the like can be generated with polyester groups, carboxyl groups and dye molecules on the fibers at the same time, so that the affinity adsorption of the dye to the fibers is ensured. Moreover, the color fixing agent molecules with medium chain length can realize rapid permeation in the fiber, and can wrap the dye molecules sufficiently, so that the color fixing effect is improved.

The invention relates to a preparation method and application of food-grade medium-molecular-weight tremella polysaccharide, and belongs to the technical field of fungal polysaccharide preparation. The preparation method of the food-grade medium-molecular-weight tremella polysaccharide comprises the steps of pretreatment, tremella base fermentation, primary enzymolysis, solvent extraction, secondary enzymolysis, separation, purification and the like. The tremella polysaccharide extracted by the method disclosed by the invention is relatively high in extraction rate, relatively high in pharmacological activity and remarkable in antioxidant activity.

The present invention belongs to the technical field of polyether preparation, and discloses a preparation method of a high molecular weight silane-modified polyether. The preparation method includes the following steps: preparing a low molecular weight polyether polyol; preparing a medium molecular weight polyether polyol; preparing a high molecular weight polyether polyol; and subjecting the high molecular weight polyether polyol and a silane coupling agent to a capping reaction to obtain a high molecular weight silane-modified polyether. The preparation method provided by the present invention uses a polyol as an initiator, and prepares a high molecular weight polyether polyol through a three-step method with propylene oxide, and then uses a silane coupling agent for capping to obtain a high molecular weight silane-modified polyether. The present invention prepares polyether through a three-step method, strictly controls the molecular weight and reaction temperature of the polyether polyol in each step, and adds a small molecule alcohol and an antioxidant after the reaction, so that the prepared high molecular weight silane-modified polyether has a small viscosity, strong storage stability, and small changes in viscosity and color during storage.

An underwater viscoelastic anti-corrosion adhesive a preparation method thereof, and an underwater viscoelastic anti-corrosion tape are provided, which belong to the technical field of underwater anti-corrosion. Total weight component of the underwater viscoelastic anti-corrosion adhesive includes: 20 to 35 parts of medium molecular weight polyisobutylene, 8 to 15 parts of hydrocarbon compounds, 20 to 35 parts of bentonite, 10 to 20 parts of silicate, 10 to 20 parts of inorganic filler and 0 to 2 parts of anti-aging agent.

The invention provides a phenolic moulding compound for a lithium battery separator. The phenolic moulding compound comprises the following raw materials: medium molecular weight thermoplastic phenolic resin, high molecular weight thermoplastic phenolic resin, bakelite plate powder, wollastonite fiber, a urotropine curing agent, a curing accelerator and a release agent. According to the phenolic moulding plastic provided by the invention, the bakelite plate powder is used as a filler instead of wood powder, and a certain amount of high-molecular-weight thermoplastic phenolic resin is added on the basis of adding the medium-molecular-weight thermoplastic phenolic resin under the condition that the preparation processability of the phenolic moulding plastic is not influenced, so that the phenolic moulding plastic has better heat resistance and rigidity; the raw materials are easy to obtain, the preparation process is simple, the cost is relatively low, and the high-temperature dimensional stability of the general phenolic moulding plastic can be greatly improved.

The application discloses a kind of metallocene catalyst system, polyisobutylene and preparation method thereof.The metallocene catalyst system includes A, B, C, D four components;Component A is metallocene complex;Component B is borate;Component C is alkyl aluminum;Component D is selected from alkyl ether of carbon atom number 2~8.The metallocene catalyst system used in the application has high catalytic activity and raw materials are cheap and easy to obtain, which can greatly reduce production cost.Compared with BF3 catalyst system, the catalyst system provided by the application is non-toxic, harmless, non-polluting, non-corrosive, which can effectively solve the technical problems of toxic, harmful, corrosion and pollution existing in traditional technical route, thereby improving the operating environment, and ensuring personal health.The application can synthesize narrow distribution, medium molecular weight polyisobutylene under mild conditions of 0~80 DEG C, i.e., using conventional cooling water to remove heat, which solves the low temperature reaction problem existing in traditional cationic polymerization.

The present invention belongs to the field of polyether polyol synthesis, and specifically relates to low-viscosity, high-molecular-weight polyether polyol and its preparation method. It is prepared by the following steps: using a small-molecule diol as an initiator, under the action of an alkali metal catalyst, using propylene oxide as a polymerization monomer, heating reaction, neutralization, dehydration, and filtration to obtain a low-molecular-weight polyether polyol; using a low-molecular-weight polyether polyol as an initiator, under the action of a double metal cyanide catalyst, using propylene oxide as a polymerization monomer, and preparing a medium-molecular-weight polyether polyol through induction and polymerization. Using a medium-molecular-weight polyether polyol as an initiator, under the action of a double metal cyanide catalyst, using propylene oxide as a polymerization monomer, and preparing a high-molecular-weight polyether polyol through pre-induction, induction, and polymerization; the high-molecular-weight polyether polymerization stage of the present invention adds a pre-induction process, which effectively improves the activation rate of the catalyst, and the prepared polyether polyol has a low unsaturation value and low viscosity.

The invention belongs to the field of polymer chemical recovery, and discloses a method for preparing high-molecular-weight and mechanical-property PCL (polycaprolactone) through efficient polycondensation of low / medium-molecular-weight PCL. The method comprises the following steps: heating dried low / medium molecular weight PCL and a catalyst to 140-270 DEG C under the pressure condition of 10-500KPa, carrying out polycondensation reaction for 3-24 hours, and separating water generated by the polycondensation reaction from a reaction system in the reaction process to obtain high molecular weight PCL. The method is simple, efficient chemical recycling of low / medium molecular weight PCL is achieved, and high molecular weight and mechanical property PCL is formed through polycondensation. The molecular weight of the product is as high as 5.08 * 10 < 4 > g / mol, and the tensile strength and the elongation at break of the product respectively reach 31.1 MPa and 1420%, which are superior to those of commercial PCL.

The present invention comprises (i) an amorphous polymer composition containing one or more polyisobutenes, each having a glass transition temperature of -40°C or lower, as determined by differential scanning calorimetry (DSC); (ii) one or more butyl rubbers; (iii) one or more antioxidants; and (iv) one or more filler materials, wherein the one or more polyisobutenes have an average molecular weight in the range of about 500 to about 20,000 M v Low molecular weight polyisobutene (LMW PIB) having a molecular weight in the range of approximately 20,000 to approximately 120,000 M v The present invention relates to a corrosion-preventive composition for protecting articles from corrosion, independently selected from the group consisting of medium molecular weight polyisobutenes (MMW PIBs) having the following properties.

The present invention discloses Aureobasidium pullulans and its application and a method for producing medium-molecular-weight pullulan polysaccharide, belonging to the technical field of microorganisms. The Aureobasidium pullulans of the present invention is Aureobasidium pullulans ( Aureobasidium pullulans ) SYCY-018, which was deposited in the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on December 26, 2022, with the deposit number of CGMCC NO. 40467. In the present invention, the Aureobasidium pullulans SYCY-018 is inoculated into a fermentation medium for fermentation to produce pullulan polysaccharide. The yield of medium-molecular-weight pullulan polysaccharide is as high as over 150 g / L, and it also has good genetic stability and high temperature resistance. Even at a high temperature of 40 °C, the yield of pullulan polysaccharide can still be higher than 130 g / L, which is suitable for industrial production.

The present invention relates to a composition for protecting an article from corrosion, in which the corrosion protection composition comprises: (i) an amorphous polymer composition comprising one or more polyisobutylene, each of which has a glass transition temperature of-40 DEG C or less as determined by differential scanning calorimetry (DSC); (ii) one or more butyl rubbers; (iii) one or more antioxidants; and (iv) one or more filler materials wherein the one or more polyisobutylene is independently selected from the group consisting of low molecular weight polyisobutylene (LMW PIB) having an average molecular weight Mv in the range of about 500 to about 20,000, and medium molecular weight polyisobutylene (MMW PIB) having an average molecular weight Mv in the range of about 20,000 to about 120,000.

The present application relates to the field of paint technology, and disclose a kind of high filling super-solidification intermediate coating in rail transit field, and intermediate coating composition includes nanometer titanium dioxide base end hydroxyl hyperbranched polyester, medium molecular weight acrylic resin, blocked high functionality polyisocyanate crosslinking agent, dispersant etc..The super-solidification system of nanometer titanium dioxide base end hydroxyl hyperbranched polyester and isocyanate crosslinking agent used in the present application obtains coating crosslinking density, and toughness is good, significantly improves the resistance of coating resistance, such as water resistance, moisture resistance, achieves higher level of protection effect to putty, especially water resistance can reach 48h, meanwhile, the intermediate coating of the present application is quick-drying, easy to construction, has higher gloss and fullness, leveling property, matched high-performance putty and finish, can be widely used in rail transit field, and realizes life cycle performance guarantee.

This invention discloses a method for preparing medium molecular weight bisphenol A propane glycidyl ether. The method involves etherifying bisphenol A propane with epichlorohydrin using a polyethylene glycol-modified ionic liquid as a phase transfer catalyst. The resulting etherification product then undergoes a ring-closure reaction under an alkaline catalyst to obtain the medium molecular weight bisphenol A propane glycidyl ether. Compared to the traditional one-step production process, this method offers advantages such as high yield, good selectivity, low wastewater generation, and concentrated molecular weight distribution, thus meeting the application needs of the coatings industry.