57 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 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 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 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 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 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 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.

A method of synthesis of medium molecular weight heparin includes the steps of dissolving unfractionated heparin in an aqueous solvent to provide a first solution; adding an oxidising agent to the first solution to provide a second solution; and incubating the second solution at a temperature of from about 15 °C to about 30 °C to form a medium molecular weight heparin solution.

The invention provides synthesis of medium molecular weight heparin.

The present invention relates to an implantable paste comprising bioactive glass powder having a size distribution of 0.5-45 μm, bioactive glass granules having a size distribution between 100 and 4000 μm, low molecular weight polyethylene glycol having a molecular weight range of 200-700 g / mol, medium molecular weight polyethylene glycol having a molecular weight range of 700-2500 g / mol, high molecular weight polyethylene glycol having a molecular weight range of 2500-8000 g / mol and glycerol. The composition of the bioactive glass is 45-55 weight-% of SiO2, 20-25 weight-% of Na2O, 18-25 weight-% of CaO and 3-6 weight-% of P2O5, and the molecular weight of the low molecular weight polyethylene glycol and of the medium molecular weight polyethylene glycol differ from each other by at least 80 g / mol and that the molecular weight of the medium molecular weight polyethylene glycol and of the high molecular weight polyethylene glycol differ from each other by at least 300 g / mol.

The invention provides a hair repair recombinant collagen peptide composition as well as a preparation method and application thereof, and relates to the technical field of hair care. The hair repair recombinant collagen peptide composition comprises low-molecular-weight recombinant collagen peptide with the molecular weight smaller than 1 kDa, medium-molecular-weight recombinant collagen peptide with the molecular weight ranging from 1 kDa to 5 kDa and high-molecular-weight recombinant collagen peptide with the molecular weight larger than 5 kDa, and the proportion of the high-molecular-weight recombinant collagen peptide is smaller than 8%. The sum of the proportions of the medium-molecular-weight recombinant collagen peptide and the low-molecular-weight recombinant collagen peptide is greater than 92%. By reasonably controlling the proportion of recombinant collagen peptides with different molecular weights, sufficient small-molecular-weight components can effectively permeate into hair, sufficient medium-molecular-weight components are provided to increase repair functional sites, a small amount of large-molecular-weight components are reserved to enhance the repair effect, and the effects of repairing and smoothing hair cuticles are achieved; and the optimal repairing effect is achieved.

Provided in the present invention are a new bio-based ternary polymer, and a preparation method therefor and the use thereof. The new bio-based ternary polymer comprises itaconic acid, monoethyl itaconate and diethyl itaconate units. The medium-molecular-weight bio-based ternary polymer with good performance is synthesized from the monomers under optimized synthesis conditions in the presence of substances such as a molecular weight regulator, and is applied to dishwashing liquids, dishwasher tablets, laundry detergent powders, laundry detergent liquids, etc. The ternary polymer provided by the present invention has significant effects in terms of hard water tolerance and the inhibition of various calcium scales; and after a dishwasher detergent powder prepared from the ternary polymer of the present invention is used for washing a glass, it is observed that the glass is transparent, bright, scale-free, water-stain-free, spot-free and film-free.

The scheme provides a cleavage method of low molecular weight aldehyde carboxyl rubber, which comprises the following steps: dissolving rubber in an organic solvent to obtain a rubber solution; heating the rubber solution, adding sodium metavanadate solution and mixing uniformly to obtain a mixed solution; adding hydrogen peroxide drop by drop into the mixed solution until the cleavage reaction is completed to obtain a reaction solution, wherein the molar ratio of the total amount of hydrogen peroxide to the carbon-carbon double bond in the rubber is (1.2-2.5):1; and treating the reaction solution to obtain low molecular weight aldehyde carboxyl rubber. The method can reduce the cost, improve the environmental protection, significantly improve the functional group content and reaction efficiency of the product, and provide a better choice for the large-scale production and application of low molecular weight aldehyde carboxyl rubber.

The present invention discloses an antibacterial lotion for treating tinea pedis and a preparation method thereof. The lotion is made from natural phenols with small molecular weight, medium molecular weight, large molecular weight and a water-soluble polymer adjuvant. Preferably, they are eugenol, pine bark extract, tannic acid and poloxamer. The mass of each component is 2-10 parts of eugenol, 5-10 parts of pine bark extract, 5-10 parts of tannic acid, 1-5 parts of poloxamer, and 1-5 parts of water. Tannic acid in the present invention has astringency and bactericidal properties, eugenol has bactericidal properties, and pine bark extract has antibacterial properties. When the three are used in combination, they can effectively treat tinea pedis and reduce the peeling phenomenon after application.

This invention discloses a composite cationic flocculant based on a dual gradient of molecular weight and charge density, along with its preparation and application methods. The flocculant is composed of a medium-molecular-weight, high-charge-density poly(diallylammonium chloride)-acrylamide copolymer (PDA) and a high-molecular-weight, medium-low-charge-density cationic polyacrylamide (CPAM), with an effective mass ratio of 10:1 to 20:1. The mass charge density of PDA is 2 to 3 times that of CPAM. A gradient shear mixing preparation process and a time-sequential synergistic flocculation application method based on differences in diffusion kinetics are employed. Through a relay effect of rapid charge neutralization (0-30 seconds) and slow bridging (30-180 seconds), the flocculant can form a skeleton-filled floc structure, achieving adaptive interception of dissolved organic matter and complexation-encapsulation and fixation of heavy metals. This invention can significantly shorten plate and frame filter press time and reduce the moisture content of the filter cake and the concentration of pollutants in the effluent.

A functionalised medium molecular weight heparin includes a linker and a functional group. The functional group may be a polar functional group, an apolar functional group, an acidic functional group, or a basic functional group. The functional group may be an aryl, a phenyl, a heteroaryl, an alkyl, a cycloalkyl, an alkenyl, an alkynyl, an alcohol, a thiol, an ether, a sulphide, an amine, a carboxylic acid, and / or a fluoroalkyl. The linker may be an oxime linker or an amine linker.

The invention provides a cracking method of medium-low molecular weight aldehyde-terminated carboxyl rubber. The cracking method comprises the following steps: dissolving rubber by adopting an organic solvent to obtain a rubber solution; heating the glue solution, adding a sodium metavanadate solution, and uniformly mixing to obtain a mixed solution; dropwise adding hydrogen peroxide into the mixed solution until the cracking reaction is finished to obtain a reaction solution, wherein the molar ratio of the total usage amount of the hydrogen peroxide to the carbon-carbon double bond in the rubber is (1.2-2.5): 1; the method has the advantages that the cost is reduced, the environmental protection property is improved, the functional group content and the reaction efficiency of the product are obviously improved, and a better choice is provided for the large-scale production and application of the medium-low molecular weight aldehyde-terminated carboxyl rubber.

The present invention provides a wool keratin and its application. By carrying out refined preparation on the prepared wool keratin, keratins with different effects and different molecular weights can be obtained. The three kinds of keratins prepared by the present invention have different molecular weights. The wool keratin amino acids can easily penetrate into the hair cortex and crosslink with the hydrophilic groups exposed in damaged hair quality to form bonds, playing the roles of moisturizing, strengthening and repairing hair, and are suitable for forked and dry hair. The medium molecular weight wool keratin is rich in proteins and polypeptide fragments, can combine with hair to form a water-insoluble polymer, and form a transparent film with a certain elasticity and strength on the hair surface, thereby improving hair elasticity, consolidating the care effect, enhancing hair luster, and playing the roles of repairing and lubricating hair filaments. The low molecular weight wool keratin contains various free amino acids and protein polypeptide fragments at the same time, acts on hair to endow hair with a moist and smooth touch, and is suitable for hair of ordinary hair quality.