232 results about "Phosphorus pentoxide" patented technology

The invention discloses a hyperbranched water reducing agent for high-tensile wet joint UHPC (Ultra High Performance Concrete) as well as a preparation method and application of the hyperbranched water reducing agent, and belongs to the technical field of concrete admixtures. The preparation method comprises the following steps: mixing pentaerythritol and maleic anhydride, adding a catalyst p-toluenesulfonic acid, and carrying out an esterification reaction to prepare an esterification product; carrying out amidation reaction on the esterification product, diethanol amine and a catalyst sodium ethoxide to obtain a prepolymer; acrylic acid, maleic anhydride and the prepolymer are dissolved in deionized water, an initiator ammonium persulfate is added for a free radical copolymerization reaction, and a main chain polymer is obtained; carrying out phosphorylation reaction on the main chain polymer and phosphorus pentoxide to obtain a phosphorylated main chain polymer; the phosphorylated main chain polymer, methoxypolyethylene glycol and a catalyst p-toluenesulfonic acid are subjected to an etherification reaction, a hyperbranched comb-shaped polymer water reducing agent solution is obtained and then subjected to aftertreatment, and the water reducing agent is prepared. According to the hyperbranched comb-shaped polymer water reducing agent prepared by the preparation method disclosed by the invention, the problems of poor flowability and high viscosity of ultra-high performance concrete (UHPC) are solved by combining a linear side chain of a comb-shaped structure and a three-dimensional branch of hyperbranched topology.

The invention discloses a comb-type polyphosphate polymeric dispersant and a preparation method thereof, the dispersant is prepared by preparing a phosphate monomer from acrylate and phosphorus pentoxide, then copolymerizing the phosphate monomer with phenyl alkene or alkyl alkene, and finally adding alkali liquor for neutralization. A phosphate-polyether bifunctional side chain is introduced to a main chain, a phosphate group provides electrostatic repulsion, and a polyether group enhances steric hindrance, so that the dispersing agent can meet the requirements of strong adsorption and long-range stability at the same time, and a more durable and effective stabilizing effect is provided for a dispersion system.

The invention provides a thermal response self-ceramization fireproof coating and a preparation method thereof. The thermal response self-ceramization fireproof coating is prepared from the following raw materials in parts by mass: 3 to 10 parts of acrylic monomer, 3 to 10 parts of organic sulfonate, 1 to 4 parts of silane coupling agent, 0.5 to 3 parts of silicate ester, 4 to 6 parts of ceramic precursor, 3 to 6 parts of fluxing agent and 0.05 to 0.4 part of initiator. The fluxing agent comprises a component A and a component B, the component A is one of boric oxide, zinc borate or low-melting-point glass powder, and the component B is one of phosphorus pentoxide and ammonium polyphosphate. The silane coupling agent can be copolymerized with an acrylic monomer to construct a C-C main chain, the C-C main chain and silicate ester are subjected to hydrolytic condensation to form a Si-O-Si three-dimensional network, a chemical cross-linked skeleton is formed, and the chemical cross-linked skeleton can generate silicon dioxide at high temperature to participate in a ceramization reaction; the ceramic precursor and silicate ester can form a strong physical cross-linking effect, so that the fireproof coating with a chemical and physical double-cross-linked network can be formed, and the fireproof coating has excellent mechanical property and machinability at normal temperature.

The invention discloses an ardealite-based slow release fertilizer and a preparation method thereof, the ardealite-based slow release fertilizer comprises: a core layer, the core layer comprises ardealite and a complex microbial inoculant; in the phosphogypsum, the content of fluoride is less than or equal to 0.1 wt%, and the content of phosphorus pentoxide is more than or equal to 0.1 wt%; the complex microbial inoculants comprise phosphorophilic bacteria; and the material of the coating layer comprises a scene response material. Therefore, according to the ardealite-based slow release fertilizer, the utilization rate of ardealite can be effectively increased, and meanwhile, the slow release performance of the slow release fertilizer is further optimized.

The invention relates to a process for preparing a phosphor copper rod by using a phosphonate-amide composite purifying agent as a quenching aid, and belongs to the technical field of non-ferrous metallurgy. Phosphorus pentoxide and sodium carbonate are mixed and decocted into fused salt, the fused salt is cooled and ground and then added into a corundum crucible together with scrap copper to be rapidly heated, compressed air is blown in, and slagging-off is conducted after heat preservation and standing; blowing mixed gas into the melt for reduction refining; adding calcium boride into the melt for refining; the refined copper liquid is subjected to continuous casting and continuous rolling; rapidly immersing the phosphorus copper rod subjected to continuous casting and rolling into a quenching aid solution, and carrying out quenching treatment; and the quenched phosphor copper rod is blow-dried and dried, and the high-conductivity phosphor copper rod is obtained. The high-purity phosphorus copper rod prepared by the method is excellent in key indexes of copper content, phosphorus content and conductivity, and meets the expected requirements of high purity and high conductivity.

The invention discloses a toughened glass ceramic and a preparation method thereof, and relates to the technical field of glass ceramics, and the toughened glass ceramic comprises the following components in percentage by weight: 64 to 68 weight percent of silicon dioxide, 22.67 to 26.5 weight percent of lithium oxide, 0.9 to 1.2 weight percent of antibacterial agent, 0.8 to 1.1 weight percent of modified mica powder, 1.98 to 2 weight percent of aluminum oxide, 1.78 to 1.8 weight percent of potassium oxide, 1.68 to 1.7 weight percent of zirconium dioxide, 1.19 to 1.2 weight percent of phosphorus pentoxide and 1 to 3 weight percent of calcium fluoride. According to the toughened glass ceramic and the preparation method thereof, a multi-scale anti-cracking network is formed through macroscopic crack deflection of mica and nanoscale phase change toughening of zirconium oxide, the fracture toughness is remarkably improved, zirconium oxide agglomeration can be reduced through interface optimization of modified mica powder, zirconium oxide is dispersed more uniformly, and the phase change potential is further exerted; due to high-temperature stability of aluminum oxide, antibacterial agent particles can be wrapped, and excessive volatilization or aggregation of the antibacterial agent particles in the sintering process is prevented; aluminum oxide is used as a'protective shell 'to delay the Cu < 2 + > release rate and realize long-acting antibiosis.

The invention relates to the technical field of modified carbon graphite materials, and particularly discloses an antioxidant modified carbon graphite material and a preparation method thereof, the antioxidant modified carbon graphite material comprises the following raw materials by weight: 30-34 parts of medium temperature pitch, 4-6 parts of modified silica sol and 10-12 parts of artificial graphite powder; from two aspects, firstly, the aluminum dihydrogen phosphate and the boric acid aqueous solution are added, the aluminum dihydrogen phosphate can promote the asphalt to form a denser and firmer glassy carbon structure during carbonization, and phosphorus pentoxide generated by decomposition of the aluminum dihydrogen phosphate and boron oxide generated by dehydration of boric acid can generate a glass phase with an anti-oxidation effect; secondly, core-shell particles are added, a shell layer of the core-shell structure is an aluminum hydroxide structure generated by hydrolyzing aluminum nitrate nonahydrate, and an inner core is epoxidized nano silicon carbide; through the synergistic effect of the two, the mechanical property and the oxidation resistance of the carbon-graphite material are improved.

The invention discloses bacteriostatic and antibacterial lithium disilicate glass ceramic and a preparation method thereof. The bacteriostatic and antibacterial lithium disilicate glass ceramic comprises the following components in percentage by weight: 60-70% of lithium disilicate whiskers, 5-12% of a nucleating agent, 1-5% of aluminum oxide, 1-4% of calcium oxide, 5-10% of an antibacterial agent and 12-18% of fluorapatite, wherein the nucleating agent is formed by compounding phosphorus pentoxide and zirconium oxide, and the antibacterial agent is formed by compounding silver oxide and zinc oxide; the invention relates to the technical field of lithium disilicate glass ceramics. In the glass ceramic, silver ions can be combined with groups such as sulfydryl and amino in bacterial cells to interfere the metabolic process of bacteria and inactivate enzymes of the bacteria so as to inhibit growth and reproduction of the bacteria, and zinc ions can influence permeability of bacterial cell membranes and destroy physiological functions of the bacteria and cooperate with the silver ions to enhance the antibacterial effect of the glass ceramic.

The application provides a sulfide solid electrolyte and a preparation method thereof, and particularly relates to the technical field of secondary batteries. The sulfide solid electrolyte is a lithium phosphorus oxysulfide, and the chemical formula of the lithium phosphorus oxysulfide is Li7P3S 7.5+x‑5y O 3.5‑x+5y ; wherein, 0<=x<=3.5, 0<=y<=1.5, -7.5

The invention discloses a high-strength acrylate rubber material and a preparation method thereof, and relates to the technical field of high polymer materials. When the high-strength acrylate rubber material is prepared, polyhydroxy imidazolium salt and phosphorus pentoxide react to prepare a functional flame retardant; reacting the pre-modified glass fiber with hydrazine hydrate to obtain modified glass fiber; the preparation method comprises the following steps: carrying out solution polymerization on ethyl acrylate, butyl acrylate, acryloxy propyl bis (trimethylsiloxy) methylsilane and glycidyl methacrylate to prepare acrylate raw rubber; the high-strength acrylate rubber material is prepared by uniformly mixing acrylate raw rubber, the modified glass fiber, a functional flame retardant and triphenyl phosphine, plastifying and thin-passing. The high-strength acrylate rubber material prepared by the invention has excellent flame-retardant, antibacterial, anti-aging and mechanical properties.

The invention provides a synthesis method of an OLED polycyclic fused thiophene compound, and relates to the technical field of material synthesis, and the synthesis method comprises the following steps: providing and mixing 2-naphthalene sulfonic acid and dichloromethane, dropwise adding an N-bromosuccinimide solution into the mixture under the protection of inert gas, and reacting to obtain an intermediate A; dissolving the intermediate A, then adding sodium hydroxide, 4-bromophenylboronic acid, water and tetrakis (triphenylphosphine) palladium, and reacting to obtain an intermediate B; dissolving the intermediate B, adding sulfonic acid and phosphorus pentoxide, and reacting to obtain an intermediate C; adding the intermediate C into tetrahydrofuran, dissolving, adding lithium aluminum hydride under inert gas, and reacting to obtain a target compound. According to the method, the chemical reaction efficiency of the intermediate C is high, and the yield and LC purity of a target product are relatively high.

The invention discloses an anti-ultraviolet solar cell backboard film and a preparation method thereof, and relates to the technical field of solar cell backboards, the anti-ultraviolet solar cell backboard film comprises a first anti-ultraviolet functional layer, a polyester base layer and a second anti-ultraviolet functional layer from top to bottom in sequence; the first uvioresistant functional layer and the second uvioresistant functional layer are independently prepared from the following raw materials: a functional polymer, 2-acrylamido-2-methylpropanesulfonic acid, 1, 3-bis (oxiranyl methyl)-5-(2-propenyl)-1, 3, 5-triazine-2, 4, 6 (1H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H The invention relates to a high-temperature-resistant nano-emulsion which is prepared from N-(4-cyano-3-trifluoromethylphenyl) methacrylamide, N-(4-cyano-3-trifluoromethylphenyl) methacrylamide, a nano-assistant, a coupling agent, an initiator, polyphosphoric acid and phosphorus pentoxide. The backboard film is good in ultraviolet aging resistance, good in interlayer peel strength and excellent in barrier property.

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a method for synthesizing lithium hexafluorophosphate from lithium tripolyphosphate. The synthesis method comprises the following steps: uniformly mixing lithium tripolyphosphate and phosphorus pentoxide in an ether solvent to obtain a first mixture; introducing a mixed gas of hydrogen fluoride and nitrogen into the first mixture, and carrying out a mixed reaction to obtain a second mixture; and carrying out solid-liquid separation on the second mixture, and carrying out reduced-pressure concentration, recrystallization and reduced-pressure drying on the filtrate after solid-liquid separation to obtain lithium hexafluorophosphate. The lithium tripolyphosphate, the phosphorus pentoxide and the hydrogen fluoride are used as raw materials, the hydrogen fluoride gas is uniformly introduced for reaction, the lithium hexafluorophosphate is directly synthesized in the ether solvent, and the method has the advantages of mild reaction conditions, high reaction efficiency, high product purity and high yield. The problems of more byproducts, high cost and the like in the industrial production process of lithium hexafluorophosphate are solved.

The invention discloses a phosphorite ore blending optimization method based on a multi-modal large model and intelligent interaction hardware. The phosphorite ore blending optimization method comprises the following specific steps: 1) collecting related parameters; 2) dynamically optimizing and inputting the multi-modal large model; and 3) dynamically optimizing and outputting the multi-modal large model. The invention relates to the field of methods, in particular to a phosphorite ore blending optimization method based on a multi-modal large model and intelligent interaction hardware, and particularly relates to a phosphorite ore blending optimization system and method based on the multi-modal large model. Through fusion of deep learning, conditional constraint planning and intelligent interaction hardware, multi-target dynamic optimization of phosphate ore blending is realized, and the method is suitable for low-cost ore blending scheme generation under multi-index constraints of phosphorus pentoxide (PO), magnesium oxide (MgO), arsenic (As) and calcium oxide (CaO).

This invention belongs to the field of high-performance materials and discloses a method for preparing a controllable PBO polymer. The steps are as follows: phosphorus pentoxide is dissolved in polyphosphoric acid to obtain high-concentration polyphosphoric acid; in reactor A, DAR and small-particle-size TPA are subjected to initial prepolymerization in the high-concentration polyphosphoric acid; the above materials are transported to reactor B, and large-particle-size TPA is added for secondary prepolymerization; final polymerization is carried out in a twin-screw extruder, and by adding an appropriate amount of DAR, a PBO polymer with controllable degree of polymerization is obtained; the PBO polymer is precipitated in water and dried to obtain the PBO polymer. This method first adds phosphorus pentoxide to polyphosphoric acid to prepare high-concentration polyphosphoric acid, avoiding the problems of poor powder dispersion, exothermic dissolution, and excessively high temperature that occur when adding phosphorus pentoxide during the polymerization reaction. Furthermore, by adding DAR monomer in the extruder to control the degree of polymerization of PBO macromolecules, the degree of polymerization is controllable, which has high practical value.

The application discloses a method for preparing high-temperature-resistant and anti-degradation well cementing material by using high-aluminum and high-silicon solid wastes, and the content of each component in the raw material is calculated according to the total mass of 100%, and the content of glass is 32-48%, the content of waste ceramic is 30-45%, the content of aluminum oxide is 15-25%, the content of boron trioxide is 1.1-4.8%, the content of alkaline earth metal oxide is 1.6-4.6%, the content of alkali metal oxide is 0.7-4.6%, the content of zirconium oxide is 0.8-5%, the content of zinc oxide is 0.4-2%, and the content of phosphorus pentoxide is 0.4-2%. The raw material is crushed, ground and grinded, the high-silicon aluminum precursor particles prepared by physical methods, chemical methods or the combination of both are pretreated, high-temperature spheroidized and surface-coated, so that the high-temperature-resistant and anti-degradation spherical additive product is prepared. The product has the excellent performances of high sphericity, good fluidity, small friction resistance, easy mixing, simple use and the like; the high-temperature resistance and anti-degradation are obvious under the well condition that the bottom hole static temperature is 150-300 DEG C, and the cement stone strength is obviously improved.

Dichloroacetonitrile is an important raw material required for the production of florfenicol, a new Class II veterinary drug in China, and has a promising market prospect. The present invention discloses a method for preparing dichloroacetonitrile, comprising the following steps: using dichloroacetaldehyde as a raw material, in the presence of different nitrogen sources and a copper catalyst, and using air as an oxidant to generate dichloroacetonitrile. The reaction liquid is filtered, extracted, and distilled to obtain a colorless liquid with a purity greater than 99%. Compared with the traditional method of preparing dichloroacetonitrile using phosphorus pentoxide, the present invention has a simple reaction, mild conditions, simple post-processing, and is more environmentally friendly, providing a new approach to the production of dichloroacetonitrile.

The invention relates to the technical field of chemical preparation, and discloses a preparation method of a phthalimide compound, which comprises the following steps: S1, raw material mixing: sequentially adding phthalic anhydride, a primary amine compound, p-toluenesulfonic acid and phosphorus pentoxide into a reaction container with a stirring device and a temperature control module, and stirring for 1-2 hours; adding ethanol as a solvent, and carrying out a stirring reaction; s2, curing: cooling the reaction liquid to 20-25 DEG C, slowly adding deionized water into the reaction liquid while stirring, standing, and separating out a solid product; a traditional dehydrating agent is changed into a low-cost green dehydrating agent combination, so that the cost loss is reduced, the stimulation effect is reduced, the catalytic activity is equivalent to that of p-toluenesulfonic acid by adding a new sulfonic group functional polymer, but the problems of volatility of liquid acid and equipment corrosion are avoided, a low-toxicity and low-cost solvent of ethanol is added, the toxicity is reduced, and the environment-friendly dehydrating agent is prepared. The preparation is safer, the cost is lower, and the applicability is wider.

The present disclosure relates to a method for preparing hexamethylenediamine from caprolactam, comprising the following steps: contacting caprolactam and ammonia with a first catalyst under catalytic amination reaction conditions to carry out an amination-dehydration reaction to obtain a first product containing 6-aminocapronitrile; and contacting the first product with hydrogen and a second catalyst under catalytic hydrogenation reaction conditions to carry out a hydrogenation reaction to obtain a second product containing hexamethylenediamine; the first catalyst comprising, on a dry basis and based on the total weight of the first catalyst, 5-95 weight percent of a titanium-containing support, 2-30 weight percent of a vanadium oxide, 0.5-10 weight percent of phosphorus pentoxide, 1-20 weight percent of a metal M oxide, and / or 0-5 weight percent of an inorganic oxide; the titanium-containing support comprises TiO2 and a titanium-containing molecular sieve, and the inorganic oxide comprises one or both of Al2O3 and SiO2.

This invention discloses a bioactive glass and its preparation method, belonging to the field of bioactive glass technology. It aims to solve the problems of insufficient synergistic effect between antibacterial efficacy and bone-promoting activity in existing materials, as well as the inability to monitor in vivo degradation processes in real time. The bioactive glass comprises 44-48 parts silica; 22-27 parts calcium oxide; 22-27 parts sodium oxide; 5-7 parts phosphorus pentoxide; 2-4 parts europium zinc complex; 10-20 parts chitosan; 1-5 parts lidocaine; and 2-5 parts dilute acetic acid solution. The addition of the europium zinc complex promotes bone formation and enhances antibacterial activity, achieving a highly efficient synergy between anti-infection and tissue regeneration. Simultaneously, it provides optical tracking capabilities, allowing for non-destructive real-time monitoring of the material's degradation behavior and tissue integration in vivo via fluorescence imaging. This invention offers superior material performance and a simple preparation process, providing an innovative solution for the repair of infected bone defects.

The invention discloses a method for determining the total phosphorus content in ammonium polyphosphate, and relates to the technical field of chemical analysis and detection. The method comprises the following steps: weighing an ammonium polyphosphate sample, putting the ammonium polyphosphate sample into a microwave digestion tube, adding a nitric acid solution, covering and sealing, putting the microwave digestion tube into a microwave digestion instrument for digestion, transferring a digestion solution into a volumetric flask for constant volume, uniformly mixing and filtering, and taking a filtrate as a to-be-tested solution; preparing a phosphorus pentoxide standard series solution; placing the standard series solution and the to-be-tested solution in a sample disc of a continuous flow injection analysis automatic sampler in sequence, setting parameters, operating the equipment for detection, fitting a standard curve according to peak height, calculating the mass concentration of phosphorus pentoxide in the to-be-tested solution, and further calculating the total phosphorus content in the sample. According to the method, microwave closed digestion is utilized, the reaction speed and intensity are higher in the process, the medium-high ammonium polyphosphate digestion is more thorough, a continuous flow injection analyzer is used for automatic sample introduction and determination, manual operation errors are reduced to the maximum extent, the detection flux is high, the speed is high, and consumed time is less.

The application relates to the technical field of fine chemicals, in particular to a biomimetic amphoteric surfactant as well as a preparation method and application thereof; the preparation method of the biomimetic amphoteric surfactant comprises the following steps: reacting a fatty amine polyoxyethylene ether with a halogenated hydrocarbon to obtain a benzyl quaternary ammonium salt intermediate; cooling the benzyl quaternary ammonium salt intermediate, then adding phosphorus pentoxide to react; after the addition is completed, water is added, the reaction is continuously carried out, and the biomimetic amphoteric surfactant is obtained; the biomimetic amphoteric surfactant simultaneously integrates three characteristics of phosphate anion, polyether non-ion and benzyl quaternary ammonium salt cation, effectively solves the industry problem that traditional phosphates and cationic settling agents are incompatible, and is applied to metal processing fluid, can realize stable compounding with cationic settling agents while retaining excellent extreme pressure lubricity and hard water resistance, and can replace traditional extreme pressure agents such as environmentally-unfriendly chlorinated paraffin.

The application discloses a preparation method and system of sodium difluorophosphate. The preparation method of sodium difluorophosphate comprises the following steps: S100, in a water-free or low-water environment, a solid-phase reaction is generated between diphosphorus pentoxide and ammonium fluoride to obtain an ammonium difluorophosphate intermediate, and volatile substances generated in the reaction process are removed and recovered; S200, in a water-free organic solvent, the ammonium difluorophosphate intermediate obtained in the step S100 is reacted with a sodium salt to obtain sodium difluorophosphate. The preparation method of sodium difluorophosphate provided by the application uses diphosphorus pentoxide and ammonium fluoride as reaction raw materials to obtain an ammonium difluorophosphate intermediate, and then reacts to obtain sodium difluorophosphate. The obtained sodium difluorophosphate has high purity and few impurities. The preparation method of sodium difluorophosphate has the advantages of cheap and easily obtained raw materials, stable chemical properties, few by-products generated in the reaction, and easy recovery, and is a green and safe preparation method of sodium difluorophosphate.

The application discloses a production process of electroplating grade potassium pyrophosphate, which uses potassium carbonate and diaphosphorus pentoxide as raw materials, and adds a catalyst to react in a high-pressure reaction kettle. After the reaction is completed, water is added for dissolution, and the pH value of the slurry is controlled to be 9.0-10.0. After being filtered through a precision filter, the slurry is punched into a slurry storage tank, and the slurry storage tank is maintained at 75-95 DEG C. The slurry in the storage tank is punched into an evaporation and concentration device for concentration, and then the concentrated liquid is punched into a continuous crystallization device for continuous crystallization operation. After centrifugal treatment, the filtrate is recycled into the evaporation and concentration device. The potassium pyrophosphate crystals are subjected to vacuum drying treatment in a vacuum drying equipment, and then are packaged into finished products after being crushed and sieved. The potassium pyrophosphate crystals obtained by the application have high purity, less caking phenomenon, and stable and controllable product quality.

The invention discloses a collophanite dry sorting method based on combination of color sorting and a dense medium fluidized bed. According to the method, aiming at the defects of high environmental protection risk and insufficient single color sorting precision of existing wet sorting, efficient quality improvement of medium-low-grade collophanite is realized through a synergistic process of color sorting classification and dry-method dense medium fluidized bed enrichment: firstly, raw ore is crushed, concentrate, middling and tailings are obtained through two-stage color sorting classification, the concentrate is subjected to secondary color sorting, and the concentrate is subjected to secondary color sorting; the crushing size fraction is adjusted according to the content of phosphorus pentoxide, then an iron powder dense medium matched with the mineral particle size is adopted, and accurate separation is achieved through differentiated fluidization separation density. The whole process is free of water and chemical agents, the average grade of the concentrate reaches 20% or above, the phosphorus recovery rate is 80% or above, the environment-friendly requirements of ecological sensitive areas such as water sources are met, medium-low-grade resources can be fully utilized, the production cost is reduced, and the adaptability is wide.

A sustainable control release fertilizer and a producing method thereof are developed. The sustainable control release fertilizer comprises a natural char / struvite composite with different ratio of the natural char to struvite (0:100, 25:75, 50:50, 75:25). The natural char / struvite composites represent a phosphorus pentoxid content in a range of 16 wt% to 25 wt% which is more than a common phosphate fertilizer. Furthermore, a mole ratio of Mg2+:NH4+:PO4 3- in the sustainable control release fertilizer is 2:1:1. The sustainable control release fertilizer can enhance phosphorus uptake of at least one plant at early stage of growth due to its composition as well as the developed producing method of sustainable control release fertilizer is based on recovery of phosphorus from wastewater that has the good economic and environmental effects.

The invention relates to the technical field of glass ceramics, and discloses a dental glass ceramic and a preparation method thereof. The invention discloses a high-temperature-resistant ceramic which comprises the following components in percentage by mole: 40-60% of silicon dioxide, 10-25% of sodium oxide, 0-5% of potassium oxide, 10-25% of aluminum oxide, 1-8% of diboron trioxide, 2-13% of 3YSZ, 1-5% of lithium oxide, 1-5% of calcium oxide, 0.3-2% of titanium dioxide, 0-4% of phosphorus pentoxide, 0-0.2% of lanthanum oxide, 0.1-1% of a clarifying agent, 0-1% of a coloring agent and 0.05-0.5% of F <->, wherein Al2O3 / Na2O + K2O is more than 0.7 and less than 1.1; 3 YSZ + P2O3 + TiO2 is more than 2% and less than 16%; the ratio of B2O3 to Al2O3 is greater than 0.2; the 3YSZ is tetragonal phase ZrO2 containing 3% of a Y2O3 stabilizer. The dental glass ceramic has good mechanical properties and a lower coefficient of thermal expansion, and can effectively improve the problems of interface stress concentration caused by a high coefficient of thermal expansion of the existing dental repair material and irregular shrinkage deformation adaptation of a dental crown material and the like.

The invention relates to the technical field of preparation of fluorine-containing intermediates, and discloses a synthesis method for preparing 4, 4 '-difluorobenzophenone through a one-pot domino reaction. The invention aims to solve the problems of expensive raw materials, complex process, serious pollution, low yield and purity and the like in the prior art. According to the method, 4-fluorobenzoic acid and fluorobenzene are taken as raw materials, any one or more of trifluoromethanesulfonic anhydride, phosphorus pentoxide, trifluoroacetic anhydride or paraformaldehyde is taken as an acid catalyst under a solvent-free condition, and a target product is directly prepared through a one-pot reaction. After the reaction is finished, excessive fluorobenzene is recovered, a high-purity product is obtained through extraction, alkali washing, drying and concentration, and unreacted 4-fluorobenzoic acid can be recovered by acidifying a water phase. The method has the advantages of simple process, easily available raw materials, mild conditions and environmental protection, realizes the excellent effects that the conversion rate of 4-fluorobenzoic acid is greater than 99%, the product yield is greater than 95% and the purity is greater than 99%, and is suitable for industrial production.

The invention discloses a preparation method of phosphorus pentafluoride, which comprises the following steps: 1) mixing fluorine-containing inorganic salt and hydrogen-containing inorganic salt, and carrying out activation process treatment; and 2) adding phosphorus pentoxide into the system in the step 1) for reaction to generate phosphorus pentafluoride gas. The method has the advantages of low reaction temperature and high product purity, does not need to use high-toxicity and high-corrosivity hydrogen fluoride, and is environment-friendly, simple in process and suitable for industrial production.