112 results about "Dimethyl ester" patented technology

The invention relates to a low-cost composite metal catalyst which is a CuO / ZnO / Al2O3 composite metal catalyst, and the molar ratio of CuO to ZnO to Al2O3 is (6-4): (3-4): (0.5-1). The composite catalyst is prepared by the following steps: adding carbonate into a mixed salt aqueous solution of copper salt, zinc salt and aluminum salt for co-precipitation, grinding a filter cake, and roasting at high temperature. According to the catalyst, 1, 12-dodecanedioic acid dimethyl ester which is low in price and easy to obtain can serve as a raw material, 1, 12-dodecanediol is prepared through catalytic hydrogenation under the milder condition compared with the prior art, high yield and low cost are achieved on the premise that the process condition control difficulty is greatly reduced and the process safety is improved, and the problems that in the prior art, 1, 12-dodecanedioic acid dimethyl ester is synthesized, and the cost is low are solved. The technical problems of high energy consumption, expensive catalyst, harsh reaction conditions and difficult realization of industrial production in the reaction process of 1, 12-dodecanediol in the prior art are solved.

The invention discloses an application of a silica-sulfonic acid type solid acid catalyst in the preparation of dimethyl 2,5-furandicarboxylate. The dimethyl 2,5-furandicarboxylate is obtained by catalyzing the esterification reaction of 2,5-furandicarboxylic acid and methanol with a silica-sulfonic acid type solid acid catalyst; wherein the silica-sulfonic acid type solid acid catalyst is obtained by grafting, oxidizing and sulfonating silica and a silane coupling agent. The silica-sulfonic acid type solid acid catalyst in the present invention is easy to recover, and has good thermal stability and reusability; the preparation process of dimethyl 2,5-furandicarboxylate provided at the same time has little corrosion to equipment, simple wastewater treatment, mild reaction and high economy.

The invention provides a novel hindered amine light stabilizer as well as a preparation method and application thereof, and relates to the field of light stabilizers. According to the preparation method of the novel hindered amine light stabilizer, specific dibasic acid dimethyl ester and 2, 2, 6, 6-tetramethylpiperidinol are used as raw materials, an alkane solvent or a benzene solvent is used as a solvent, and a catalytic reaction solution is obtained through a heating reaction under the condition of a catalyst; and neutralizing and washing the catalytic reaction liquid to obtain the novel hindered amine light stabilizer. According to the preparation method, ideal preparation effects (such as purity, yield and the like) can be achieved, meanwhile, the chroma of the product is effectively reduced, the problem that the product is prone to yellowing due to the fact that the hindered amine light stabilizer absorbs visible light is solved, and the compatibility and stability of the hindered amine light stabilizer and a high polymer material are further improved.

The invention provides a method for preparing 1, 4-cyclohexanedimethanol by efficiently degrading PET (polyethylene terephthalate) waste plastics through a three-step method. In the method, the first step is that PET waste plastics are subjected to alcoholysis degradation to obtain dimethyl terephthalate, the second step is that the supported Ru-based catalyst catalyzes dimethyl terephthalate hydrogenation to prepare 1, 4-cyclohexanedicarboxylic acid dimethyl ester, and the third step is that the Cu-based catalyst catalyzes the 1, 4-cyclohexanedicarboxylic acid dimethyl ester to prepare the 1, 4-cyclohexanedimethanol. The catalyst is simple and convenient to prepare, low in cost and easy to recover, the product is easy to separate, the reaction process is green and environment-friendly, and conditions are mild. According to the technical scheme, the novel method for preparing the important polyester monomer 1, 4-cyclohexanedimethanol through efficient catalysis of the PET waste plastics is provided, waste is turned into wealth, and the method has excellent application prospects.

The invention relates to the technical field of cables, and provides a corrosion-resistant control cable and a preparation method thereof. The corrosion-resistant control cable sequentially comprises a conductor, an insulating layer, a shielding layer and a sheath layer from inside to outside, wherein the sheath layer comprises the following components in parts by weight: 50-70 parts of polyvinyl chloride, 15-25 parts of ethylene propylene diene monomer, 10-20 parts of modified graphene oxide, 0.5-1.5 parts of an antioxidant, 3-5 parts of a plasticizer, 15-20 parts of a flame retardant, 2-4 parts of a compatilizer, 4-5 parts of an active agent, 1-3 parts of an assistant crosslinking agent and 1-3 parts of a crosslinking agent; wherein the modified graphene oxide is obtained by modifying graphene oxide with dimethyl 5-hydroxyisophthalate and N-hydroxymethyl acrylamide. According to the technical scheme, the problem of insufficient corrosion resistance of the control cable in the prior art is solved.

The invention provides a preparation process for producing mixed dibasic acid dimethyl ester by using ionic liquid as a catalyst, which belongs to the technical field of fine chemical engineering, and comprises the following steps: S1, dissolving carbazole in anhydrous acetonitrile, adding bromoethane, reacting, then carrying out rotary evaporation, washing and precipitating, dissolving the precipitate in ethanol, then adding a LiHSO4 solution for ion exchange, centrifuging, and then carrying out vacuum drying to obtain mixed dibasic acid dimethyl ester; the carbazolyl ionic liquid catalyst is obtained; and S2, adding the carbazolyl ionic liquid catalyst, mixed binary acid and methanol into a pre-reactor, reacting to obtain a pre-reaction solution, feeding the pre-reaction solution into an extraction tower, adding an ionic liquid-methanol mixed solution, carrying out countercurrent reaction-extraction to obtain a light-phase product from the top of the extraction tower, carrying out silica gel adsorption, feeding the light-phase product into a rectifying tower, and removing methanol to obtain the carbazolyl ionic liquid. And stirring, adsorbing and filtering to obtain the mixed dibasic acid dimethyl ester. According to the invention, the purposes of high product purity, production process optimization and cost reduction can be achieved.

The invention discloses transparent copolyester, a preparation method thereof and a product prepared from the copolyester. The preparation method comprises the following steps: carrying out esterification or ester exchange reaction on dibasic acid or dimethyl ester of the dibasic acid and dihydric alcohol at 5-300kPaG to obtain an esterified substance or an ester exchange substance; then, the normal pressure of the system is recovered, the esterification or ester exchange temperature is kept unchanged, the negative pressure of the ester or ester exchange material is gradually reduced to high vacuum according to a certain pressure reduction rate, excessive monomers are removed, the content of impurities generated by the ester or ester exchange material is 0.3 wt% or below, and a prepolymer is obtained; and further heating the prepolymer, and carrying out final polycondensation reaction under high vacuum to obtain the target copolyester. The method can effectively weaken the side reaction in the synthesis process, improve the hue of the copolyester product, improve the light transmittance, reduce the haze and improve the heat resistance. Products prepared from the copolyester, such as bottle materials, sheets, plates and membrane materials, have the characteristics of light color, high transparency and good heat resistance.

The invention discloses application of dikafen phenolic acid and ester derivatives thereof in preparation of medicines for treating pulmonary fibrosis. On an MRC-5 cell model induced by TGF-beta1, the bikafen phenolic acid and the multiple ester derivatives thereof show the activity of inhibiting alpha-SMA and COL1A1 protein expression; on a bleomycin-induced pulmonary fibrosis mouse model, the dimethyl ester derivative of the dikafen phenolic acid shows a good protective effect on experimental animals. Therefore, the dicafen phenolic acid and the ester derivative thereof have good application in the field of preparation of medicines for treating pulmonary fibrosis diseases.

The application discloses a kind of molecular sieve supported silver monatomic catalyst and its preparation method and application.The catalyst is with molecular sieve as carrier, by silver precursor salt aqueous solution is impregnated to molecular sieve, after drying and with carbon powder mixing, again be placed in joule heat in-situ heating device, at 600 DEG C~1200 DEG C high temperature pyrolysis 5~8 seconds preparation;Wherein silver element mass content is 0.2 wt%~3 wt%.The catalyst prepared by the application realizes that silver monatomic atom is highly dispersed on molecular sieve, and metal utilization rate reaches 100%.The catalyst is applied to oxalic acid dimethyl ester electrocatalytic reduction coupling preparation tartaric acid dimethyl ester reaction, and excellent catalytic performance is shown: at optimum potential, target product tartaric acid dimethyl ester selectivity is as high as 95.3%, faraday efficiency reaches 82.9%, conversion frequency reaches 1880 h ‑1 , and has excellent long-term electrochemical stability.

The present invention relates to a method of adding an isocitrate lyase specific inhibitor to a lactic acid fermentation process to block the production of succinic acid as a byproduct of fermentation. The specific inhibitor includes a combination of one or more of glycolic acid methyl ester, malonic acid dimethyl ester, hydroxymalonic acid diethyl ester, 3-nitropropionic acid ethyl ester, mercuric chloride, or 5,5'-dithiobis(2-nitrobenzoic acid) to effectively reduce the amount of succinic acid in the lactic acid.

The invention discloses a bio-based nylon composite material and a preparation method thereof, and relates to the technical field of polymer materials. When preparing the bio-based nylon composite material, the present invention first modifies shell powder with a silane coupling agent to obtain silicon-hydrogen modified shell powder; reacts N-hydroxyethyl maleimide with allyl phosphine dichloride to obtain bismaleimide monomer; reacts bismaleimide monomer with silicon-hydrogen modified shell powder to obtain modified shell powder; reacts dibutyl oxalate with methylguanamine to obtain multi-hydrogen bond monomer; reacts furfurylamine with methyl acrylate to obtain side furanyl dimethyl ester; solid-phase polymerization of side furanyl dimethyl ester, 1,10-decanediamine, and multi-hydrogen bond monomers to obtain modified bio-based nylon; and melt-extrudes and granulates the modified bio-based nylon and the modified shell powder to obtain a bio-based nylon composite material. The bio-based nylon composite material prepared by the present invention has the advantages of high mechanical strength, flame retardancy, self-repairing, and good heat resistance.

The invention relates to an ultrahigh-temperature and high-salinity water shutoff system and a preparation method and application thereof, and belongs to the field of oilfield water shutoff systems, and the ultrahigh-temperature and high-salinity water shutoff system comprises the following substances in parts by weight: 8-10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 6-10 parts of N-vinyl caprolactam, 6-8 parts of N-isopropylacrylamide and 4-6 parts of monostearyl maleate. The invention relates to a water-based adhesive which is prepared from the following components in parts by weight: 6 to 10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3 to 5 parts of dimethylaminoethyl methacrylate, 0.2 to 0.4 part of dimethyl 2-butenedioate trimethylolpropane triacrylate, 3 to 5 parts of modified nanoscale silicon dioxide, 2 to 4 parts of modified nanoscale calcium carbonate and 100 to 120 parts of deionized water. The plugging agent provided by the invention can still maintain good plugging performance in an oil reservoir environment in which the underground temperature of an oil field exceeds 120 DEG C and / or the degree of mineralization is higher than 100000mg / L, so that the plugging efficiency of a water seepage layer of an oil well in the oil field is ensured.

The utility model relates to the field of catalyst recycling technology, especially relates to a carbonic acid dimethyl ester synthesis is with catalyst recycling device. Including recovery jar, the recovery jar is installed with the stirring assembly for stirring catalyst, the recovery jar is installed with the heating assembly for heating catalyst, recovery assembly is installed on the recovery jar for recycling the hot air of discharge, the utility model discloses through the setting of recovery assembly, and the recovery jar exhausts the hot and humid gas and exchanges heat with the outside air in the heating box, and the preheating of air is carried out, thereby reducing the temperature difference of the air that advances the wind and heats to dry exhaust air, realizes the recycling of the waste heat in the hot and humid gas, reduces the energy waste that the direct discharge of heat causes, and reduces the energy consumption cost of heating process.

The invention belongs to the technical field of medicine detection, and particularly relates to dipropyl malonic acid prepared by a dimethyl malonate method and a detection method of impurities of the dipropyl malonic acid. According to the detection method provided by the invention, the dipropyl malonic acid prepared by a dimethyl malonate method and impurities thereof are detected through high performance liquid chromatography (HPLC) for the first time; the impurities comprise propyl malonic acid, 2-methyl-2-propyl malonic acid, 2-propyl-2-butyl malonic acid, propyl malonic acid monomethyl ester, 2-methyl-2-propyl malonic acid monomethyl ester, dipropyl malonic acid monomethyl ester, 2-propyl-2-butyl malonic acid monomethyl ester, propyl malonic acid dimethyl ester, dipropyl malonic acid monopropyl ester and propyl malonic acid dimethyl ester; the invention relates to a method for preparing dipropyl malonic acid, which is selected from one or more of dipropyl malonic acid dimethyl ester, dipropyl malonic acid methyl ester propyl ester and 2-propyl-2-butyl malonic acid dimethyl ester, and solves the problems of quality control and process evaluation of dipropyl malonic acid serving as an intermediate of sodium valproate prepared by a dimethyl malonate method.

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 invention discloses a gram-level synthesis method of Dactyllactone A. The gram-level synthesis method of Dactyllactone A is shown in the description. The method comprises the following steps: with simple and easily available aryl iodide, aziridine and triisopropyl silylacetylene as starting materials, stirring and reacting in an organic solvent at 60-70 DEG C under the action of a palladium catalyst, a phosphine ligand, a norbornene derivative and alkali to obtain a key intermediate; the key intermediate is condensed with iodo gem-dimethyl ester furanone prepared from propiolic acid and dimethyl malonate iodine ylide, and then the condensation product is subjected to an Au / Ag catalyzed intramolecular hydroamination reaction, photocatalytic 6-pi electro-cyclization and two-step conversion, so that the natural product Dactyllactone A can be obtained, wherein the iodo gem-dimethyl ester furanone and iodo gem-dimethyl ester furanone are prepared from propiolic acid and dimethyl malonate iodine ylide. The method has the advantages of cheap and easily available raw materials, short reaction steps, high reaction efficiency, large preparation scale, simple preparation process and the like, has great application potential, and lays a good foundation for industrial production.

The utility model relates to carbonic acid dimethyl ester production technical field, and disclose a kind of carbonic acid dimethyl ester production device of continuous feeding, the bottom surface of feed hopper is fixedly installed with conveying pipe, the inside of conveying pipe is fixedly installed with gear, the outside of gear is engaged to be connected with transmission crawler belt, the side surface of transmission crawler belt is fixedly installed with hopper, the bottom surface of conveying pipe is fixedly installed with discharge hopper, the bottom surface of discharge hopper is fixedly installed with recombinant component separation device.This carbonic acid dimethyl ester production device of continuous feeding, raw material is entered into conveying pipe by feed hopper, in conveying pipe, raw material will fall into hopper, hopper is driven by gear to transport raw material by transmission crawler belt, compared with ordinary transmission device, transmission crawler belt can adapt to bending lifting operation, and it has longer service life, and individual component can be replaced and repaired, maintenance cost is also lower in later period, hopper not only can transport solid raw material, but also can transport liquid raw material.

The invention discloses a synthesis method of N-goose deoxycholyl-L-aspartic acid and application of the N-goose deoxycholyl-L-aspartic acid in preparation of a medicine for improving metabolism-related fatty liver diseases. According to the method provided by the invention, chenodeoxycholic acid and L-dimethyl aspartate hydrochloride are taken as raw materials, and a chenodeoxycholic acid-dimethyl aspartate intermediate is synthesized, so that a target compound-N-chenodeoxycholyl-L-aspartic acid with a brand new structure is efficiently prepared. The compound shows a treatment effect superior to that of obeticholic acid (OCA) in an animal model, and can effectively improve multiple indexes such as fatty degeneration, inflammation and fibrosis of the liver. The invention provides a brand new solution for major clinical challenges of insufficient curative effect, large side effect, drug withdrawal rebound and the like of the current MAFLD treatment drug, and provides a candidate compound with a wide prospect for developing a novel efficient MAFLD treatment drug.

The invention discloses a method for quantitatively analyzing the content of dimethyl furandicarboxylate (DMFDCA) through a nuclear magnetic resonance hydrogen spectrum technology, which adopts an internal standard substance ethylparaben which meets the national standard and does not react with a standard substance to directly measure the content of the main component DMFDCA in the standard substance. The method comprises the following steps: dissolving ethylparaben and DMFDCA in deuterated dimethyl sulfoxide DMSO-d6 to obtain a solution to be detected, optimizing test parameters, determining a nuclear magnetic resonance hydrogen spectrum of the solution to be detected, selecting proper quantitative peaks of ethylparaben and DMFDCA, respectively integrating the quantitative peaks of ethylparaben and DMFDCA to obtain integral areas, and calculating the actual content of DMFDCA according to a formula. The method has the characteristics of simplicity, feasibility, low cost, good stability, high precision, strong specificity and the like, and has wide application prospects in the aspects of standard substance calibration, intermediate check and the like.

The application provides a 2-amino terephthalic acid dimethyl ester-tetracyano benzene eutectic crystal as well as a preparation method and application thereof, the eutectic crystal is of a triclinic system, a space group is a cell parameter is alpha = 95.041 (2) °, beta = 90.337 (2) °, gamma = 97.670 (2) °, and a cell volume is The 2-amino terephthalic acid dimethyl ester-tetracyano benzene eutectic crystal provided by the application increases the solid melting point of the organic compound from 133.39 DEG C to 162.23 DEG C without changing the covalent bond of the compound, enhances the thermal stability, and meanwhile, the fluorescence emission color, the fluorescence lifetime and the quantum yield are obviously changed.

The invention discloses a polyurethane resin modified acetic acid-propionic acid emulsion as well as a preparation method and application thereof, and belongs to the technical field of emulsions for glass fibers. The emulsion is prepared from the following raw materials in parts by weight: 200 to 300 parts of butyl acrylate, l70 to 210 parts of vinyl acetate, 10 to 15 parts of methacrylic acid, 8 to 15 parts of dimethyl ester, 5 to 10 parts of polyurethane resin, 5.0 to 6.0 parts of nonionic emulsifier, 4.0 to 5.0 parts of anionic emulsifier, 0.5 to 1.5 parts of initiator, 0.4 to 0.9 part of sodium bicarbonate and 350 to 400 parts of water. The preparation method comprises the following steps: (1) weighing the raw materials; (2) heating, stirring and dispersing the nonionic emulsifier, the anionic emulsifier and part of water to obtain a pre-emulsion; and (3) firstly stirring butyl acrylate, vinyl acetate, methacrylic acid, dimethyl ester and polyurethane resin, then adding the rest water and sodium bicarbonate, continuously stirring, heating, adding an initiator for reaction, finally dropwise adding the pre-emulsion, keeping the temperature and cooling to obtain the water-based adhesive. And polyurethane is used for modification, so that the water resistance and the heat resistance of the modified glass fiber are improved, and the modified glass fiber has excellent performance when being used on the glass fiber.

The application provides a copper-based ester hydrogenation catalyst and a preparation method and application thereof, and a preparation method of 1,4-cyclohexanedimethanol, and belongs to the field of catalytic chemistry. The method comprises the following steps: mixing a soluble copper salt, a metal additive soluble salt, an alkaline substance and water to carry out a precipitation reaction to obtain a hydroxide precipitate; mixing the hydroxide precipitate with a pore expanding agent and then maintaining to obtain a mixture; and sequentially carrying out water washing, drying and calcination on the mixture to obtain the copper-based ester hydrogenation catalyst. The copper-based ester hydrogenation catalyst with high pore diameter and high specific surface area is prepared by mixing the pore expanding agent with the alkaline substance to expand the pores, and the catalyst is particularly suitable for preparing CHDM by hydrogenating 1,4-cyclohexanedimethyl acid dimethyl ester, and CHDM with a trans ratio of more than 75% can be obtained at a lower temperature.

The invention discloses a preparation method and application of metal organic framework immobilized ligase. The immobilized enzyme is prepared by encapsulating a high-performance ligase mutant Q186G / S328A with an amino acid sequence as shown in SEQ ID NO: 2 into a ZIF-8 framework in situ. The immobilized enzyme has high catalytic activity and high alpha-regioselectivity of the mutant and excellent stability brought by ZIF-8 encapsulation. When being used for catalyzing condensation of L-aspartic acid-alpha, beta-dimethyl ester and L-phenylalanine to prepare an aspartame key intermediate alpha-AMP, the alpha-AMP has the conversion rate, selectivity and operation stability which are superior to those of free enzyme, and can be recycled for multiple times while the activity is kept good. The invention provides a brand-new enzyme catalysis process for green, efficient, economical and industrial synthesis of aspartame.

The present application relates to the field of furan-based polyester composite materials, and particularly relates to a high-mechanical-property, high-barrier, degradable polydopamine nanosheet / furan-based polyester composite material and a preparation method thereof. By blending polydopamine nanosheets, the degradable furan-based polyester has the advantages of hydrogen bonding and nanocomposite modification, and is endowed with diversified comprehensive performance. The polydopamine nanosheet, dimethyl 2,5-furandicarboxylate, aliphatic dicarboxylic acid dimethyl ester, aliphatic diol and catalyst are put into a reaction container to perform ester exchange and polycondensation reaction, so as to obtain an in-situ blended polydopamine nanosheet / furan-based polyester composite material. The method is simple in process, and the polydopamine nanosheet / furan-based polyester composite material prepared by the method has excellent mechanical property, gas barrier property and biodegradability.

The invention discloses reinforced high polymer modified asphalt and a preparation method thereof, and relates to the technical field of modified asphalt. The reinforced high polymer modified asphalt is prepared from the following raw materials in parts by weight: 100 parts of matrix asphalt, 4 to 6 parts of SBS (Styrene Butadiene Styrene), 0.3 to 0.6 part of cross-linking agent, 2 to 3.5 parts of plasticizer, 1 to 3 parts of anti-aging agent and 1.5 to 3 parts of nano filler, the preparation method comprises the following steps: reacting 2-formylphenylboronic acid with methanol to generate a dimethyl 2-formylphenylboronic acid compound; the preparation method comprises the following steps: reacting a 2-formylphenylboronic acid dimethyl ester compound with 1-amino-1-dodecanol to generate a boric acid ester-imine long-chain compound; and reacting the borate-imine long-chain compound with 3-glycidyl ether oxypropyl trimethoxy silane to generate the plasticizer. The reinforced high polymer modified asphalt prepared by the invention has good interface adhesion, high and low temperature stability (high-temperature deformation resistance and low-temperature crack resistance) and self-repairing performance.

The invention provides a preparation method of a high-covering yellow-phase quinacridone pigment. The preparation method comprises the following steps: step 1, using 116-118% of polyphosphoric acid; step 2, adding 2, 5-diphenylamino-3, 6-dihydroterephthalic acid dimethyl ester at the temperature of 90 DEG C to 135 DEG C; step 3, keeping the temperature at 120-135 DEG C for 1-4 hours, cooling to 120 DEG C, and diluting the polyphosphoric acid to 110-112%; step 4, pouring the polyphosphoric acid reactant into water, filtering, and washing with water to obtain 6, 13-dihydroquinacridone; step 5, adding the dried and crushed 6, 13-dihydroquinacridone into a solvent for pulping, and the concentration of the solvent must be greater than 50%; step 6, adding a sodium hydroxide solution, adjusting the pH value to be greater than 11, heating to 80-90 DEG C, and keeping the temperature for 30-60 minutes; step 7, after cooling, adding an oxidizing agent and a catalyst, determining that the pH value is greater than 11, heating to 100-110 DEG C, preserving heat for 2 hours, cooling and filtering to obtain the yellow-phase quinacridone with high coverage; the quinacridone obtained in the invention has excellent weather resistance and covering power, and can be used in printing pigments, water-based paint compositions, varnish, polyurethane varnish, plastic dispersions and spinning solutions; the obtained quinacridone is applied to synthesis and natural polymers, and the quinacridone obtained in the invention can be used in natural, recycled and synthetic fiber materials, and can also be mixed with gas organic and inorganic pigments for use.

The application discloses a synthesis method of N-chenodeoxycholyl-L-aspartic acid and application of the N-chenodeoxycholyl-L-aspartic acid in preparation of a medicine for improving metabolic associated fatty liver disease. The method provided by the application uses chenodeoxycholic acid and L-aspartic acid dimethyl ester hydrochloride as raw materials, synthesizes a chenodeoxycholic acid-aspartic acid dimethyl ester intermediate, and efficiently prepares a target compound, N-chenodeoxycholyl-L-aspartic acid, which is a novel structure, the compound exhibits a treatment effect superior to that of obeticholic acid (OCA) in an animal model, and can effectively improve multiple indexes such as liver steatosis, inflammation and fibrosis. The application provides a novel solution for major clinical challenges such as insufficient treatment effect, large side effect and rebound after drug withdrawal of current MAFLD treatment medicines, and provides a candidate compound with broad prospects for developing a new high-efficiency MAFLD treatment medicine.

The invention provides a carbonized resin decolorizing and refining method for mixed dibasic acid dimethyl ester, and belongs to the technical field of chemical separation and purification. According to the technical scheme, spherical carbonized resin formed by carbonizing styrene-divinyl benzene polymer resin is used as an adsorbent, and a colored crude product DBE is subjected to decoloration treatment through a fixed bed process. The carbonized resin has extremely high selective adsorption capacity and adsorption rate on colored impurities in DBE, the Pt-Co color number of the carbonized resin can be reduced from 50 or above to 10 or below, the decolorization rate exceeds 80%, and meanwhile the yield of the DBE product reaches 99% or above. And the resin saturated by adsorption is easy to regenerate and can be repeatedly used. The method is simple in process, efficient and environment-friendly, overcomes many defects of a traditional activated carbon decoloration method, and is particularly suitable for industrial refining production of DBE.

The invention discloses a dimethyl polyitaconate explosion suppression material, and belongs to the technical field of explosion suppressant preparation. The preparation method of the polyitaconic acid dimethyl ester comprises the following steps: uniformly mixing a dispersing agent, a surfactant and a solvent, then adding dimethyl itaconate (DMI) and an initiator, uniformly mixing, heating to react, and purifying to obtain the polyitaconic acid dimethyl ester. The polyitaconic acid dimethyl ester disclosed by the invention can play a physical inhibition role and a chemical inhibition role on combustion of dust, and has a very good explosion suppression effect.

The application relates to the technical field of organic synthesis, and particularly relates to a preparation method of omega-amino fatty acid methyl ester and long-chain nylon. The preparation method of the omega-amino fatty acid methyl ester specifically comprises the following steps: S1, ester exchange: long-chain dibasic acid dimethyl ester, methanol and a first organic solvent are mixed in the presence of a first catalyst, and the long-chain dibasic acid monomethyl ester is obtained through an ester exchange reaction; S2, ammonia addition: the long-chain dibasic acid monomethyl ester is used as a raw material, an amidation reaction is carried out, and then a reduction reaction is carried out to obtain the omega-amino fatty acid methyl ester, wherein n is greater than or equal to 8. The preparation method has the characteristics of a short process route and stable intermediates, can be suitable for batch production, and can also be suitable for continuous production.