734 results about "Butanedioic acid" patented technology

The invention discloses a nano blocking agent for drilling fluid and a preparation method thereof, and belongs to the technical field of blocking agents, the nano blocking agent for drilling fluid is prepared by reaction of a core layer blocking agent and a shell layer blocking agent, the core layer blocking agent is prepared by reacting nano silicon dioxide, gamma-methacryloxypropyltrimethoxysilane and a first part of vinylphosphonic acid, and has secondary blocking capability; and the shell blocking agent is prepared by reacting a second part of vinyl phosphonic acid, styrene and 2-dodecene-1-yl succinic anhydride, and has the characteristic of flexibility. The nano plugging agent has rigid supporting and flexible deformation capabilities, and the high-temperature stability and compressive strength of a plugging layer are remarkably improved. The chemical binding force of the plugging agent and the rock is enhanced; the hydrolysable methoxyl reserved in the core layer provides a secondary plugging function, and the plugging validity period is prolonged. The invention relates to a preparation method of a nano blocking agent for drilling fluid, which is used for preparing the nano blocking agent for drilling fluid.

The invention discloses a high-barrier antibacterial packaging material, a preparation method thereof and a packaging bag, and belongs to the technical field of packaging, the packaging material comprises the following raw materials by weight: 75-85 parts of polylactic acid, 15-25 parts of poly (butylene succinate), 2-6 parts of epoxidized urushiol, and 1-3 parts of benzyl quaternary ammonium salt modified montmorillonite; the epoxidized urushiol is prepared by carrying out epoxidation reaction on urushiol and organic peroxy acid; the packaging material further comprises the following raw materials: 2-5 parts of sepiolite fiber loaded magnesium oxide; according to the invention, biodegradable polylactic acid and poly (butylene succinate) are taken as base materials, and epoxidized urushiol is taken as a reactive compatilizer, so that the compatibility between polylactic acid and poly (butylene succinate) is improved, and meanwhile, the binding property between a polymer matrix and benzyl quaternary ammonium salt modified montmorillonite and sepiolite loaded magnesium oxide is enhanced; the packaging material with good mechanical property, barrier property and antibacterial property is obtained.

The invention discloses an enzyme response type KRAS targeted protein degradation chimera as well as a preparation method and application thereof, and belongs to the technical field of tumor targeted therapy. The enzyme response type KRAS targeted protein degradation chimera disclosed by the invention is obtained by covalently linking three parts, namely a KRAS targeted protein degradation chimera, an enzyme response type amino acid sequence and a cell penetrating peptide amino acid sequence, wherein the KRAS targeted protein degradation chimera is obtained by linking a KRAS targeted peptide and a VHL E3 ligase ligand through succinic acid. The enzyme response type KRAS targeted protein degradation chimera releases the KRAS targeted protein degradation chimera under the action of ATG4 enzyme shearing, and shows a relatively strong lung cancer resisting effect in vitro and in vivo. The invention has significant advantages in the aspect of antitumor drugs, and opens up a new field for the development of targeted protein degradation chimera drugs. Enzyme response type KRAS targeted protein degradation chimera molecular structural formula as follows: # imgabs0 #

The invention discloses a biodegradable polylactic acid composite material and a preparation method thereof, and relates to the technical field of polylactic acid materials. The method comprises the steps that firstly, chitosan activated through hydrochloric acid is subjected to graft modification through a KH550 silane coupling agent, meanwhile, nano-zinc oxide is subjected to surface modification through stearic acid, the chitosan and the nano-zinc oxide are mixed, spray drying is conducted, and antibacterial composite powder is prepared; the preparation method comprises the following steps: performing hydrochloric acid activation and KH570 silane coupling agent modification on nano silicon dioxide, performing hydroxypropylation modification on alkali lignin, and performing reflux crosslinking reaction on the modified alkali lignin, KH570 modified nano silicon dioxide, polycaprolactone, methyl methacrylate and azodiisobutyronitrile to prepare a heat-resistant reinforcer; uniformly mixing polylactic acid, poly (butylene succinate), the antibacterial composite powder, the heat-resistant reinforcer, tributyl citrate, polyethylene glycol and talcum powder, and extruding and granulating by using a twin-screw extruder to obtain the heat-resistant antibacterial material. The composite material prepared by the invention has excellent antibacterial property, heat resistance and biodegradability.

The invention relates to the technical field of welding materials, and discloses washable semiconductor solder paste and a preparation method and application thereof. The washable semiconductor solder paste comprises scaling powder and tin powder, wherein the mass ratio of the scaling powder to the tin powder is 1: (8-9.6); the soldering flux comprises the following raw material components: a film-forming agent, composite organic acid, a thixotropic agent, a surfactant, an antioxidant and a solvent, wherein the composite organic acid is composed of succinic acid and glutaric acid according to the mass ratio of (1-3): (1-2.5). According to the washable semiconductor solder paste, the particle size, the melting point and the alloy components of the tin powder are controlled, composite organic acid composed of succinic acid and glutaric acid in a specific proportion is adopted in the soldering flux, and other components are matched with one another; the tin powder and the soldering flux in a specific mass ratio are combined, so that the prepared washable semiconductor solder paste is good in wettability, the expansion rate is larger than or equal to 85%, the storage life reaches 3 months, and the washable semiconductor solder paste can be directly cleaned with water after being welded and is high in corrosion resistance and oxidation resistance.

The invention relates to the field of coatings, and discloses a biomass-based oil-resistant coating and a preparation method thereof, the coating comprises an additive solution, a paraffin solution and gallic acid; the paraffin solution is obtained by dissolving paraffin in absolute ethyl alcohol; a preparation method of the additive solution comprises the following steps: mixing chitosan powder and an acetic acid aqueous solution to prepare a chitosan solution, ultrasonically dispersing functionalized montmorillonite in deionized water to prepare a suspension, then uniformly mixing the chitosan solution and the suspension, adding modified phytic acid prepared by grafting phytic acid and ethylene glycol diglycidyl ether, and stirring to react; the functional montmorillonite is prepared by modifying modified montmorillonite with titanium dioxide and zinc oxide, then activating the modified montmorillonite with 3-aminopropyltriethoxysilane and succinic anhydride, and then carrying out a ring-opening reaction with glycidyl neodecanoate. The coating prepared by the invention has high water resistance, the Kit oil-proof grade is kept at grade 12, and the oil-proof performance of the coating is greatly improved. Meanwhile, the antibacterial performance, the tensile index and the ultraviolet aging resistance are relatively high.

The invention relates to the technical field of in-vitro diagnostic kits, in particular to carboxyl polystyrene microspheres, a preparation method and application of the carboxyl polystyrene microspheres in a kit for quantitatively detecting MxA. The preparation method of the carboxyl polystyrene microspheres comprises the steps that firstly, polystyrene microspheres with the surface rich in aldehyde groups are prepared through a soap-free emulsion polymerization method; then carrying out a Schiff alkali reaction with 2-aminoethyl methacrylate hydrochloride to carry out double bond modification on the surface of the microsphere, and meanwhile, improving the hydrophilicity of the microsphere by an ester group and an imino group; and finally, carrying out sulfydryl-double bond addition reaction on the polystyrene microspheres and mercaptosuccinic acid to generate the polystyrene microspheres rich in carboxyl on the surfaces. The carboxyl polystyrene microspheres prepared by the invention can improve the binding efficiency of latex and an MxA antibody, so that the detection sensitivity is improved, the purpose of high-sensitivity quantitative detection of MxA protein can be achieved, and the detection time is greatly shortened.

The present disclosure relates to a biodegradable multilayer film comprising stacked on each other in the following order: a) a first outer layer comprising a first polymer selected from the group consisting of poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), poly (butylene succinate-co-adipate) (PBSA), and mixtures thereof; b) a core layer comprising a blend of thermoplastic starch (TPS) and polybutylene adipate terephthalate (PBAT); c) a second outer layer comprising a second polymer selected from the group consisting of poly (butylene adipate-co-terephthalate) (PBAT), poly (butylene succinate) (PBS), poly (butylene succinate-co-adipate) (PBSA), and mixtures thereof. The present disclosure also relates to a disposable bag, a bioreactor and a container suitable for mixing, packaging, storing or transporting biopharmaceutical substances, wherein the disposable bag, bioreactor and container comprise the biodegradable multilayer film.

The invention relates to the technical field of analysis and detection, in particular to a fluorescent switch sensor based on quantum dot-nano porphyrin and application. The specific technical scheme is as follows: the fluorescent switch sensor is constructed by utilizing cadmium telluride quantum dots modified by mercaptosuccinic acid and a 5, 10, 15, 20-tetra (4-nitrophenyl) porphyrin nano material modified by a cationic surfactant hexadecyl trimethyl ammonium bromide. And the method has a good enrichment effect on zearalenone. The sensor has high sensitivity, high selectivity and anti-interference performance, can accurately analyze trace zearalenone in actual grain samples (corn, rice, soybean and the like), and has the advantages of simplicity in operation, low detection limit, high sensitivity, low cost and the like.

The invention discloses environmentally degradable plastic as well as a preparation method and application thereof, and belongs to the technical field of degradable plastic. The degradable modified plastic is prepared from the following raw materials: polylactic acid, poly (butylene terephthalate)-adipate, modified thermoplastic starch, modified cellulose, poly (butylene succinate), epoxidized soybean oil, polyvinyl alcohol, glycerol monolaurate and ethylenediaminetetraacetic acid. Wherein the modified thermoplastic starch is obtained by thermoplastic modification of starch through a plasticizer and modification of castor oil and toluene diisocynate; the modified cellulose is obtained by modifying cellulose acetate with chitosan. By regulating and controlling the types and proportions of the raw materials for preparing the plastic, the plastic with excellent degradation performance and mechanical performance can be obtained, the shopping bag is prepared from the plastic, the loading capacity can be remarkably improved, the plastic is easily degraded by microorganisms in the environment after being discarded, and environmental pollution is avoided.

The invention discloses a poly (butylene succinate) composite fiber and a preparation method thereof. The preparation method comprises the following steps: 1) dissolving the photochromic dye, the antioxidant A and the ultraviolet light absorber in an oil-soluble solvent to obtain an oil-phase solution; 2) adding the oil phase solution into an aqueous solution containing an emulsifier, and emulsifying to obtain an oil-in-water emulsion; adjusting the pH value of the emulsion to 3-8 and the temperature to 20-100 DEG C; (3) adding a capsule wall material and a magnetic substance into water, adding the mixture into the emulsion at a constant speed, putting the mixture into an external magnetic field with controllable strength, and keeping the temperature at 20-90 DEG C for 0.3-5 hours to obtain the photochromic microcapsule with a shell with a special structure; and 4) adding the photochromic microcapsule into a spinning solution of the poly (butylene succinate) fiber, and then spinning to obtain the poly (butylene succinate) composite fiber.

The invention relates to the field of textile materials, and discloses a multi-thread elastic knitted fabric and a preparation method thereof.The multi-thread elastic knitted fabric is prepared from, by weight, 30 parts of ternary polymerization elastic fibers; 70 parts of modified bamboo fiber; the ternary copolymerized elastic fiber is prepared from the following raw material components in parts by weight: 28-32 parts of polylactic acid; 38 to 42 parts of polytrimethylene terephthalate; 28 to 32 parts of poly (butylene succinate); 1 to 3 parts of graphene nanosheets; 0.5 to 1.5 parts of epoxidized soybean oil; 2 to 4 parts of beta-cyclodextrin; the modified bamboo fibers are subjected to enzymatic treatment, silane coupling agent modification, dopamine coating treatment and ultrasonic treatment. Through micro gradient structure design and multi-step functionalization treatment of the ternary polymerization elastic fibers and the modified bamboo fibers, unification of excellent elastic recovery, comfort, multifunctionality and durability is achieved.

The invention provides an epoxidized soybean oil-binary acid bio-based dynamic polymer, a preparation method thereof and a paper-based strain sensor packaged by the epoxidized soybean oil-binary acid bio-based dynamic polymer. The preparation method of the dynamic polymer comprises the following steps: (1) taking epoxidized soybean oil as an epoxy monomer, aliphatic dibasic acid as a flexible monomer and aromatic dibasic acid as a rigid monomer, and carrying out polymerization reaction in the presence of a transesterification catalyst to obtain a dynamic polymer prepolymer; the aliphatic binary acid comprises succinic acid, adipic acid and sebacic acid; (2) removing bubbles from the dynamic polymer prepolymer; and (3) carrying out thermal curing on the dynamic polymer prepolymer to obtain the epoxidized soybean oil-binary acid bio-based dynamic polymer. The epoxidized soybean oil-binary acid bio-based dynamic polymer has good mechanical properties and hydrophobicity, a paper-based strain sensor based on the epoxidized soybean oil-binary acid bio-based dynamic polymer also has good mechanical properties and hydrophobicity, and the sensor has certain application potential in the field of human motion monitoring.

The invention relates to the technical field of plugging materials, and provides a low-temperature temporary plugging agent for fracturing and a preparation method thereof. The low-temperature temporary plugging agent for fracturing is prepared from the following raw material components: polycaprolactone, polylactic acid, polyglycolic acid, poly (butylene succinate), triglycidyl isocyanurate and silicon dioxide. The silicon dioxide comprises silicon dioxide A and silicon dioxide B; the silicon dioxide A is nano silicon dioxide; the silicon dioxide B is nano silicon dioxide composite micron silicon dioxide. Through the technical scheme, the problem of low strength of the low-temperature temporary plugging agent in related technologies is solved.

The invention relates to the technical field of high polymer materials, and discloses a preparation method of a modified master batch degradable material and application of the modified master batch degradable material in a packaging lunch box, and the modified master batch degradable material comprises the following components by mass: 75.0-93.8 parts of poly (butylene succinate); 5.0 to 20.0 parts of aliphatic series-aromatic copolyester; 1.0 to 4.0 parts of 1, 1 '-methylenebis-4, 1-phenylene-bismaleimide, and 1.0 to 4.0 parts of 1, 1'-methylenebis-4, 1-phenylene-bismaleimide; 0.5 to 2.0 parts of talcum powder; the method comprises the following steps: mixing dried poly (butylene succinate), aliphatic-aromatic copolyester, bismaleimide and talcum powder, performing reactive extrusion and melt mixing through a twin-screw extruder, and then cooling, pelletizing and drying the extrudate. Through specific components and a reactive extrusion process, a dynamic cross-linked network is formed by utilizing a Diels-Alder reaction, and the modified master batch degradable material of which the comprehensive mechanical property and the heat resistance are remarkably improved is prepared.

The invention relates to formic acid solder paste with the ultralow air hole rate and a preparation method and application of the formic acid solder paste. The solder paste is prepared from, by mass, 85%-90% of alloy welding powder and 10%-15% of scaling powder. The soldering flux comprises the following raw materials in parts by weight: 5-10 parts of an activating agent, 1-5 parts of a rheological agent, 30-40 parts of an organic solvent, 20-30 parts of a paste forming agent, 3-5 parts of a surfactant and 0.1-0.5 part of a corrosion inhibitor, and the surfactant is a composition of a lauryl amphoteric imidazoline surfactant, iso-tridecanol polyoxyethylene ether and N-vinyl caprolactam. The activating agent is a composition of ricinoleic acid, ethylenediaminetetraacetic acid and ammonium succinate. The surface active agent and the activating agent in the soldering flux have a synergistic effect, so that the cleanliness of the welding surface and the soldering flux is ensured, the wettability and the flowability are improved, cavities are reduced, the soldering flux is uniformly spread and filled, high-quality welding spots are formed, and the voidage of solder paste is remarkably reduced.

The invention discloses a modified polylactic acid composite material and application thereof. The modified polylactic acid composite material comprises the following raw materials in percentage by weight: 15-50% of polylactic acid; 15 to 50% of poly (butylene succinate); 15 to 50% of poly (butylene adipate-co-terephthalate); 1-5% of a compatibilizer; 0.1-1% of an antioxidant; 0.1-5% of a release agent; 0.1-1% of a melt flow regulator; 0.1-5% of a nucleating agent; 0.1-1% of an anti-hydrolysis agent; wherein the compatibilizer comprises an elastomer containing an epoxy group, an elastomer containing a maleic anhydride group, an ethylene-methyl acrylate random copolymer and an ethylene-butyl acrylate copolymer, and the weight ratio of the elastomer containing the epoxy group to the elastomer containing the maleic anhydride group is 1: 4-4: 1. The modified polylactic acid composite material has good fluidity and mechanical properties, and is suitable for preparing the cable tie by adopting an injection molding mode.

The invention belongs to the technical field of degradable and high-barrier modified plastics, and particularly relates to an environment-friendly, high-oxygen-barrier and water-resistant modified plastic, a plastic alloy and a functional product of the environment-friendly, high-oxygen-barrier and water-resistant modified plastic and the plastic alloy. According to the material, polyvinyl alcohol is used as a main component and is blended with auxiliaries such as a plasticizer and a cross-linking agent through a twin-screw melt extrusion technology, and modified plastic (HB-PVOH) with excellent barrier property, water resistance and mechanical property is formed. In order to further enhance the performance, the HB-PVOH can be co-extruded with polymers such as polyhydroxyalkanoate, polymethyl ethylene carbonate, polylactic acid, poly (butylene succinate) and the like to prepare binary or ternary plastic alloy. The material can be widely applied to the fields of high-end packaging, oxygen barrier coatings, environment-friendly packaging and the like, plastic or paper-plastic composite products are prepared through a multi-layer co-extrusion-film blowing, curtain coating or film spraying technology, the sustainable development trend of aluminum reduction, plastic reduction and fluorine reduction is met, and the material is a green packaging solution which is high in cost performance, environmentally friendly and practical.

The invention provides a method for separating and extracting bio-based succinic acid from fermentation liquor, which comprises the following steps: (1) enabling the fermentation liquor to sequentially pass through a ceramic membrane and a nanofiltration membrane, and decoloring to obtain bio-based succinic acid decolored liquor; (2) sequentially carrying out ion exchange impurity removal and concentration treatment on the bio-based succinic acid decoloring solution to obtain a bio-based succinic acid concentrated solution; and (3) carrying out multi-stage cooling crystallization on the bio-based succinic acid concentrated solution to obtain the bio-based succinic acid, the multi-stage cooling crystallization comprises first-stage crystallization, second-stage crystallization and third-stage crystallization which are carried out in sequence. Through the steps of integrated membrane filtration, decoloration, ion exchange, concentration, multi-stage crystallization and the like, thalli, proteins, pigments, inorganic ions and other impurities in fermentation liquor can be efficiently removed, so that a high-purity bio-based succinic acid product is obtained, meanwhile, the product yield is increased, and energy consumption and waste discharge are reduced.

The invention relates to an electrocatalysis-biological fermentation coupling system as well as a construction method and application thereof. The electrocatalysis-biological fermentation coupling system comprises an electrocatalysis unit and a fermentation unit; the electro-catalysis unit is used for electrolyzing water to generate H2 and O2; the fermentation unit is used for producing succinic acid through fermentation by taking CO2 as a carbon source and taking H2 and O2 generated by the electro-catalysis unit as an electron donor and an electron acceptor; the fermentation unit comprises S.ovaata bacteria, E.coli bacteria and a culture medium, the S.ovaata bacteria are used for synthesizing acetate by taking CO2 as a carbon source, and the E.coli bacteria are used for synthesizing succinic acid by utilizing the acetate. According to the invention, an electro-catalysis-biological fermentation coupling system with a specific structure is designed, the system can stably operate for 5 days, and the average yield of succinic acid is as high as 30.70 mg.L <-1 >. Day <-1 >.

The invention relates to the technical field of mineral cables, and provides a mineral fireproof power cable which sequentially comprises a cable core, a mineral insulating layer, a copper sheath and an outer sheath layer from inside to outside, and the outer sheath layer is prepared from the following raw materials in parts by weight: 95-105 parts of polyethylene, 4-6 parts of a plasticizer, 30-35 parts of composite titanium dioxide, 1-2 parts of an antioxidant and 5-8 parts of a flame retardant; the composite titanium dioxide is titanium dioxide treated by butanedioic anhydride and phthalic anhydride. According to the technical scheme, the problem of poor tensile strength of the polyethylene outer sheath layer of the mineral fireproof power cable in the prior art is solved.

The invention belongs to the technical field of packaging materials, and particularly relates to a packaging material with antibacterial activity and a preparation method thereof. The packaging material with antibacterial activity is prepared from the following raw materials in parts by weight: 60 to 70 parts of polylactic acid, 10 to 20 parts of poly (butylene succinate), 3 to 5 parts of modified montmorillonite, 0.5 to 1 part of a bacteriostatic agent, 0.5 to 1 part of a lubricating agent, 1 to 3 parts of a compatilizer and 1 to 1.5 parts of functional filler. The packaging material provided by the invention has excellent barrier property, antibacterial property and mechanical property, stable fixation and synergistic interaction of functional components such as the modified montmorillonite and the functional filler are realized, and the packaging material has important significance in promoting technical progress of the packaging industry and meeting the requirements of the market on high-performance packaging materials.

The invention provides an aerogel-based submarine cable material as well as a preparation method and application thereof.The submarine cable material is prepared from the following raw materials in parts by weight: 10-20 parts of modified aerogel, 20-25 parts of high-density polyethylene, 6-10 parts of a styrene-maleic anhydride copolymer, 4-6 parts of 2, 7-anthraquinone ethanesulfonic acid and 5-7 parts of modified poly (butylene succinate), 2 to 4 parts of acetyl triethyl citrate; the modified aerogel is prepared from silane modified aerogel and sulfydryl modified aerogel in a mass ratio of 1: (1-3). By compounding the raw materials, the comprehensive performance of the cable material is comprehensively improved, so that the cable material has excellent light weight, pressure resistance, low temperature resistance, corrosion resistance, flexibility, aging resistance and chemical stability, has good environmental adaptability, prolongs the service life of a cable in an extreme seabed environment, and has good social use value.

The invention discloses a comprehensively degradable mulching film and a preparation method thereof, and relates to the field of agricultural biodegradable materials. The mulching film is prepared from polylactic acid, poly (butylene succinate), polycaprolactone, acetylated starch, nano cellulose whiskers and auxiliaries through vacuum drying, high-speed premixing, twin-screw extrusion granulation, film blowing forming and aging treatment. In the preparation process, by regulating and controlling the proportion of the polylactic acid base material, the substitution degree of the acetylated starch and the addition amount of the nanocellulose whiskers, a polymer-bio-based additive-nano reinforcement synergistic effect system is constructed, and optimal balance of the mechanical property and the biodegradation efficiency of the mulching film is achieved. The mulching film capable of being comprehensively degraded is suitable for the field of agricultural covering, can be completely degraded through the synergistic effect of microbial degradation and photooxidative degradation in the natural environment, solves the problem of residual pollution of a traditional mulching film, and meanwhile meets the mechanical supporting requirement in the crop growth period.

The invention discloses a low-cost polyester degradable plastic garbage bag and an extrusion blow molding process thereof. The garbage bag is prepared from a composite material with a specific formula comprising poly (butylene succinate) (PBS), polylactic acid (PLA), surface-modified nano calcium carbonate, a degradation aid, a compatilizer and an anti-blocking agent. The key of the preparation process is as follows: deep drying pretreatment of raw materials; uniform dispersion and compatibility of all the components are realized through high-speed mixing and twin-screw melt blending granulation; a single-screw extrusion film blowing machine provided with an internal cooling (IBC) system is adopted, and stable forming of film bubbles and preparation of an ultrathin film are achieved under the condition that the temperature, the blow-up ratio and the traction speed are accurately controlled. Through collaborative innovation of a material formula and a process, the technical problems that an existing degradable garbage bag is high in cost, insufficient in mechanical property, poor in processing stability, uncontrollable in degradation behavior and the like are successfully solved.

The invention relates to an electroplated coating protective agent and a preparation method thereof, and belongs to the technical field of electroplated coating protective agents, and the protective agent comprises the following raw materials: main salt, auxiliary salt, a composite complexing agent, 1-docosanethiol, a sealing agent, absolute ethyl alcohol and deionized water. The succinic acid, the N-sodium lauroyl sarcosinate and the citrazinic acid are used as the composite complexing agent, and starting from different aspects of activating the surface of the coating, accelerating the growth of the protective film layer and increasing the compactness of the protective film layer, the prepared protective agent can effectively improve the corrosion resistance effect of the coating; and the added 1-docosanethiol is used for reducing the defect area of the protective film layer and further effectively improving the corrosion resistance of the protective film. Besides, chromic nitrate is used as a main salt, cerous sulfate and sodium molybdate are used as auxiliary salts, and sodium silicate is used as a sealing agent, so that the prepared protective agent can effectively have remarkable salt spray resistance, and meanwhile, the appearance quality of a formed film layer can also be improved.

The invention provides a method for continuously preparing succinic anhydride through maleic anhydride hydrogenation, which comprises the following steps: inputting dissolved maleic anhydride and a solvent from the upper part of a reactor, and carrying out reverse contact reaction with hydrogen input from the lower part of the reactor; the reaction mixture sequentially passes through a trickle bed reaction section, a cooling section and a bubbling bed reaction section from top to bottom, and a succinic anhydride crude product is output from the bottom of the reactor; separating and purifying the succinic anhydride crude product to obtain a succinic anhydride product; wherein the cooling section is a falling film cooling section. According to the reactor, heat released by the trickle bed reaction section is timely removed through falling film cooling, meanwhile, the solubility of hydrogen is improved, a liquid phase is used as a continuous phase in the bubbling bed reaction section to promote maleic anhydride to fully react, and the reaction temperature is controlled within a proper range; the whole process is simple and convenient to operate, the raw material conversion rate and the product selectivity are improved, the process energy consumption is saved, and the service life of the catalyst is prolonged.

The invention relates to the technical field of high polymer materials, in particular to a degradable PHA tableware material and a preparation method thereof. The degradable PHA tableware material overcomes the problem that the degradable PHA tableware material is poor in mechanical property and antibacterial property. The preparation method comprises the following steps: drying polyhydroxyalkanoate, poly (butylene succinate), acetylated lignin, nano-zinc oxide, chitosan oligosaccharide and hexagonal boron nitride, carrying out melt extrusion on the dried materials, maleic anhydride grafted PHA, acetyl tributyl citrate and cinnamyl aldehyde in a double-screw extruder, carrying out injection molding, and carrying out plasma treatment activation. Polyurethane antibacterial slurry containing silver-loaded zeolite is sprayed, the tableware material with the body-surface synergistic enhancement function is finally obtained, and the impact strength, rigidity and antibacterial rate of the material are improved.

The invention discloses a genetically engineered bacterium for high yield of L-alanine as well as a construction method and application of the genetically engineered bacterium, a dominant strain is obtained by knocking out an alanine racemase gene dadX and integrating coding sequences of alanine dehydrogenase from different sources, and the shake flask yield is 10.8 g / L; the activity of a corresponding mutant M18L / E75A / A78S / I266V is 4.3 times that of a wild type; 6 by-product related genes are knocked out, meanwhile, a multi-copy strain integrated with alanine dehydrogenase is constructed, and the yield of E.coli A-LB6 in a 5L fermentation tank is increased to 133.3 g / L. Through a dynamic regulation and control strategy, an oxygen-sensitive promoter Pomp * is adopted to replace a phosphoenolpyruvate carboxylase promoter, so that succinic acid byproducts are reduced by 85.8%, and the yield reaches 143.5 g / L after 48 hours of aerobic and anaerobic two-stage fermentation. And finally, by regulating and controlling the ATP synthetase gene cluster atp promoter, the yield of L-alanine in a 50 L fermentation tank reaches 151.3 g / L, and the saccharic acid conversion rate reaches 95.2%. The combination of polygene knockout and dynamic metabolism regulation effectively enhances the biosynthesis ability of alanine, and provides an efficient engineering strain for industrial production.

The invention discloses a limestone-gypsum wet flue gas desulfurization composite synergist and a preparation method thereof, and relates to the technical field of flue gas desulfurization. The limestone-gypsum wet flue gas desulfurization composite synergist is prepared from the following raw materials in parts by weight: 15 to 18 parts of organic acid, 5 to 8 parts of oxidation catalyst, 8 to 10 parts of sodium salt, 5 to 10 parts of magnesium salt, 12 to 15 parts of surfactant, 5 to 8 parts of organic acid alkali metal salt and 4 to 5 parts of dispersing agent. The preparation method comprises the following steps: reacting 2-dodecene-1-yl succinic anhydride with N, N-dimethyl ethylenediamine to generate a monoamide compound, reacting the monoamide compound with epoxy chloropropane to generate a quaternary ammonium salt compound, and reacting the quaternary ammonium salt compound with sodium sulfanilate to generate the surfactant. The limestone-gypsum wet flue gas desulfurization composite synergist prepared by the invention can promote dissolution of calcium carbonate, and shows good desulfurization efficiency.