86 results about "P-hydroxybenzoic acid" patented technology

The invention discloses a method for preparing high molecular weight thermotropic liquid crystal polyester through melt coupling solid phase polycondensation. The method comprises the following steps: mixing p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and a catalyst 1-methylimidazole according to a specific molar ratio of (70-75): (25-30) to synthesize a liquid crystal polyester prepolymer with specific logarithmic viscosity; the preparation method comprises the following steps: crushing and drying a liquid crystal polyester prepolymer, placing prepolymer particles in a solid phase polycondensation device, accurately controlling the time and temperature of the polycondensation reaction, carrying out heating reaction in a nitrogen atmosphere to obtain high molecular weight thermotropic liquid crystal polyester, taking out the high molecular weight liquid crystal polyester, and carrying out viscosity test. In the preparation process of the prepolymer, the prepolymer with proper logarithmic viscosity can be effectively prepared by controlling the reaction temperature and time, so that the controllable preparation of the polymer is realized; the solid-phase polycondensation time required for obtaining the high-molecular-weight polymer is shortened by crushing the prepolymer into particles with different diameters, so that the solid-phase polycondensation efficiency is improved.

The invention discloses a smoke-suppression flame-retardant ecological board and a preparation method thereof. The ecological board comprises a base material, a flame-retardant adhesive layer and a facing layer which are sequentially stacked, wherein the flame-retardant adhesive layer is prepared from the following raw materials: 100 parts of urea-formaldehyde resin, 10-15 parts of a phosphorus-nitrogen composite flame retardant and 5-10 parts of flame-retardant filler; the preparation method of the phosphorus-nitrogen composite flame retardant comprises the following steps: carrying out an aminomethylation reaction on p-hydroxybenzoic acid, ethanolamine and paraformaldehyde which are used as raw materials in a molar ratio of 1: (1-1.2): (2-2.2) to prepare a Mannich base intermediate; and carrying out substitution reaction on the Mannich base intermediate and phosphonitrilic chloride trimer serving as raw materials according to the molar ratio of (3-7): 1. The phosphorus-nitrogen flame retardant disclosed by the invention is high in content of phosphorus and nitrogen elements and uniform in distribution ratio, and has more excellent synergistic smoke suppression and flame retardant effects compared with an existing physical compound system.

The invention provides high-strength and high-toughness PET (Polyethylene Terephthalate) foam as well as a raw material composition and a preparation method thereof. The raw material composition comprises: 100 parts of PET resin; 0.3 to 0.75 part of a dispersion phase; 10 parts or less of naphthyl hydroxyformic acid-p-hydroxybenzoic acid copolyester; and 10 parts or less of a thermoplastic elastomer. The invention further provides high-strength and high-toughness PET foam prepared from the raw material composition and a preparation method of the high-strength and high-toughness PET foam. The PET foam prepared by the invention has good mechanical properties, and especially has relatively high compression strength, shear strength and shear elongation at break.

The invention discloses a polyurethane bonding layer resin material, which belongs to the field of high polymer material and structure bonding, and comprises 40-60 parts by mass of a prepolymer A which is obtained by reacting 4, 4 '-diphenylmethane diisocyanate with polyether polyol with the molecular weight of 1800-2200g / mol and the hydroxyl value of 55-65mgKOH / g in the absence of a metal catalyst, and the mass fraction of residual NCO is 3-7%; the hydroxyl-terminated chain extender B is a blend of 1, 4-butanediol and 1, 6-hexanediol, and the molar ratio of the 1, 4-butanediol to the 1, 6-hexanediol is (1.0: 1)-(2.0: 1); the aromatic block modifier C is formed by condensation polymerization of p-hydroxybenzoic acid and isophorone diisocyanate, and the content of aromatic rings in the aromatic block modifier C is 30%-50%; 3 to 8 parts of a fluorine-containing isocyanate modifier D; 1 to 5 parts of an anti-migration stable component E; and 2-6 parts of a crosslinking density regulator F. The adhesive provided by the invention has excellent damp-heat aging resistance, dimensional stability and solvent resistance, high bonding strength and stable interface bonding, and is suitable for long-term bonding application in a complex environment.

The invention relates to polyarylester containing a furandicarboxylic acid unit and a preparation method thereof, and the polyarylester is prepared by the following steps: carrying out melt polycondensation on several monomers such as p-hydroxybenzoic acid, biphenol, terephthalic acid, 2, 5-furandicarboxylic acid and acetaminophen to prepare a prepolymer; and carrying out solid-phase polycondensation reaction on the prepolymer in a rotary kiln under a nitrogen protection condition. The furan-dicarboxylic acid is used as a bio-based product, is a green and renewable substitute of terephthalic acid / isophthalic acid, and meets the green and environment-friendly requirements in the future. The polyarylester obtained by the method can be subjected to melt processing at the temperature of 330-390 DEG C, and is engineering plastic with excellent mechanical properties.

The invention discloses an extraction method of microalgae, and belongs to the technical field of microorganisms, and the extraction method comprises the three steps of microalgae culture, enzymolysis reaction and compounding aftertreatment. When a microalgae extract is applied to a microalgae fertilizer, the yield and quality of crops can be effectively improved; and the schizochytrium limacinum culture medium is treated by using p-hydroxybenzoic acid and diammonium phosphate, so that the cell membrane permeability of the schizochytrium limacinum is changed, other nutrient substances can enter the schizochytrium limacinum conveniently, and meanwhile, cell wall breaking of the schizochytrium limacinum is facilitated. Under a proper ratio of an enzymolysis mixture, pyrolytic biochar, bentonite and biomass tar, the prepared microalgae-biochar simultaneously has abundant pore structures, a large amount of microalgae loads and strong combination structural performance, the activity performance of the microalgae-biochar can be effectively maintained, and the application range of the microalgae-biochar is widened. The method has a wide market prospect when being used for preparing a microalgae fertilizer.

The present application relates to the field of textiles, and specifically discloses a kind of different shrinkage polyester low-elastic yarn and its preparation process, and its preparation process comprises the following steps: using aliphatic diol and aromatic acid as raw materials to carry out esterification reaction to obtain polyester raw materials; modifying the polyester raw materials with a regulator containing at least magnesium hydroxide whiskers and p-hydroxybenzoic acid to obtain primary modified polyester; mixing the primary modified polyester with apocynum fiber powder, modified organic bentonite and a compatibility promoter to carry out modification to obtain melt granulation to obtain modified polyester masterbatch; spraying the obtained modified polyester masterbatch and polyester chips from a convex-shaped spinneret hole, passing through an ultra-short windless zone under a spray washing plate, and then cooling and solidifying in a gradient-distributed uneven manner, and then undergoing low-temperature elasticization treatment to obtain different shrinkage polyester low-elastic yarn; the present application also discloses the different shrinkage polyester low-elastic yarn obtained by the above process, and the present application has the characteristics of having a far-infrared emission function on the basis of obtaining a single-component different shrinkage polyester low-elastic yarn.

The invention relates to the technical field of biology, in particular to a recombinant strain for synthesizing vanillin and application of the recombinant strain. According to the invention, a vanillin non-degradable yeast strain is taken as a chassis, a new way for efficiently synthesizing vanillin by taking glucose as a precursor is designed and constructed, chorismic acid is taken as a key intermediate, chorismic acid lyase UbiC is introduced to convert the chorismic acid into p-hydroxybenzoic acid, and then vanillin is gradually synthesized through carboxylic acid reduction, hydroxylation and methylation; and more efficient de novo synthesis of vanillin and glucose vanillin is realized subsequently through strategies such as optimization of integration sites and removal of glycosylation in-situ products. The constructed engineering strain has the capacity of efficiently converting glucose to synthesize vanillin, the highest value reported at present can be obtained through fermentation in a shake flask, higher yield is obtained through further optimization of a bioreactor, and important reference value is provided for subsequent production and application.

The present invention discloses a fermentation method for Antrodia camphorata mycelium and an auxiliary composition for fermentation of Antrodia camphorata. The method provided by the present invention comprises the following steps: S1. subjecting an Antrodia camphorata strain to liquid fermentation for 60-120 hours; S2. adding precursors to the fermented Antrodia camphorata strain liquid fermentation broth, and continuing the fermentation for more than 120 hours to obtain Antrodia camphorata mycelium; the precursors being coenzyme Q0, p-hydroxybenzoic acid, linalool, and α-terpineol, and the fermentation broth after adding the precursors having a coenzyme Q0 content of 100-500 mg / L, a p-hydroxybenzoic acid content of 20-300 mg / L, a linalool content of 0.1-0.5 mg / L, and an α-terpineol content of 0.3-0.7 mg / L. This method adds precursor substances of specific composition and concentration to the liquid fermentation broth of Antrodia cinnamomea at a certain time and combines them with each other, which is beneficial to the secondary metabolism of Antrodia cinnamomea and promotes the synthesis of triterpenoid compounds, thereby increasing the yield. Compared with the existing technology, the yield of triterpenoid compounds produced by Antrodia cinnamomea mycelium is increased, the culture cycle is shortened, and it is more suitable for large-scale production.

The invention provides a corrosion-resistant film, a pipe and a preparation method and application of the corrosion-resistant film, the corrosion-resistant film at least contains modified LCP, the modified LCP comprises p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and 3, 4-dihydroxythiophene methyl diformate, the p-hydroxybenzoic acid, the 6-hydroxy-2-naphthoic acid and the 3, 4-dihydroxythiophene methyl diformate are used as raw materials, and the 6-hydroxy-2-naphthoic acid and the 3, 4-dihydroxythiophene methyl diformate are used as raw materials. And the molar ratio of the 2, 4-dihydroxy thiophene methyl dicarboxylate is (60-80): (5-40): (0.5-3). The corrosion-resistant thin film provided by the invention is excellent in mechanical property and corrosion resistance, and the corrosion-resistant pipe provided by the invention is high in combining capacity with the thin film and good in corrosion resistance.

The invention relates to a continuous production method of ultra-pure 2, 3, 4, 4 '-tetrahydroxybenzophenone, which comprises the following steps: completely dissolving p-hydroxybenzoic acid in high-boiling range petroleum ether, and completely dissolving pyrogallic acid in the high-boiling range petroleum ether; the preparation method comprises the following steps: adding a p-hydroxybenzoic acid solution and a pyrogallic acid solution into an ultra-pure continuous reactor group, adding boron trifluoride diethyl etherate into the ultra-pure continuous reactor group at a flowing speed, reacting at 110-140 DEG C, adding the obtained reaction solution into the next ultra-pure continuous reactor group, stirring in ice water, filtering, washing and recrystallizing to obtain the 2, 3, 4, 5-tetramethyl-3, 5-dihydroxybenzoic acid. According to the present invention, the reaction time is substantially shortened, the conversion rate is 70-80%, the purity of the obtained electronic product is more than or equal to 99.2%, the content of the metal ions such as sodium, aluminum, copper, iron, calcium, zinc and boron is less than or equal to 60 ppb, the reaction materials, the reaction temperature and the reaction rate are controllable, the reaction is sufficient, the yield of the obtained target product is stable, and the method can be used for continuous production.

The invention discloses a method for quantitatively detecting hydroxyl radicals in a soil suspension. Benzoic acid is used as a trapping agent of hydroxyl radicals, is captured at a benzene ring para-position within extremely short reaction time and is stably stored in a benzene ring-OH form, and the concentration of the hydroxyl radicals in the soil suspension to be detected can be accurately quantified through a standard curve of a multi-point external standard method by detecting the peak integral area of a sample. Compared with the existing method, the method has the advantages that the result reproducibility is good, and the detection limit can be as low as 0.58 mu g / L. And the adopted HPLC-MS / MS is used for quantitative analysis of p-hydroxybenzoic acid, has high response and can improve the detection accuracy.

The invention relates to the technical field of coatings, in particular to a graphene modified polyurethane coating with an electromagnetic shielding function. The coating is composed of deionized water, a graphene modified polyurethane emulsion, silver nanoparticles and an auxiliary agent, a synergistic modification system of hydroxylated graphene and p-hydroxybenzoic acid is introduced in a polyurethane prepolymerization stage, an organic-inorganic synergistic network with good interface compatibility is formed, the conductivity and electromagnetic shielding effect of the coating are remarkably improved through a formed compact conductive path, and meanwhile the flexibility and adhesive strength of polyurethane are kept. The coating is compact in structure, high in adhesive force, good in conductive continuity and excellent in electromagnetic shielding effect, and can be widely applied to the field of electromagnetic protection of electronic equipment shells, communication devices and aerospace equipment.

The invention discloses a high-temperature-resistant liquid crystal polymer substrate for ultrathin flexible display, which belongs to the technical field of flexible display and comprises a modified liquid crystal polymer and a functional additive dispersed in the modified liquid crystal polymer. The modified liquid crystal polymer is prepared by polymerizing a monomer composition, and is specifically prepared from 38 to 42 parts of p-hydroxybenzoic acid, 28 to 30 parts of 4, 4 '-biphenol, 5.6 to 6.0 parts of terephthalic acid, 4.4 to 5.0 parts of 2, 6-naphthalic acid, 2.7 to 3.3 parts of isophthalic acid, 9 to 11 parts of 2, 2-bis (3, 5-difluoro-4-hydroxyphenyl) hexafluoropropane, 4.5 to 5.5 parts of N, N'-dihydroxypyromellitic diamine, 9 to 11 parts of 9, 9-bis [4-(4-methoxycarbonyl phenoxy) phenyl] fluorene and 1, 2-bis (4-(4-methoxycarbonyl phenoxy) phenyl] fluorene. The component A is prepared from 5.5 to 6.5 parts of 1, 4-cyclohexanedimethanol; the functional additive comprises an azobenzene derivative, a hot acid generator and a hydrogen bond enhancer; through the synergistic effect of a specific monomer combination, a functional additive and an optimization process, the technical bottleneck that heat resistance, transparency, dimensional stability and flexibility of an existing material are difficult to consider at the same time is broken through.

The invention discloses a method for determining the content of p-hydroxybenzoic acid in a procaterol hydrochloride oral solution. The method comprises the following steps: (1) preparing chromatographic conditions of a high performance liquid chromatography; (2) taking a procaterol hydrochloride oral solution to be detected as a test solution; (3) dissolving a p-hydroxybenzoic acid reference substance in a solvent, and quantitatively diluting to prepare a reference substance solution for later use, wherein about 0.22 mu g of p-hydroxybenzoic acid is contained in each 1ml of reference substance solution; (4) measuring the test solution and the reference solution, respectively injecting the test solution and the reference solution into a liquid chromatograph, recording chromatograms, and calculating the concentration by peak area according to an external standard method, the detection wavelength being 254-300nm; the column temperature of the chromatographic column is 35-45 DEG C; the flow rate is 0.9 to 1.1 ml per minute; the sample injection volume is 20-100 [mu] l. According to the method, the separation degree of a p-hydroxybenzoic acid peak and an adjacent peak is good, interference generated by blank auxiliary materials and solvents can be effectively eliminated, and the method can be used for quality control of a final product of the procaterol hydrochloride oral solution.

The invention relates to the technical field of catalysts, in particular to a preparation method of an iron-cobalt oxide and Beta molecular sieve composite catalyst and application of the iron-cobalt oxide and Beta molecular sieve composite catalyst to demethoxylation of lignin derivative vanillic acid. Meanwhile, due to the interaction of iron and cobalt species, the acid site of the catalyst is enhanced, and adsorption and activation of a substrate are facilitated; the iron-cobalt oxide is combined with the Beta molecular sieve, and the reaction activity of demethoxylation is improved through cooperation of metal / zeolite; the Co0 / Fe0. 04Co0. 96O-Beta composite catalyst is used for a vanillic acid demethoxylation catalytic reaction, the reaction is performed for 2 hours under the condition of 0.4 MPa H2 and 0.4 MPa CO2, the substrate conversion rate reaches 96.07%, the p-hydroxybenzoic acid selectivity reaches 86.96%, and the target product yield is 83.54%.

The invention discloses a method for synthesizing gallic acid through double-cell catalysis of terephthalic acid and a strain of the gallic acid through double-cell catalysis of terephthalic acid. The method comprises the following steps: respectively constructing a protocatechuic acid transformation strain for expressing tphAa, tphAb, tphAc and tphB genes in a tphAB gene cluster and a gene tpaK for coding TPA transport protein, and a gallic acid transformation strain for expressing a gene pobA for coding p-hydroxybenzoic acid hydroxylase; bacterial cells of the protocatechuic acid transformation strain and the gallic acid transformation strain are used as catalysts to catalyze a substrate terephthalic acid to synthesize gallic acid. The protocatechuic acid transformed strain constructed by the invention assists terephthalic acid to enter cells by using transporter, so that the intracellular concentration of terephthalic acid is remarkably improved, and the conversion rate of gallic acid produced and synthesized by terephthalic acid is further improved.

The invention discloses high-performance LCP (Liquid Crystal Polymer) resin and a preparation method thereof, and relates to the technical field of LCP resin. According to the preparation method, p-hydroxybenzoic acid, p-tert-butylcatechol and 5-vinyl isophthalic acid are taken as key monomers, LCP base resin with a side chain containing double bonds and tert-butyl is synthesized, then the LCP base resin and alkenyl-terminated polyarylester are subjected to melt extrusion, and the high-performance LCP resin is prepared. According to the present invention, the polyarylester and the alkenyl-terminated polyarylester form the micro-cross-linked structure during the processing, such that the excessive orientation of the molecular chain is effectively inhibited, the anisotropy is reduced, the melt strength and the processability are significantly improved, and the obtained resin has characteristics of high mechanical property and improved toughness, and is especially suitable for preparing the high-performance LCP material.

The invention relates to the technical field of p-hydroxybenzoic acid preparation, and discloses a p-hydroxybenzoic acid preparation method, which comprises: 1, mixing benzoic acid and a potassium hydroxide solution to form a potassium phenolate solution; 2, in an alkaline aqueous solution system, carrying out a directional hydroxylation reaction with a hydroxylation reagent in the presence of a phase transfer catalyst to generate potassium p-hydroxybenzoate; and step 3, converting the potassium p-hydroxybenzoate into p-hydroxybenzoic acid through acidification treatment. Compared with the prior art, the preparation method of p-hydroxybenzoic acid provided by the invention has the advantages of high efficiency, environmental protection and suitability for industrial production. The method comprises the following steps: reacting a potassium phenolate solution under an alkaline condition to generate potassium p-hydroxybenzoate under the catalysis of a phase transfer catalyst, and acidizing to obtain p-hydroxybenzoic acid. The method has the advantages of mild reaction conditions, high yield, few byproducts, easiness in industrial production and the like.

The invention provides a herbicide for preventing and treating cyperus rotundus in cooperation with glyphosate. The herbicide is prepared from bacillus velezensis fermentation liquor, phenolic acid and glyphosate. The phenolic acid comprises any one or a combination of more of p-coumaric acid, cinnamic acid, p-hydroxybenzoic acid and caffeic acid. The bacillus velezensis fermentation liquor and phenolic acid components are introduced and form a synergistic effect with the glyphosate, so that the dosage of a single dosage of the glyphosate is reduced, the control effect is guaranteed, meanwhile, the potential pressure of chemical pesticide input on the ecological environment is reduced, and the environmental compatibility of a weeding system is improved.

This invention discloses a strain that degrades various lignin-derived aromatic compounds and its application in detoxification of hydrolysate. The strain is classified as *Rhodococcus ethereans*. Rhodococcus ether-eating Strain N1, deposited at the China Center for Type Culture Collection (CCTCC) on August 11, 2022, with accession number CCTCC NO: M 20221270, can degrade p-hydroxybenzoic acid, p-coumaric acid, ferulic acid, vanillin, coniferyl alcohol, and syringaldehyde. After lignin depolymerization, derivative phenolic inhibitors are formed, mainly divided into three types: S-type (syringaldehyde), G-type (ferulic acid), and H-type (p-coumaric acid), which affect the fermentation of the strain. The Rhodococcus bacterium in this invention can efficiently degrade SGH-type monomers, achieving a removal efficiency of up to 68.4% when applied to the biological detoxification of hydrolysate inhibitors. Strain N1 has significant application value in improving the conversion efficiency of lignocellulose hydrolysate and reducing the detoxification cost in industrial production.

This invention discloses an ABS surface scratch repair coating and its preparation method, relating to the field of coating technology. The ABS surface scratch repair coating is prepared by reacting 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide with formic acid to obtain intermediate 1; reacting intermediate 1 with diethyl maleate to obtain intermediate 2; reacting intermediate 2 with ethylenediamine to obtain a polyamino phosphorus-containing curing agent; reacting p-hydroxybenzoic acid with 2-chlorocyclopentanone to obtain cyclopentanone benzoate; reacting nano-cerium dioxide sequentially with 3-chloropropyltrimethoxysilane and cyclopentanone benzoate to obtain modified nano-cerium dioxide; and mixing epoxy resin, polyamino phosphorus-containing curing agent, puerarin, and modified nano-cerium dioxide with acetone as a diluent to obtain the ABS surface scratch repair coating. The ABS surface scratch repair coating prepared by this invention has superior weather resistance and flame retardant properties.

The invention belongs to the field of high-frequency communication materials, and particularly discloses a Low-alpha ray spherical alumina / liquid crystal polymer 5G base station substrate material, which is characterized by comprising a liquid crystal copolymer matrix and a Ce < 3 + > doped spherical alumina filler, the liquid crystal copolymer matrix is prepared from three comonomers, namely 60 to 68 mol percent of p-hydroxybenzoic acid, 20 to 24 mol percent of 5, 5 '-dithiobis (2-nitrobenzoic acid) and 12 to 16 mol percent of 4-(5-amino-6-hydroxy-2-benzoxazole)-benzoic acid; the surface of the Ce < 3 + >-doped spherical alumina filler is sequentially coated with a Bi2Te3-xSex topological insulating layer and a phosphate silane grafting layer, wherein x is equal to 0.12-0.18. According to the Low-alpha ray spherical aluminum oxide / liquid crystal polymer 5G base station substrate material, the alpha ray shielding rate is larger than or equal to 99.95%, the heat conductivity is larger than or equal to 3.35 W / mK, the dielectric loss factor tan delta is smaller than 0.00014 under 28 GHz, and the strict requirements for high frequency, high reliability and the like of a substrate in 5G millimeter wave antenna application can be met.

The invention discloses a method for detecting the content of p-hydroxybenzoic acid in an ebastine oral solution. The method comprises the following steps: step 1, setting chromatographic conditions; 2, preparing a solution; step 3, determination; step 4, limiting; the method is simple, convenient, rapid, high in accuracy and good in specificity, can measure the content of p-hydroxybenzoic acid in the ebastine oral solution, and is suitable for quality research and control of the ebastine oral solution.

The present application relates to the field of polyester fiber, disclose a kind of melt direct spinning antimony-free polyester fiber and its preparation method, the polyester fiber is made by following method: with terephthalic acid and ethylene glycol as reaction raw material, add antibacterial agent, antistatic modifier and titanium catalyst, after esterification reaction and pre-polycondensation process, further through final polycondensation reaction and spinning process obtain;Antibacterial agent is synthesized antibacterial intermediate using 2-pyridine methanol and decyl bromide, then isophorone diisocyanate is used as connecting agent, antibacterial intermediate is grafted with chitosan, and further grafted with p-hydroxybenzoic acid;Antistatic modifier is obtained by grafting double bond graphene oxide, methacryloyloxyethyl trimethylammonium chloride and methoxy polyethylene glycol acrylate copolymerization, the present application is added by antibacterial agent and antistatic modifier, endows polyester fiber with excellent fracture toughness, hygroscopicity and antistatic performance is good, simultaneously has excellent antibacterial property.

The invention relates to the technical field of high-performance polymer fiber manufacturing, in particular to a low-processing-viscosity liquid crystal polyarylester fiber and a preparation method thereof.The preparation method comprises the steps that S1, p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid serve as monomers, and an acetylation reaction is conducted in the presence of an acetylation reagent and a catalyst; the preparation method comprises the following steps: firstly, preparing LCP resin, then carrying out melt polycondensation reaction, adding 6-acetoxy-2-naphthoic acid at the later stage of the melt polycondensation reaction, stirring and dispersing, discharging, cooling and granulating to obtain the LCP resin; and S2, carrying out melt spinning and heat treatment on the LCP resin to obtain the liquid crystal polyarylate fiber. According to the preparation method, the melt processing viscosity of the resin can be remarkably reduced, the production smoothness is improved, the heat treatment time is shortened, the production energy consumption is reduced, the high molecular weight potential of the resin in spinning processing is not influenced, and the liquid crystal polyarylate fiber is ensured to have very good strength performance.

The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing and purifying p-hydroxybenzoic acid. The method comprises the following steps: S1, mixing p-cresol and an acid-base bifunctional catalyst, adding the mixture into an ethanol solution, stirring, mixing and reacting, filtering, and separating the acid-base bifunctional catalyst to obtain filtrate; s2, adsorbing the filtrate obtained by the reaction in the step S1 by using an activated carbon column, and then adjusting the pH value by using dilute sulphuric acid to obtain acidified filtrate; and S3, carrying out anti-solvent assisted gradient crystallization treatment on the acidified filtrate obtained in the step S2, carrying out vacuum filtration to separate mother liquor, and repeatedly leaching with a precooled acetone solution to obtain p-hydroxybenzoic acid. According to the method, the spatial isolation type acid-base bifunctional catalyst, the ethanol-water mixed solvent and the activated carbon column are combined for impurity adsorption and anti-solvent gradient crystallization, the purification process is simplified, H2O2 serves as a clean oxidizing agent, ethanol, acetone and the catalyst can be recycled and regenerated, and the coconut shell activated carbon carrier is cheap and renewable.

The invention relates to the technical field of methylparaben synthesis, in particular to a synthetic method of methylparaben. The synthetic method of methylparaben comprises the following steps: taking p-hydroxybenzoic acid and methanol as raw materials, adding a catalyst material, carrying out heating treatment, and carrying out a heating reflux reaction; and after the methanol solution is distilled out, continuing to add methanol and carrying out a stirring reaction, repeating the steps, recovering the methanol solution for multiple times until the p-hydroxybenzoic acid is completely reacted, stopping the reaction, filtering, collecting filtrate, recovering the catalyst, distilling to remove methanol, and separating out crystals to prepare the methylparaben. The catalyst material comprises a strong acid cation exchange resin. According to the method, the strong acid type cation exchange resin is used as a catalyst, and water is distilled in the synthesis process, so that water in a reaction system is continuously removed, reaction equilibrium is continuously shifted rightwards, and the yield of methylparaben is increased. And the concentrations of methanol and the catalyst are almost unchanged in the later reaction stage, and the reaction rate is not affected.

The invention discloses an efficient synthesis process of a glufosinate-ammonium intermediate, and belongs to the technical field of synthesis of organophosphorus compound intermediates. The process comprises the following steps: etching foam copper particles with nitric acid to make their surfaces rougher; subjecting the foam copper particles to chemical nickel plating to generate a nickel layer with corrosion resistance; and performing a secondary etching process with urea to grow a tightly contacted nickel hydroxide layer on the surface. The surface of the nickel hydroxide layer has abundant hydroxyl (-OH) functional groups, and in situ generating an organic skeleton with porosity and adsorption capacity on the surface through the hydroxyl groups. The organic skeleton is carbonized on the surface to obtain a nickel-plated foam copper with high strength and a carbon layer wrapped on the surface. The hydroxyl groups remaining on the surface are combined with carboxyl groups of p-hydroxybenzoic acid to generate a metal skeleton with catalytic activity in situ on the surface, thereby improving the catalytic efficiency and service life of the catalyst, improving the productivity of the glufosinate-ammonium intermediate, and improving the utilization rate of phosphorus trichloride.

This invention discloses a methane inhibitor based on plant functional components and its application. The inhibitor, by mass fraction (100%), comprises the following raw materials: 1.5-6% p-hydroxybenzoic acid, 0.4-2.4% astragaloside, 5-40% polyethylene glycol 4000, and 81.6-99.999% bentonite. The methane inhibitor provided by this invention uses p-hydroxybenzoic acid and astragaloside as active ingredients. Through their synergistic effect, it effectively inhibits the activity of methanogenic bacteria and the methane production pathway in the rumen of ruminants, while simultaneously improving the rumen fermentation pattern. The above-mentioned methane inhibitor uses natural plant-derived active ingredients, is safe, non-toxic, environmentally friendly, and has a simple preparation process suitable for large-scale production.