666 results about "Acetic anhydride" patented technology

The invention discloses an acetic anhydride production waste gas neutralization treatment device and method, and relates to the technical field of waste gas neutralization treatment.The acetic anhydride production waste gas neutralization treatment device comprises a treatment tank, a gas inlet pipe is fixedly installed at the bottom of the treatment tank, gas holes are formed in the surface of the gas inlet pipe, and a gas outlet pipe is fixedly installed at the top of the treatment tank; the waste gas neutralizing device is arranged in the treatment tank, and the waste gas neutralizing device comprises a motor, a connecting pipe, a fixing frame, a water spraying pipe, a reciprocating screw rod, a threaded plate, a fixing rod, an elastic telescopic rod, an activated carbon plate, a long rod, a universal wheel and an elastic telescopic scraper plate; the reciprocating lead screw rotates to drive the elastic telescopic rod to rotate, the elastic telescopic rod rotates to drive the activated carbon plate to rotate, through rotation of the activated carbon plate, the plate face can make uniform contact with pollutants in waste gas, saturation and aging of a local area are avoided, and the adsorption efficiency of activated carbon is improved.

The invention relates to the technical field of CO2 miscible-phase oil displacement, in particular to an ester gas-soluble surfactant for reducing CO2 miscible-phase pressure and a preparation method and application thereof.The ester gas-soluble surfactant is prepared from polyglycerol fatty acid ester and acetic anhydride, the ester gas-soluble surfactant contains unsaturated hydrocarbon chains with the carbon atom number being 8-18, and the unsaturated hydrocarbon chains are connected with the polyglycerol fatty acid ester. N is the polymerization degree of the polyglycerol fatty acid ester, n is any integer in the range of 2-22, and the ester gas-soluble surfactant has the solubility of 0.5 wt%-1.5 wt% in supercritical carbon dioxide. When the ester gas-soluble surfactant provided by the invention is used, other auxiliaries do not need to be added, and a good mixing reduction effect can be achieved aiming at different crude oils by adjusting the number of carbon dioxide-philic groups and the length of oleophylic unsaturated hydrocarbon chains.

The invention relates to the technical field of starch processing, in particular to a preparation method and application of modified starch, and the modified starch is prepared from the following raw materials in parts by mass: 15-30 parts of pre-modified starch A and 55-70 parts of pre-modified starch B; the pre-modified starch A is prepared from pretreated starch A, acetic anhydride and acetaldehyde dehydrogenase; the pretreated starch A is frozen ball-milled starch; the pre-modified starch B is prepared from pre-treated starch B and octenyl succinic anhydride; the pretreated starch B is step-by-step toughened starch; the step-by-step toughening treatment comprises the following steps: performing low-temperature sealing treatment on starch, performing short-time ultrasonic treatment, performing heating reaction, performing secondary ultrasonic treatment, performing high-temperature treatment, and performing secondary ultrasonic treatment; the pre-modified starch A and the pre-modified starch B are mixed according to a specific proportion, and the modified starch which is high in solubility and freeze-thaw stability and can be widely applied to the fields of food, papermaking, spinning and medicine is obtained.

The invention provides a method for recovering waste etching liquid containing phosphoric acid, acetic acid and nitric acid, which comprises the following steps: carrying out reduced pressure distillation on the waste etching liquid under a reduced pressure condition, distilling and condensing light components of nitric acid and acetic acid to obtain mixed acid liquor of acetic acid and nitric acid, and detecting the content of nitric acid, acetic acid and water in the mixed acid liquor; adding sodium hydroxide or potassium hydroxide and the like into mixed acid liquor of acetic acid and nitric acid, so that all nitric acid in the mixed acid liquor generates nitrate; and adding acetic anhydride into the acetic acid-containing mixed solution, fully reacting, filtering the separated salt, adding an extracting agent into the filtrate, and collecting the high-purity acetic acid. According to the method, phosphoric acid, acetic acid and nitrate in the waste etching liquid are recycled, the recycled acetic acid is high in purity, high in recycling rate and high in operability, large-scale production can be met, resource recycling is achieved to the maximum extent, direct emission of non-phosphorus resources of the waste etching liquid is avoided, and resource waste and environmental pollution are avoided.

The invention relates to the technical field of polyimide films, in particular to a PI film and a preparation method thereof. The PI film comprises the following raw materials in parts by mass: 100-150 parts of soluble polyimide resin, 5-15 parts of biphenyl epoxy resin, 5-10 parts of activated titanium dioxide, 1-5 parts of a curing agent and 1-3 parts of a curing accelerator, the soluble polyimide resin comprises the following raw materials in parts by mass: 5-10 parts of a first monomer, 25-30 parts of a second monomer, 50-60 parts of a third monomer, 20-30 parts of acetic anhydride and 5-15 parts of triethylamine. The size stability and heat resistance of the film can be remarkably improved, meanwhile, the outstanding transparency of the polyimide film can be guaranteed, and the application of the film in the field of flexible display is met.

The invention provides an acetylated surfactant capable of reducing the minimum miscible pressure of CO2 miscible displacement as well as a preparation method and application of the acetylated surfactant, and belongs to the technical field of CO2 oil displacement. The preparation method of the acetylated surfactant comprises the following steps: reacting a gluconic acid aqueous solution with n-caprylic alcohol under the action of a catalyst A to obtain n-octyl gluconate; under the action of a catalyst B, n-octyl gluconate and acetic anhydride react to obtain the acetylated surfactant for reducing the minimum miscible pressure of CO2 miscible flooding. The preparation method of the surfactant is simple, and the raw materials are cheap, wide in source, green and low in cost; the obtained surfactant can interact with CO2, has high CO2 affinity, and can effectively reduce the minimum miscible pressure of CO2 miscible flooding.

The invention discloses a sodium alginate embedded iron-carbon microcapsule material for repairing cadmium and arsenic polluted soil and a preparation method of the sodium alginate embedded iron-carbon microcapsule material, and belongs to the technical field of soil heavy metal pollution repairing materials. The material comprises straw biochar, high-iron steel slag powder, a sulfydryl acetylated chitosan-iron monatomic cluster compound, a boron-doped graphitized carbon coated cobalt ferrite nanosheet, sodium alginate, calcium chloride and sodium carbonate. Wherein the sulfydryl acetylated chitosan is prepared by reacting chitosan with sulfydryl acetic anhydride, dialyzing and drying, and performing solvothermal reaction with ferric nitrate under high pressure. The preparation method comprises the following steps: pyrolyzing and drying the straw biochar, reacting the high-iron steel slag with sulfuric acid, adding the biochar, adjusting the pH value, adding sodium carbonate, mixing to obtain an iron-carbon-based passivation material, mixing with two modified compounds, mixing with a sodium alginate solution, dropwise adding a calcium chloride solution, and stirring and curing. The material can be applied to remediation of cadmium and arsenic polluted soil.

The invention discloses a preparation method of magnesium acetyltaurine salt, which comprises the following steps: S1, dissolving taurine in water to react with strong base, and concentrating water to obtain corresponding taurine salt; s2, dispersing the taurine salt obtained in the step S1 in acetic acid to react with acetic anhydride, and concentrating the acetic acid to obtain corresponding acetyl taurine salt; and S3, dissolving the acetyl taurine salt obtained in the step S2 in water, adding magnesium salt, adjusting the pH value of a reaction system, adding a single post-treatment solvent, crystallizing, filtering, and drying to obtain the acetyl taurine magnesium salt. According to the preparation method of the magnesium acetyltaurate, provided by the invention, the dosage of acetic anhydride and a post-treatment solvent is effectively reduced, the generation of acid-containing wastewater can be remarkably reduced, the process is simple, the reaction is mild, the raw materials are cheap and easy to obtain, the yield is high, and large-scale industrial production is facilitated.

The invention discloses a method and device for intelligently monitoring the content of acetic anhydride, and relates to the technical field of acetic anhydride monitoring. An L-shaped fixing plate is arranged at the top of the base, a solvent tank is arranged in the L-shaped fixing plate, a feeding pipe is arranged on the left side of the solvent tank, a circulating pump is arranged on the right side of the top of the base, the left side of the circulating pump communicates with the solvent tank through a straight pipe, a circulating pipe is arranged between the top of the circulating pump and the solvent tank, and a refraction assembly is arranged in the L-shaped fixing plate. The stirring net plate is used for stirring and mixing a bottom solution and a top solution of the solvent tank, the precipitation phenomenon of acetic anhydride components in the long-term storage process is prevented, and the situation that the acetic anhydride content of the solution at different depths is different, and then the acetic anhydride content detection effect is affected is avoided.

The invention relates to the technical field of polyimide fibers, in particular to a method for preparing polyimide fibers of different color systems based on in-situ coloring, which comprises the following steps: carrying out condensation polymerization on perylene tetracarboxylic dianhydride compounds or perylene diimide, diamine monomers and dianhydride monomers to obtain a polyamide acid solution; adding acetic anhydride and pyridine into the polyamide acid solution for chemical ring-closure reaction to obtain a polyimide solution; and carrying out wet spinning on the obtained polyimide solution to obtain the colored polyimide fiber. The method for preparing the polyimide fibers of different color systems based on in-situ coloring is simple in process and environmentally friendly, and the prepared polyimide fibers of different color systems are high in color fastness and excellent in mechanical property.

The invention discloses a propolis extract-loaded sprayable bifunctional gel as well as a preparation method and application thereof. The preparation method comprises the following steps: synthesizing acetylated carboxymethyl chitosan by taking carboxymethyl chitosan and acetic anhydride as raw materials; the preparation method comprises the following steps: reacting acetylated carboxymethyl chitosan and aminophenylboronic acid serving as raw materials to synthesize a boric acid modified acetylated carboxymethyl chitosan gel precursor; the preparation method comprises the following steps: blending a boric acid modified acetylated carboxymethyl chitosan gel precursor with water, and self-assembling into A-CC-PBA hydrogel under the action of a hydrogen bond and a pi-pi bond; and adding the propolis extract into the A-CC-PBA hydrogel, so as to obtain the A-CC-PBA hydrogel. The gel prepared by the invention has good adhesion performance, can stably retain in the local part of the oral ulcer and can realize efficient targeted recognition and slow release of drugs to realize efficient sterilization and long-acting anti-inflammatory effects, the curative effect on the oral ulcer is obviously improved, and a new preparation type is provided for oral mucosa administration.

The invention discloses a preparation method of an H beta molecular sieve catalyst, which comprises the following steps: carrying out acid-base alternate etching on a roasted H beta molecular sieve according to an acid-base sequence by adopting an acid-base alternate etching method, and optionally carrying out ion exchange and roasting on a product obtained after alkali etching to obtain the H beta molecular sieve catalyst. According to the method disclosed by the invention, the H beta molecular sieve is modified through acid-base alternate etching, so that not only is abundant binary micro / mesopores constructed, the specific surface area of the molecular sieve increased and the mass transfer effect enhanced, but also the required acid strength and appropriate L and B acid sites are provided by changing the acid strength and the acid type on the pore channel and the surface of the catalyst subjected to acid-base etching. The prepared H beta molecular sieve catalyst is applied to Friedel-Crafts acylation reaction of anisole and acetic anhydride, and the catalytic activity is remarkably improved.

The invention relates to the technical field of acetic anhydride content optical detection, in particular to an acetic anhydride content optical detection device and method.The acetic anhydride content optical detection device comprises a detection box, a cleaning seat is fixedly connected into the detection box, a squeezing plate is fixedly connected into the cleaning seat, a scrubbing mechanism is rotatably connected to the squeezing plate, and a wiping ring is arranged in the cleaning seat; the bottom of one side of the detection box is fixedly connected with the exhaust hood in a penetrating manner, the inner wall of the detection box is rotatably connected with the push-pull mechanism, the box cover is arranged above the detection box, and the Fourier transform infrared spectrometer is fixedly arranged on the inner wall of one side of the detection box. The outer wall of the light-transmitting tube type liquid pool is automatically cleaned, fingerprints can be effectively removed, it is ensured that an optical path is not interfered, light rays are prevented from being scattered or absorbed when passing through the light-transmitting tube type liquid pool, and the accuracy, efficiency, repeatability and consistency in the experiment process can be greatly improved.

The invention provides low-dielectric and high-heat-resistance adamantane type maleimide resin as well as a preparation method and application thereof, and belongs to the technical field of synthetic resin for electronic materials. The preparation method comprises the following steps: S1, dissolving an adamantane type amino compound to obtain a solution A; dissolving maleic anhydride to obtain a solution B; s2, dropwise adding the solution A into the solution B; s3, acetic anhydride and a catalyst are added into the solution obtained after the stirring reaction in the step S2, then the temperature is increased to 90-110 DEG C, and a heat preservation reaction is conducted for 4-6 h; and S4, cooling the solution subjected to the heat preservation reaction in the step S3, and then washing and removing the solvent to prepare the low-dielectric and high-heat-resistance adamantane type maleimide resin. The adamantane type maleimide resin provided by the invention can solve the problems of poor solubility and high brittleness of maleimide resin, and meanwhile, the resin is endowed with excellent heat resistance. In addition, the adamantane type maleimide resin can also be used for preparing copper-clad plates with low dielectric constant and low dielectric loss.

The invention discloses a peracetylated polysaccharide derivative mixing accelerator as well as a preparation method and application thereof, and relates to the technical field of polysaccharide derivatives. Alkyl polyglucoside and glycidyl ether are subjected to etherification reaction to obtain polysaccharide derivatives; and adding acetic anhydride and an organic weak base catalyst into the polysaccharide derivative, and carrying out esterification reaction to obtain the peracetylated polysaccharide derivative. The obtained peracetylated polysaccharide derivative can be used for reducing the minimum miscible pressure of CO2 in an offshore oilfield. The polysaccharide derivative provided by the invention is simple in synthesis process, and the molecular activity of the polysaccharide derivative can be regulated and controlled by changing the number of carbon dioxide-philic groups and the length of oleophylic unsaturated hydrocarbon chains, so that the polysaccharide derivative can be used in the CO2 oil displacement process of oilfield exploitation, and the minimum miscible pressure in the CO2 oil displacement process is effectively reduced.

The present invention provides a chemical synthesis method of EPS-G7, wherein β-cyclodextrin A is acetylated to obtain β-acetylcyclodextrin B, B is ring-opened in a mixed solution of acetic anhydride / concentrated sulfuric acid to obtain a chain acetylated heptose C, p-nitrophenol is condensed with intermediate C using boron trifluoride acetonitrile to obtain a key intermediate p-nitrophenyl (G1)-O-acetyl-D-maltoseptaglycoside D with α as the dominant configuration, D is removed from the acetyl group under the action of sodium methoxide to obtain pNP-G7 (p-nitrophenyl (G1)-D-maltoseptaglycoside), pNP-G7 is in the presence of p-toluenesulfonic acid and dimethoxyethane, and acetal protection is formed between the hydroxyl groups on C4 and C6 of the terminal monosaccharide to obtain EPS-G7. The reaction raw materials used in the method of the present invention are cheap and readily available, and the chemical synthesis of α-amylase detection reagent EPS-G7 is realized, which is a simple, economical and efficient synthesis method.

The invention discloses a BTCP-Ac-Eu-MOF double-fluorescence-emission fluorescent probe as well as a preparation method and application thereof, and belongs to the technical field of detection probes. The preparation method comprises the following steps: synthesizing BTCP from salicylic acid and 2-aminothiophenol to obtain a product 1, and reacting the product 1 with acetic anhydride and triethylamine to obtain BTCP-Ac; the preparation method comprises the following steps: mixing europium nitrate hexahydrate and trimesic acid, and performing high-temperature reaction to obtain Eu-MOF powder; and the BTCP-Ac and the Eu-MOF are mixed, such that the BTCP-Ac / Eu-MOF dual-fluorescence emission fluorescent probe is obtained. The europium metal organic framework has a clear structure, ultrahigh porosity and a designable function, the europium metal organic framework is combined with AIE fluorescent molecules to enhance the performance of the europium metal organic framework, and the fluorescence of the europium metal organic framework can be used as a colorimetric reference, so that the function of sensitively, quickly and conveniently indicating the freshness of meat products is realized.

The invention discloses a synthetic method of a fluorescent dye, which comprises the following steps: A, dropwise adding POCl3 into DMF (Dimethyl Formamide) at the temperature of 0 DEG C under the condition of protective atmosphere and stirring, and fully reacting; continuously dropwise adding cyclohexanone, heating, stirring, fully reacting, adding the reaction liquid into ice water, and separating out a solid first compound; b, under the protective atmosphere, stirring and refluxing p-sulfonyl phenylhydrazine, 3-methyl-2-butanone and acetate in acetic acid to react completely, cooling the reaction liquid to-10 to 5 DEG C, stirring, and separating to obtain a second compound; c, under the protective atmosphere, after the second compound and 1, 4-butanesultone are stirred, refluxed and completely reacted in xylene, separating to obtain a third compound; and D, stirring and refluxing the third compound, the first compound and acetate in methanol at the temperature of 80 DEG C under the conditions of protective atmosphere and light shielding, simultaneously dropwise adding acetic anhydride, cooling to room temperature after full reaction, and separating and purifying. According to the scheme, the synthesis process is simple and efficient, and high-quality synthesis of the target dye S0456 is effectively realized.

The invention discloses multifunctional nano-enzyme composite hydrogel as well as a preparation method and application thereof. The preparation method comprises the following steps: synthesizing molybdenum disulfide MoS2 by taking hexaammonium heptamolybdate tetrahydrate and thiourea as raw materials; the preparation method comprises the following steps: carrying out stirring reaction on MoS2 and cysteine to obtain MoS2-LC; the preparation method comprises the following steps: mixing galangin with MoS2-LC, carrying out ultrasonic treatment, and carrying out a stirring reaction to obtain MoS2-LC (at) Gal; the preparation method comprises the following steps: adding acetic anhydride into a carboxymethyl chitosan aqueous solution to obtain N-acetylated carboxymethyl chitosan N-CC; the preparation method comprises the following steps: adding 1-butyl-3-methylimidazole chlorine salt into N-CC to react, and carrying out alcohol precipitation to obtain N-CC-IL; a cross-linking agent, MoS2-LC (at) Gal and N-CC-IL are subjected to a blending reaction, and SNCI (at) MLG is obtained. Pharmacodynamic results show that the multifunctional nano-enzyme composite hydrogel prepared by the preparation method disclosed by the invention can play a role in inhibiting ferroptosis while having an antibacterial effect, and a new possibility is provided for periodontal local treatment.

The invention discloses a preparation method of a six-membered azaspiro dihydrobenzofuran compound. According to the method, a C2-alkyne benzofuran derivative is taken as a raw material, metal palladium is taken as a catalyst, and a corresponding product is generated through reaction in an organic solvent at the temperature of 40-120 DEG C under the combined action of a ligand and acetic anhydride. Under the action of palladium, a ligand, a solvent and acetic anhydride, alkyne triple bonds and indole double bonds are subjected to triple addition and bicyclic addition, and rapid construction of a six-membered azaspiro structure dihydrobenzofuran product is achieved. The reaction conditions are mild, the operation is simple and convenient, and the method has the advantages of easily available reaction raw materials, wide substrate applicability, excellent yield and enantioselectivity, easily separated target products and the like.

The invention discloses a method for extracting light-color lignin based on a ternary complex solvent and application of the light-color lignin in sunscreen cream, and belongs to the field of lignin separation and high-value utilization thereof. The method comprises the following specific steps: mixing choline chloride, lactic acid and acetic anhydride to prepare a ternary composite solvent, heating plant fiber raw materials and the ternary composite solvent to react, and extracting the light-color lignin. According to the method disclosed by the invention, the molar ratio of choline chloride to lactic acid to acetic anhydride is 1: 1: (3-5), and the extracted lignin is faint yellow and shows a lighter color compared with other disclosed technologies. And after the prepared light-color lignin is mixed with the sunscreen cream according to the doping amount of 8wt%, the sunscreen index SPF reaches 38 and is close to the requirements of commercial sunscreen cream, and the light-color lignin does not generate a stain phenomenon on the skin when being smeared and used, has certain practical value and effectively expands the application potential of the lignin in the fields of cosmetics, ultraviolet absorbers and the like.

The invention discloses a solid waste-based multifunctional tailing asphalt pavement material and a preparation method thereof, and the pavement material comprises the following components in parts by mass: 4.5-5.5 parts of polyurethane modified asphalt, 45-60 parts of titanate modified iron tailings, 2-5 parts of surface activated copper tailing powder, 20-35 parts of copper tailing sand and 0.5-1.0 part of acetic anhydride modified wollastonite fiber. The high and low temperature performance, the durability and the self-healing performance of the asphalt mixture are comprehensively improved by modifying the solid waste tailing material and the asphalt, and the application range of the asphalt mixture is effectively widened.

The invention belongs to the technical field of energetic plasticizer preparation, and particularly discloses a method for preparing N-butyl nitroxyethyl nitramine through ionic liquid nitration. The method comprises the following steps: mixing an ionic liquid nitrating agent with butyl ethanolamine to obtain a mixed solution; and mixing the mixed solution with a catalyst and acetic anhydride, reacting, and carrying out post-treatment to obtain the N-butyl nitroxyethyl nitramine. According to the method, the ionic liquid with stable properties is adopted as the nitrating agent, the reaction is mild when the ionic liquid is mixed with the butylethanolamine, violent heat release caused when fuming nitric acid is in contact with the butylethanolamine is effectively avoided, and the ionic liquid precursor can be recycled through simple extraction after the reaction.

The invention provides a synthesis method for preparing high-yield tetraacetylethylenediamine at one time, which comprises the following steps: S1) taking ethylenediamine and toluene as a base, dropwise adding acetic acid, heating and refluxing at the same time, and dehydrating in a water segregator until no water is generated; s2) adding acetic anhydride and methylbenzene, carrying out low-temperature azeotropy to take out acetic acid, extracting and separating acetic acid from azeotropic liquid through ice water, drying a raffinate phase, then recycling the raffinate phase, carrying out high-temperature reflux reaction for 1 hour, and repeating low-temperature acid extraction and high-temperature reaction for three times respectively; the method has the advantages that the heat supply process and the methylbenzene low-temperature acid extraction process are repeatedly and sectionally implemented, so that the production efficiency is improved, the single yield is improved, the color of the product is better, and the method is suitable for large-scale industrial production.

The invention provides a method for detecting the hydroxyl value of a polyether material. The method comprises the following steps: (1) constructing a standard quantitative system of a derivatization reagent; (2) fully reacting a to-be-detected polyether material with the excessive derivatization reagent; (3) testing the peak area of the unreacted derivatization reagent by adopting chromatography; (4) comparing with a standard quantitative system of the derivatization reagent, and calculating the content of the unreacted derivatization reagent; and (5) calculating the consumption of the derivatization reagent in the step (2) by using the calculated content of the unreacted derivatization reagent, thereby calculating the hydroxyl value of the polyether material according to the stoichiometric relationship. Wherein the derivatization reagent comprises at least one hydroxyl esterifying agent selected from the following groups: phthalic anhydride, acetic anhydride and benzoyl chloride.

The invention discloses an environment-friendly p-hydroxyacetophenone production process, and particularly relates to the technical field of p-hydroxyacetophenone production, which comprises the following steps: step 1, respectively putting dissolved phenol and acetic anhydride into a synthesis reaction kettle, stirring and heating to 128 DEG C, refluxing for 5 hours at normal pressure, then carrying out heat preservation treatment, and reacting to generate phenyl acetate; 2, cooling phenyl acetate generated by the reaction to 60 DEG C, washing with water, standing for layering, and discharging phenyl acetate to generate a small amount of by-products containing 90% of glacial acetic acid; and 3, pumping the dehydrated phenyl acetate into a reaction kettle by a vacuum pump, gradually adding aluminum trichloride, then adding acidic water for hydrolysis, cooling to 60 DEG C, and discharging to obtain a liquid crude product of p-hydroxyacetophenone and o-hydroxyacetophenone. The environment-friendly performance of implementation is good, conditions needed by the technology are mild, the unstable condition is not prone to occurring in the operation process, and the practical application effect of the method is ideal.

The invention discloses a modified bamboo fiber reinforced polypropylene composite material and a preparation method thereof, and belongs to the field of polypropylene composite materials, the modified bamboo fiber reinforced polypropylene composite material is characterized by comprising the following raw materials by mass: 1-10 parts of modified bamboo fiber, 80-90 parts of polypropylene, and 1-5 parts of a compatilizer. The modified bamboo fiber is prepared by modifying the surface of bamboo fiber by using acetic anhydride as an acetylation reagent and concentrated sulfuric acid and glacial acetic acid as a solvent system. Through acetylation modification of the bamboo fiber, the surface hydrophobic effect of the bamboo fiber is greatly improved, the bamboo fiber adapts to a polypropylene polymer non-polar material, and the interfacial compatibility between the bamboo fiber and polypropylene is improved. Fine fibers can be separated from the modified bamboo fibers through two screw extrusion processes under the shearing action of the screws and are uniformly dispersed in a polypropylene matrix, the fine fibers have the effect of a heterogeneous nucleating agent on polypropylene, the reinforcing effect of the bamboo fibers on the polypropylene is improved, and the composite material is endowed with more excellent mechanical performance and thermal stability.

Disclosed in the present invention is a method for preparing cationic acetylated glutinous rice starch having high freeze-thaw stability. The method comprises: measuring glutinous rice starch and sodium chloride, then adding same to distilled water, transferring same into a closed container, adding 3-chloro-2-hydroxypropyltrimethylammonium chloride and an alkali reagent thereto, sealing the container, mixing same until uniform, then performing an etherification reaction at a set temperature, finally adjusting the pH, and performing centrifugal washing, drying and grinding, so as to obtain cationic glutinous rice starch; and then adding the cationic glutinous rice starch, an acetic anhydride reagent and an alkali reagent to a closed container at 26°C, adjusting the pH at the same time, stirring same for a certain period of time, then reacting same at 25-30°C for 60-65 min, and centrifugally washing, drying and crushing a product obtained from the reaction, so as to obtain cationic acetylated glutinous rice starch having high freeze-thaw stability. The properties of the product of the present invention, such as a water-swelling property, solubility, freeze-thaw stability and paste transparency, are all improved, especially, the freeze-thaw stability is improved; and improvements in these properties broaden the application range of the product in food products and other fields.

The invention relates to the technical field of organic polymer materials and the technical field of lithium batteries, in particular to polyimide and a preparation method and application thereof.The preparation method of the polyimide comprises the steps that in the inert gas atmosphere, a first solvent, a first monomer and a second monomer are subjected to a mixed reaction, pyridine and acetic anhydride are added, a reflux reaction is conducted, cooling is conducted, and the polyimide is obtained. And adding a second solvent, stirring, carrying out suction filtration, and drying. The polyimide is resistant to high temperature, the decomposition temperature is 500 DEG C or above, and the polyimide has good thermal performance, meanwhile, when the polyimide is applied to preparation of the lithium ion battery diaphragm in the form of nanofibers and nanoparticles, due to the fact that the polyimide has cohesiveness, the problem that the cohesiveness of a binder fails is solved, and due to the fact that the polyimide contains ether bonds and has higher affinity with electrolyte, the service life of the polyimide is prolonged. The wettability of the battery is improved; meanwhile, the polyimide is simple in preparation method, suitable for mass production and convenient for commercialized popularization.

The invention relates to the technical field of composite materials, and particularly discloses a polyimide-based composite material and a preparation method thereof. The polyimide-based composite material is prepared from the following raw materials in parts by weight: 5 to 30 parts of aromatic dianhydride monomer, 4 to 38 parts of aromatic diamine monomer, 1 to 10 parts of end-capping reagent, 5 to 30 parts of acetic anhydride, 3 to 15 parts of triethylamine and 35 to 60 parts of solvent. The preparation method comprises the following steps: carrying out low-temperature reaction on an aromatic diamine monomer and an aromatic dianhydride monomer in a solvent to form a polyamide acid solution, and carrying out chemical cyclization treatment to obtain fusible polyimide; the polyimide resin prepared by the invention is easy to melt and good in fluidity, solves the problems of higher melting point, difficulty in melting and poor fluidity of a polyimide-based composite material in the prior art, and reduces the forming difficulty of the composite material.