73 results about "Hydroxyacetic Acids" patented technology

The invention belongs to the technical field of organic synthesis, and provides a preparation method of a cationic lipid compound, which comprises the following steps: (1) reacting 1, 5-dihalopentane, 2-tert-butyl glycolate and alkali to obtain a product G; (2) hydrolyzing the product G under an acidic condition to obtain a product H; (3) carrying out esterification reaction on the product H, the raw material C, 4-dimethylaminopyridine and a condensing agent in dichloromethane to obtain a product J; and (4) carrying out amination reaction on the product J, the raw material L and alkali in acetonitrile to obtain the cationic lipid compound. Compared with the prior art, the method has the relatively remarkable advantages that when the first part of halogenated long-chain alkyl ester H is synthesized by the method, 1, 5-dihalopentane and 2-tert-butyl glycolate are used as raw materials, the halogenated long-chain alkyl ester J is synthesized by a simple method, the product is obtained at a higher yield in synthesis, and the method is suitable for kilogram-level production. The route synthesis only comprises four steps of chemical reactions, and is suitable for industrial production.

The invention discloses a medical pressure-sensitive adhesive patch based on citric acid, a preparation method and application, the medical pressure-sensitive adhesive patch is composed of an adhesion layer and an anti-adhesion layer, and the thickness ratio of the adhesion layer to the anti-adhesion layer is 1: 1-100: 1; the adhesion layer is obtained by polymerizing a citric acid unit and a polyhydroxy compound unit; the hydrophobic high-molecular polymer is selected from at least one of a polylactic acid-glycolic acid copolymer, polylactic acid, polyurethane and polyether urethane. According to the preparation method, three carboxyl groups in the citric acid not only can be used for esterification reaction with polyhydric alcohols to form a network, but also can provide excellent adhesive force for contact between the adhesive patch and the tissue surface through electrostatic interaction or hydrogen-bond interaction. The anti-sticking layer prepared from the hydrophobic high-molecular polymer can effectively resist invasion of external moisture and bacteria, so that the service time of the adhesive patch is prolonged; meanwhile, the anti-sticking layer can also play a supporting role, so that the mechanical strength of the adhesive tape is improved.

The invention discloses a lumepirone long-acting microsphere sustained-release preparation without a release stagnation period in an early stage, which comprises a lumepirone active ingredient and a medicinal polymer auxiliary material in a mass ratio of (1: 4)-(1: 1), the medicinal polymer auxiliary material is at least one of glycolide-lactide copolymers with the weight-average molecular weight of 5000-150000 Da, and the molar ratio of lactic acid units to glycolic acid units of the glycolide-lactide copolymers is (50: 50)-(95: 5). The lumepirone long-acting microsphere sustained-release preparation without a release arrest phase in the early stage is obtained by specially limiting drying conditions in liquid and medicinal polymer auxiliary materials, the release of the lumepirone long-acting microsphere sustained-release preparation can be maintained for 2 weeks to 1 month without oral administration of the long-acting sustained-release microspheres of lumepirone capsules, the safety and effectiveness of the medicine are met, and the sustained-release preparation is suitable for clinical application. Meanwhile, the problems of early-stage long-time stagnant release and early-stage burst release of the long-acting microsphere preparation can be solved, the compliance can be effectively improved, convenience is provided for patients to the maximum extent, and the economic cost is reduced.

The application belongs to the technical field of pharmaceutical chemistry, and particularly relates to clofazimine-organic acid co-crystals, a preparation method and application thereof. The clofazimine-organic acid co-crystal is one of clofazimine-ferulic acid monohydrate co-crystal, clofazimine-ferulic acid co-crystal, clofazimine-glutaric acid co-crystal, clofazimine-glycolic acid co-crystal (CFZ-GA 1:1), clofazimine-glycolic acid co-crystal (CFZ-GA 1:1.5), clofazimine-salicylic acid co-crystal, clofazimine-L-aspartic acid co-crystal, clofazimine-L-pyroglutamic acid co-crystal, clofazimine-gallic acid co-crystal, clofazimine-succinic acid co-crystal, clofazimine-tartaric acid co-crystal and clofazimine-DL-mandelic acid co-crystal. The clofazimine-organic acid co-crystal provided by the application significantly improves the solubility and fluidity of clofazimine, thereby improving the bioavailability of clofazimine, and has a broad medicinal prospect.

The application relates to the technical field of organic synthesis, in particular to a catalyst, a preparation method thereof and a preparation method of methyl glycolate. The preparation method of the catalyst comprises the following steps: loading a copper salt and a silver salt on a carrier to obtain a catalyst precursor, wherein the material of the carrier comprises silicon dioxide; performing electromagnetic radiation treatment on the catalyst precursor to obtain a modified catalyst precursor; and performing reduction treatment on the modified catalyst precursor, so that the copper salt loaded on the carrier is reduced into elemental copper, and the silver salt loaded on the carrier is reduced into elemental silver. The preparation method can improve the DMO conversion rate and the MG selectivity.

The invention discloses a preparation method of a sodium lauryl glycol carboxylate compound, which comprises the following specific steps: adding 1, 2-epoxydodecane and glycolic acid into a first reaction flask containing a solvent, and carrying out heating reaction under the action of a large-steric-hindrance catalyst to obtain lauryl glycol acetic acid; wherein the solvent is cyclohexane, normal hexane or methylbenzene, and the large steric hindrance catalyst is tri (pentafluorophenyl) borane; and S3, adding the lauryl glycol acetic acid prepared in the step S1 into a second reaction flask containing water, and adjusting the pH value of the solution in the second reaction flask to 8.5-11.5 by using a certain amount of sodium hydroxide solution to prepare lauryl glycol sodium carboxylate, namely the target compound. According to the preparation method disclosed by the invention, the single selectivity of the synthesis process is improved, so that the purity and yield of the sodium lauryl glycol carboxylate compound synthesized by the route are greatly improved, and the product becomes better and better in application.

A PLG copolymer material, called a PLG(p) polymer material adapted for use in a controlled release formulation for a bioactive material is provided, wherein the formulation exhibits a reduced initial burst effect when introduced into the tissue of a patient in need thereof. A method of preparing the PLG copolymer material is also provided, as are methods of use.

The invention relates to the technical field of modified calcium carbonate, in particular to modified calcium carbonate, which comprises the following structures: an inner core: lithium battery recycled calcium carbonate slag, which comprises 1.2-1.8 wt% of Li2CO3 and 0.5-1.2 wt% of MgCO3; the middle layer is a polydopamine (PDA) coating film, the thickness of the polydopamine (PDA) coating film is 50-80 nm, and the polydopamine (PDA) coating film is used for providing active amino (-NH2); the shell is a fluorine-containing silane and polylactic acid-glycolic acid copolymer (PLGA) composite layer, the grafting rate is larger than or equal to 90%, and the molar ratio of lactic acid to glycolic acid of PLGA is 75: 25. Quantized data of performance improvement and dispersibility are as follows: the oil absorption value is 18 ml / 100 g (compared with 28-32 ml / 100 g in the prior art), and the bulk density is 0.25 g / cm < 3 > (loose agglomeration). Functions are as follows: flame retardance: the oxygen index (LOI) reaches 34.5% (no flame retardance exists in the prior art); the antibacterial property is that the Escherichia coli inhibition rate is 99.2% (ASTM E2149 standard), and the environmental protection property is that 2.8 tons of limestone can be reduced for each ton of products, and 1.2 tons of CO2 emission can be reduced.

The present application relates to the technical field of purification, and discloses a dehydrated fiber membrane and a preparation method and application thereof.A dehydrated fiber membrane, wherein the dehydrated fiber membrane comprises a hollow fiber membrane base, a first silane membrane, a first hydrophilic membrane and a first modified membrane are coated on the inner surface of the hollow fiber membrane base from inside to outside, and a second silane membrane, a second hydrophilic membrane and a second modified membrane are coated on the outer surface of the hollow fiber membrane base from inside to outside; the first hydrophilic membrane and the second hydrophilic membrane each independently contain an amide group; the first modified membrane contains a sulfonamide group; and the second modified membrane contains a pyrrole group, a sulfhydryl group and / or a sulfide group.The dehydrated fiber membrane can effectively reduce the content of oligomers in the hydroxyacetic acid dehydration process.

The application provides a bathroom secondary cleaning agent and relates to the technical field of sanitary products. The bathroom secondary cleaning agent comprises A material and B material. The A material comprises rose-sour powder; the B material comprises, in percentage by mass, 0.1-5% of a hydrophilic group modified polymer, 1-5% of a modified acrylamide polymer, 0.1-2% of glycolic acid, 0.5-3% of a Zanthoxylum bungeanum leaf extract, 0.5-4% of a propoxy compound and the balance of water. The rose-sour extract contains various organic acids, and the organic acids cooperate with the modified acrylamide polymer, the glycolic acid and the propoxy compound in the liquid reagent, so that various components such as scale, oil stains, rust stains and soap stains in the bathroom can be effectively removed, and cleaning is easier. In addition, the cleaning agent is added with the Zanthoxylum bungeanum leaf extract, and has the functions of sterilization and deodorization.

The invention belongs to the field of high polymer materials, particularly relates to a novel high polymer alloy material and a master batch prepared from the novel high polymer alloy material, and further relates to application of the high polymer alloy material and the master batch. The polymer alloy material is a PETX / PBAT blended composition, and PETX is copolyester of ethylene glycol terephthalate and glycolic acid and / or lactic acid. According to the polymer alloy material and the master batch, excellent balance of rigidity and toughness can be achieved, the raw material cost and the process complexity are reduced, the soil moisture preservation performance of the material is improved, and meanwhile the application direction of PET plastic recycling is effectively expanded.

The invention provides a preparation method for coproduction of hydroxyethyl piperazine and triethylene diamine, which comprises the following steps: by taking dimethyl oxalate directly prepared from coal as a key raw material, carrying out catalytic hydrogenation reduction reaction on the dimethyl oxalate to obtain alpha-methyl glycolate; then the alpha-methyl glycolate and piperazine are subjected to a nucleophilic acyl substitution reaction, and an intermediate product 2-hydroxy-1-(piperazine-1-yl) ethanone is generated; and finally, carrying out hydrogenation reduction on the intermediate product under the action of a catalyst to synchronously obtain target products, namely hydroxyethyl piperazine and triethylene diamine. According to the method, double products of hydroxyethyl piperazine (medicine and dye intermediates) and triethylene diamine (a polyurethane catalyst and a rubber accelerator) are synchronously generated, the total yield of hydroxyethyl piperazine reaches 72% or above, the yield of triethylene diamine reaches 70% or above, the two products are high-added-value fine chemical products, and compared with a single product route, the method has the advantages that the yield is high, and the cost is low. The economic benefit of unit raw materials can be greatly improved, and the resource utilization rate is maximized. The invention belongs to the technical field of organic synthesis.

RENAISSANCE HSP3 - a unique complex of active ingredients providing hydration, regeneration, and skin protection. To achieve the best results in improving the appearance and condition of the skin, an active complex of multi-directional ingredients was designed and created. H - Hyaluronic Acid INCI: Sodium Hyaluronate, Hydrolyzed Hyaluronic Acid P - Peptide INCI: Acetyl Hexapeptide-8 S - Stem Cells INCI: Haberlea Rhodopensis Leaf Extract The combination of the well-researched ingredients described above results in a complex that provides: - Hydration - Anti-wrinkle - Regenerative - Protective - Antioxidant effects The use of this complex in cosmetic products for facial and body care will result in safe and highly effective products.

The invention provides a resourceful treatment method for glycolic acid wastewater, and belongs to the technical field of wastewater resourceful utilization. The method comprises the following steps: carrying out reduced pressure distillation on glycolic acid wastewater, and carrying out solid-liquid separation to obtain a first concentrated solution; adding an organic solvent into the first concentrated solution, carrying out a reflux dehydration reaction, and after the reaction is completed, cooling to room temperature to obtain a second concentrated solution; performing solid-liquid separation on the second concentrated solution to obtain solid salt and organic phase filtrate; and distilling the organic phase filtrate, separating and recovering the organic solvent, and returning to the reflux dehydration step for recycling, thereby obtaining the distillation residue, namely the glycolic acid solution. The method can effectively separate solid salt and glycolic acid, turns waste into wealth, realizes resource utilization of wastewater, and has remarkable environmental, economic and social benefits.

The application belongs to the technical field of cosmetics, and discloses a red fading repair composition, a preparation method thereof and application. The preparation method of the red fading repair composition comprises the following steps: (1) crushing oat kernels, sieving and extracting with pure water to obtain oat kernel extract; (2) adding fresh green beans to a glycerol / water mixed solution containing hydroxyacetic acid, crushing and dispersing with a high-speed homogenizer to obtain a homogenate without particles, and stirring and extracting under low-temperature conditions of 4-10 DEG C to obtain green bean seed extract; and (3) uniformly mixing glycerophosphoinositol choline salt, oat kernel extract and green bean seed extract according to a mass ratio of 0.1-2:10-40:50-80 to obtain the red fading repair composition. The red fading repair composition of the application uses green bean seed extract prepared by a specific process as a main raw material, and can achieve a significantly improved red fading repair effect through the synergistic effect of oat kernel extract and GPI.

This invention provides a copper etching solution, its preparation method, etching method, and application. The copper etching solution comprises 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid. The copper etching solution of this invention exhibits good etching properties for copper and minimal damage to nickel-chromium alloys.

This invention relates to the field of coating technology, specifically to a printing coating for colored paper and its preparation method. In the preparation process, this invention incorporates dithiol dihydroxyacetic acid to increase the crosslinking points of the system, and trimethylolpropane tris(2-methyl-1-azacyclopropane propionate) containing an unstable aziridine three-membered ring to improve the degree of crosslinking. It also introduces isoborneol methacrylate to reduce internal stress, effectively balancing the crosslinking density and volume shrinkage of the system, resulting in a coating with excellent adhesion. Furthermore, this invention adds the bifunctional monomer 1,6-hexanediol diacrylate to make the network structure more uniform and provide anti-photooxidation properties, making the system less prone to oxidative discoloration. The addition of tripropylene glycol diacrylate reduces the risk of yellowing caused by small molecule migration. Therefore, the coating obtained in this way has significant anti-yellowing effects, preventing color distortion of colored paper and maintaining the appearance stability of the colored paper.

The invention relates to a regeneration method of a vanadium redox flow battery electrolyte, and the method comprises the following steps: carrying out reduction treatment on a to-be-treated electrolyte through a reducing agent so as to adjust the valence state of vanadium ions in the to-be-treated electrolyte; the reducing agent comprises one, two or more of acid compounds and carbohydrate compounds, the acid compounds comprise oxalic acid, acetic acid, glycolic acid, formic acid, citric acid and maleic acid, and the carbohydrate compounds comprise glucose, fructose, galactose, lactose, maltose, sucrose and cellulose. According to the regeneration method of the vanadium redox flow battery electrolyte, the reducing agent is introduced to perform reduction treatment on the vanadium ions in the electrolyte, so that the effective recovery of the battery capacity can be realized.

The present invention provides terbinafine hydrochloride tablets, comprising terbinafine hydrochloride, a disintegrant, a binder, a polymethacrylic acid resin, glycolic acid, a glidant, and a lubricant. Compared with the prior art, the present invention uses glycolic acid, an organic acid, as a pH regulator to maintain an acidic pH environment throughout the tablet, thereby ensuring product stability throughout its storage cycle. Furthermore, polymethacrylic acid resin is used as a filler to improve the compressibility of the material, ensuring that the product meets hardness requirements throughout its storage cycle, with quality comparable to that of a tablet at day 0.

The invention discloses a continuous synthesis method and device of MSH.The continuous synthesis method of MSH comprises the steps that 2, 4, 6-trimethylbenzenesulfonyl chloride and an acid binding agent are dissolved in a first solvent to form a first solution, N-hydroxy-acetic acid imino ethyl ester is dissolved in the first solvent to form a second solution, and the second solution is dissolved in a third solvent to form a second solution; respectively pumping the first solution and the second solution into a first reaction container for reaction to obtain a first effluent; the first effluent, perchloric acid and a second solvent respectively flow into a second reaction container for reaction, and second effluent containing MSH is obtained. According to the present invention, the flow chemical design idea is adopted to continuously synthesize MSH, the stability of the raw material is good, the intermediate high-energy product and the high-energy end product can be rapidly utilized, and the accumulation and the long-time retention are effectively avoided so as to effectively avoid the decomposition and reduce the safety risk; the device disclosed by the invention is simple in structure, suitable for being matched with a production line of MSH derivative products, and convenient for synthesizing MSH at present.

A nanofiber matrix material for application to a wound, comprising at least one layer of nanofiber. The nanofiber comprises poly-p-dioxanone (PDO), a surfactant, and one or more of the following polymers: poly(lactic-co-glycolic acid) (PLGA), polyglycolic acid (PGA), poly(glycolide-co-caprolactone) (PGCL), poly(lactide-co-caprolactone) (PLCL), polycaprolactone (PCL), polylactic acid (PLA), and poly(4-hydroxybutyric acid) (P4HB). The nanofiber matrix material is easy to prepare and maintains high thermal stability during preparation and use. Moreover, the material is highly hydrophilic; the material can rapidly draw exudate from a wound and help the wound heal faster.

Method for producing a sterile oxybutynin-containing composition in a preferably ready-to-use piston syringe, in particular a disposable piston syringe, and / or for producing a preferably ready-to-use, sterile piston syringe filled with an oxybutynin-containing composition, in particular a disposable piston syringe, wherein the piston syringe has a syringe body on one side and a syringe piston with a piston stopper on the other, wherein the syringe body is made of polypropylene, and wherein the final oxybutynin-containing composition obtained after completion of the process, in particular after process step b), is formed as a sterile aqueous composition, in particular a terminally sterilized composition, and has the following specification requirements (i) and (ii) and / or (iii), preferably (i), (ii) and (iii): (i) specified concentration of oxybutynin, preferably in the form of the hydrochloride, with a specified deviation of not more than ± 5%, based on the concentration of oxybutynin, (ii) specified specification pH value with a specified deviation of not more than ± 0.5 pH units, (iii) specified maximum quantity of oxybutynin degradation product(s), in particular reactively generated oxybutynin degradation product(s), preferably hydrolytically and / or oxidatively generated oxybutynin degradation product(s), preferably phenylcyclohexylhydroxyacetic acid; the procedure includes the following steps: a) Providing an oxybutynin-containing starting composition in the piston syringe and / or filling the piston syringe with an oxybutynin-containing starting composition and subsequently b) Heat sterilization, in particular steam sterilization, preferably steam sterilization, preferably terminal sterilization, of the oxybutynin-containing starting composition in the syringe and / or the syringe filled with the oxybutynin-containing starting composition to obtain the sterile oxybutynin-containing final composition in the preferably ready-to-use syringe and / or to obtain the preferably ready-to-use, sterile syringe filled with the oxybutynin-containing composition, wherein the migration and / or incorporation of the oxybutynin into the syringe body and / or the plunger stopper occurring in the process, in particular in process step b), and / or the degradation of the oxybutynin occurring in the process, in particular in process step b), in particular the reactive degradation of the oxybutynin, preferably the hydrolytically and / or oxidatively induced degradation, preferably the degradation to phenylcyclohexylhydroxyacetic acid, is controlled and / or compensated in such a manner and with the proviso that that the sterile oxybutynin-containing final composition obtained after carrying out process step b) meets the previously mentioned specification requirements (i) and (ii) and / or (iii), preferably (i), (ii) and (iii), and that the sterile oxybutynin-containing final composition is obtained in the preferably ready-to-use piston syringe or the preferably ready-to-use, sterile piston syringe filled with the oxybutynin-containing final composition, wherein the migration and / or incorporation of the oxybutynin into the syringe body and / or the plunger stopper occurring in the process, in particular in process step b), and / or the degradation occurring in the process, in particular in process step b), in particular the reactive degradation of the oxybutynin, preferably the hydrolytically and / or oxidatively caused degradation of the oxybutynin, preferably the degradation to phenylcyclohexylhydroxyacetic acid, is controlled and / or monitored, in particular prevented and / or minimized and / or compensated for, by at least one of the following measures and / or steps (1), (2), (3) and / or (4): (1) Adjustment and / or use of an increased concentration and / or amount of oxybutynin, preferably in the form of the hydrochloride, in the initial composition compared to the specified concentration and / or amount of oxybutynin, preferably in the form of the hydrochloride; (2) Adjustment of the pH value of the initial composition to a value that differs from the specified pH value, in particular an increased pH value; (3) Setting and / or selecting the sterilization conditions, in particular selected from the group consisting of sterilization type, sterilization duration, sterilization temperature, sterilization pressure, sterilization atmosphere and combinations thereof, preferably setting and / or selecting the F0 value of the sterilization; (4) Equipment and / or treatment, in particular coating, of the syringe body, preferably the inner wall of the syringe body, and / or the plunger stopper with at least one migration- and / or degradation-reducing agent.

The application provides a kind of double-loading microcapsule containing pyraclostrobin and brassinolide and its preparation method and application, and the double-loading microcapsule includes core material and wall material, and the wall material covers the core material;The core material includes pyraclostrobin and 24-epibrassinolide, and the wall material includes polylactic acid-hydroxyacetic acid copolymer and hydroxypropyl methyl cellulose phthalate, and the mass ratio of polylactic acid-hydroxyacetic acid copolymer, hydroxypropyl methyl cellulose phthalate is (40-50):(90-100);The application uses polylactic acid-hydroxyacetic acid copolymer and hydroxypropyl methyl cellulose phthalate with suitable mass ratio as wall material, combined with the preferred preparation method, so that the drug loading of microcapsule and the drug encapsulation efficiency are high, the drug diffusion rate can be effectively controlled, the sustained-release effect is good, and the double-loading microcapsule particle size is suitable, the effective period is long, and the preparation method is simple, so that the prepared double-loading microcapsule particle size distribution is uniform, without damage and coating phenomenon.

The invention relates to a poly-L-lactic acid microsphere used for a drug delivery system and having a controllable degradation rate and a preparation method and application thereof.The preparation method comprises the steps that an oil-phase organic solution is added into an emulsifier aqueous solution through an SPG film to be stirred for a reaction, and a poly-L-lactic acid microsphere crude product is obtained; sequentially mixing and reacting the L-polylactic acid microsphere crude product with a sodium hydroxide solution and a polylysine solution, washing and freeze-drying to obtain L-polylactic acid microspheres; a solute in the oil-phase organic solution comprises poly-L-lactic acid and a lactic acid-glycolic acid-polyvinyl alcohol block copolymer. The poly-L-lactic acid microsphere material obtained through a specific preparation process has good stability and biocompatibility, is controllable in degradation rate, and is suitable for preparing a drug delivery system, so that the drug curative effect is improved, and the drug administration frequency is reduced.

The application discloses a kind of for nuclear power plant two loop systems chemical cleaning agent and cleaning method, belong to nuclear power plant equipment chemical cleaning technical field.The cleaning agent is by cleaning main agent ethylenediaminetetraacetic acid, cleaning auxiliary agent (citric acid and / or glycollic acid), corrosion inhibitor N-108, pH regulator ammonia water, reducing agent (hydrazine hydrate or D-sodium isoascorbate), organic silicon defoaming agent and solvent (deionized water or desalted water) compound is formed.The cleaning agent cleaning stage is carried out at pH 5.5~6.5, temperature 110~130 DEG C;Passivation stage is completed by supplementing ammonia water at pH 8.5~9.5, temperature 80~95 DEG C.The cleaning agent of the application has high dissolution rate (up to 96.5%) to common scale type such as Fe3O4, has very low corrosion rate (<0.005 g / m 2 ·h) to austenitic stainless steel and nickel-based alloy, and seamless conversion of cleaning and passivation can be realized by pH adjustment, the operation process is simple, the waste liquid amount is less, the environmental protection is good, and the safety, efficient operation of nuclear power unit two loop system can be effectively guaranteed.

The invention discloses a preparation method of (R)-2-(3, 5-difluorophenyl)-2-glycolic acid, which comprises the following steps: 1, adding 2-(3, 5-difluorophenyl)-2-glycolic acid, (R)-(+)-1-phenylethylamine and acetone into a first solvent, and reacting to obtain a resolution salt crude product; 2, adding the resolution salt crude product into a second solvent, and reacting to obtain a resolution salt refined product; and step 3, adding the resolution salt fine product into water for dissolving, adding a third solvent, dropwise adding acid to adjust the pH value, layering, extracting a water layer once, combining organic layers, concentrating under reduced pressure, dropwise adding n-heptane, and crystallizing to obtain the (R)-2-(3, 5-difluorophenyl)-2-glycolic acid. According to the method, the raw materials and auxiliary materials are easy to obtain, the process operation is simple, the reaction condition is mild, the process yield is high, and the method is suitable for industrial production.

The invention discloses a gas well potential tapping and yield increasing composite technology, and relates to the technical field of petroleum and natural gas development, the gas well potential tapping and yield increasing composite technology comprises the following three steps: S1, plugging removal liquid (18-22% of composite chelating acid, 0.6-1.0% of a nanometer surfactant, 0.4-0.7% of a biological enzyme preparation and the balance of formation water, and the chelating acid is prepared from glycolic acid, EDTA disodium and ammonium fluoride according to the ratio of 18-22: 6-8: 4-7); s2, performing 3-5 stages of fracturing circulation, and injecting prepad fluid, sand-carrying fluid and a temporary plugging agent at each stage; and S3, supercritical gas is injected step by step, the initial pressure is 0.65-0.75 times of formation pressure, the final pressure is 1.3-1.45 times of formation pressure, and the pressure is increased by 0.02-0.03 MPa / min. According to the invention, pre-blocking removal and multi-stage temporary blocking fracturing are cooperated, a complex fracture net is made by means of a compound agent, pulse blocking removal and improvement of liquid spreading, and a bi-component temporary blocking agent and modified ceramsite; a desorption activation program is combined with controllable gradient supercritical gas injection, mixed gas activates adsorption gas, supercritical gas channeling prevention is controlled, real-time monitoring is carried out, traditional pain spots are broken, the recovery rate of residual gas is increased, and the stable production period of a gas well is prolonged.

The application discloses a household compostable polylactic acid-coated paper and a manufacturing process thereof. The polylactic acid composite material is coated on the surface of a base paper layer, and the cellulose nanocrystal is coated on the surface of the polylactic acid composite material to form the polylactic acid-coated paper. The polylactic acid composite material comprises the following components in parts by weight: 80-120 parts of modified polylactic acid, 10-15 parts of polyethylene glycol, 6-13 parts of chitosan, 3-8 parts of a chain extender, 6-9 parts of a lubricant, 4-8 parts of an antistatic agent and 3-7 parts of an antioxidant. The modified polylactic acid is obtained by blending and modifying polylactic acid-hydroxyacetic acid copolymer and polylactic acid. The weight ratio of the polylactic acid-hydroxyacetic acid copolymer and the polylactic acid is 0.2-0.7:3-6. The polyethylene glycol is added to introduce a polar group to enhance the water absorption of the polylactic acid, and the polylactic acid is modified in cooperation with the polylactic acid-hydroxyacetic acid copolymer, so that the obtained coated paper has the characteristics of high degradation efficiency and is beneficial to household composting.

The invention discloses a method for catalytically synthesizing aromatic-aliphatic copolyester by using a high-activity titanium catalyst, which comprises the following steps: (1) carrying out first-step esterification reaction on terephthalic acid and 1, 3-propylene glycol in the presence of alpha-titanium glycolate according to a molar ratio of 1: (2.5-7.5); (2) alpha-titanium glycolate is continuously added, adipic acid is added into the reaction mixture obtained in the step (1) in the presence of the alpha-titanium glycolate, a second-step esterification reaction is carried out, and the molar ratio of the adipic acid to the terephthalic acid is 1: (0.25-1.5); and (3) continuously carrying out ester exchange polymerization reaction on the reaction mixture obtained in the step (2) in the presence of alpha-titanium glycolate to obtain the aromatic-aliphatic copolyester. The aliphatic-aromatic polyester obtained by the method has excellent thermal properties, the efficiency of the used catalyst is high, and no toxic by-product is generated.

The application discloses a lactic acid-glycolic acid copolymer with adjustable end carbon chain length and a preparation method and application thereof. 20 The lactic acid-glycolic acid copolymer with adjustable end carbon chain length is alcohol-terminated lactic acid-glycolic acid copolymer, and a structural formula is as shown in the following formula: wherein R is selected from C1-C The alcohol-terminated lactic acid-glycolic acid copolymer provided by the application can change the degradation speed of the polymer by controlling the carbon chain length of the end group, can be used as a carrier of a sustained-release drug delivery system of various drugs, can meet the requirement of different sustained-release time, and has a wide application range.