55 results about "Methyl vinyl ether" patented technology

The invention discloses a high-temperature-resistant perfluoroether elastomer composition and a preparation method thereof. The preparation method of the high-temperature-resistant perfluoroether elastomer composition comprises the following steps: S1, carrying out emulsion polymerization on tetrafluoroethylene, perfluoromethyl vinyl ether, a non-conjugated fluorine diene vulcanization point monomer, a phenyl-containing perfluorodiene vulcanization point monomer and a peroxide initiator according to a preset proportion to obtain a perfluoroether elastomer emulsion; s2, condensing, washing and drying the perfluoroether elastomer emulsion to obtain perfluoroether elastomer micro powder; s3, mixing and thin-passing the perfluoroether elastomer micro powder with a filler, an acid acceptor and a vulcanizing agent in a preset proportion to obtain perfluoroether elastomer mixed rubber; and S4, carrying out compression molding on the perfluoroether elastomer rubber compound, and carrying out secondary vulcanization to obtain the perfluoroether elastomer composition with high temperature resistance and water vapor resistance. The perfluoroether elastomer composition prepared by the invention has the characteristics of high temperature resistance, water vapor resistance and low compression set.

The invention provides perfluorosulfonic acid resin and a polymerization method. The polymerization method comprises the following steps: mixing perfluoromethyl vinyl ether, perfluorosulfonyl fluoride vinyl ether and a fluorine-containing solvent to obtain a mixed solution; and adding an initiator into the mixed solution, introducing a tetrafluoroethylene monomer, carrying out a copolymerization reaction, carrying out solid-liquid separation, and carrying out transformation and drying to obtain the perfluorinated sulfonic acid resin. The perfluoromethyl vinyl ether monomer is introduced into a copolymerization system, so that the rigidity of a polymer main chain is effectively reduced, and the flexibility and low-temperature mechanical strength of the resin are enhanced; the crystallinity is effectively reduced, the Tg is adjusted, and the catalyst is suitable for low-temperature proton exchange membrane fuel cells and other application scenes; the introduction of perfluoromethyl vinyl ether improves the compatibility between the main chain and the sulfonyl fluoride-containing side chain, and is beneficial to the formation of a clearer and more continuous hydrophilic / hydrophobic microphase separation structure. A stable proton conduction network is facilitated, and the electrochemical performance of the resin under harsh working conditions is remarkably improved.

The present invention relates to the field of oral care and discloses a multi-effect synergistic oral whitening composition and its use. The oral whitening composition comprises: 3-80% methyl vinyl ether / maleic anhydride copolymer, 3-70% sodium monofluorophosphate, and 10-95% phosphate. The mass ratio of the methyl vinyl ether / maleic anhydride copolymer, sodium monofluorophosphate, and phosphate is 1:(0.2-7.5):(0.2-40). The molar ratio of methyl vinyl ether to maleic anhydride in the methyl vinyl ether / maleic anhydride copolymer ranges from 2:1 to 1:2, and the molecular weight ranges from 800,000 to 3,000,000. The present invention combines the methyl vinyl ether / maleic anhydride copolymer, sodium monofluorophosphate, and phosphate in specific proportions and types to produce a multi-effect synergistic effect in terms of rapid whitening, long-lasting prevention of tooth staining, and prevention of dental calculus.

The application belongs to the technical field of sodium ion batteries, and particularly relates to a binder composition, a sodium ion battery positive electrode slurry and a sodium ion battery. The binder composition comprises 0.5-100% and 0-99.5% of a first binder and a second binder by mass percentage, the first binder is one or more of polyacrylic acid, polymethacrylic acid, poly-methyl-vinyl-ether-copoly-maleic acid, and the second binder is one or more of polyvinylidene fluoride, polyacrylonitrile-based binder, polyurethane-based binder and polyimide-based binder. A high-molecular polymer containing a carboxyl group (-COOH) is used as a binder composition component to prepare the sodium ion battery positive electrode slurry. The carboxyl group can be neutralized with alkaline substances in the positive active material of the sodium ion battery positive electrode slurry, so as to ensure the uniformity and fluidity of the positive electrode slurry, to obtain a uniform sodium ion battery positive electrode sheet, and to obtain a sodium ion battery with good electrochemical stability.

The invention relates to the technical field of oral care materials, and particularly discloses macromolecular hydrogel-based false tooth safety paste and a preparation method thereof. The macromolecular hydrogel-based denture safety paste is prepared from the following components in parts by weight: 10 to 20 parts of white oil, 20 to 40 parts of vaseline, 40 to 60 parts of polydopamine modified polyvinyl alcohol-based hydrogel, 20 to 40 parts of sodium carboxymethyl cellulose, 20 to 40 parts of methyl vinyl ether-maleic anhydride copolymer calcium sodium salt, 0.1 to 1 part of silicon dioxide, 0.1 to 1 part of 93 to 98 percent ethanol, 0.05 to 1 part of preservative, 0.1 to 2 parts of essence and 0.001 to 0.01 part of pigment. The polydopamine modified polyvinyl alcohol-based hydrogel is prepared from polyvinyl alcohol, dopamine hydrochloride, an activating agent, a coupling agent and poloxamer. According to the technical scheme provided by the invention, the prepared false tooth fixing paste has excellent properties of good bonding effect and strong durability.

A method to manufacture a test strip for measuring specific gravity of a urine sample, the method including successively providing a polyelectrolyte in a first solution, the polyelectrolyte being poly(methyl vinyl ether-alt-maleic anhydride), adding to the first solution a base to neutralize the polyelectrolyte and to bring the first solution at a pH between 10 and 11, adding to the first solution a buffering agent to bring and maintain the first solution at a pH between 7.0 and 7.5, dipping a paper strip into the first solution, and dipping the paper strip into a second solution comprising a pH sensitive color indicator.

The application discloses a kind of high-temperature-resistant perfluoroether elastomer composition and preparation method, and the preparation method of high-temperature-resistant perfluoroether elastomer composition includes the following steps: S1, predetermined proportion of tetrafluoroethylene, perfluoromethyl vinyl ether, non-conjugated fluorine diene sulfur point monomer and phenyl-containing perfluorodiene sulfur point monomer and peroxide initiator emulsion polymerization obtain perfluoroether elastomer emulsion;S2, perfluoroether elastomer emulsion is condensed, washed, dried, and perfluoroether elastomer micro powder is obtained;S3, perfluoroether elastomer micro powder is mixed with predetermined proportion of filler, acid absorbent, vulcanizing agent and thin passage, and perfluoroether elastomer mixing rubber is obtained;S4, perfluoroether elastomer mixing rubber is molded by mould pressing, and secondary vulcanization obtains high-temperature-resistant, water-vapor-resistant perfluoroether elastomer composition.The perfluoroether elastomer composition prepared by the application has the characteristics of high-temperature resistance, water-vapor resistance and low compression permanent deformation.

The invention discloses a method for polymerizing a perfluoroether elastomer in supercritical carbon dioxide, the perfluoroether elastomer prepared by the method and a composition, the method comprises the following steps: adding carbon dioxide, a perfluoromethyl vinyl ether monomer and a tetrafluoroethylene monomer into a reactor, the carbon dioxide concentration in the reactor being greater than or equal to 30 mol%; and continuously adding the initiator, the chain transfer agent and the vulcanization point monomer to initiate the polymerization reaction of the perfluoroether elastomer. The reactor adopts a jacketed heat exchanger, combines spraying of a liquid tetrafluoroethylene monomer and perfluoromethyl vinyl ether and carbon dioxide reflux to supplement cold energy, utilizes latent heat of vaporization to absorb heat released by polymerization reaction, and controls the reaction temperature to be 35-125 DEG C. The perfluoroether elastomer prepared by the method has good thermal stability, and is suitable for industrial production. The preparation method has the advantages of simple process, chemical corrosion resistance and low fluorine ion extraction degree, and the temperature in the preparation process is accurately controlled, so that unstable end groups of the obtained perfluoroether elastomer are greatly reduced, and various physical properties of the elastomer are favorably improved.

The application relates to the field of polishing processing materials for metal pieces, and particularly discloses a fluid material for polishing metal pieces and a preparation method thereof. The fluid material for polishing metal pieces is prepared from the following raw materials in parts by weight: 20-30 parts of hydroxyl-terminated polydimethylsiloxane, 42-50 parts of abrasive, 18-28 parts of ethanol, 5-8 parts of a lubricating stabilizer, and 2-4 parts of a methyl vinyl ether / maleic anhydride copolymer. The preparation method comprises the following steps: the lubricating stabilizer and the methyl vinyl ether / maleic anhydride copolymer are added into the ethanol and stirred and dispersed, the hydroxyl-terminated polydimethylsiloxane and the abrasive are added and heated and kneaded and dispersed, and vacuum defoaming is performed. The fluid material prepared by the application is applied to polishing of metal pieces, has good temperature resistance and viscosity stability during the polishing process, the polished metal piece surface has good uniformity, the problem that the fluid material is prone to local non-uniformity or scratches during the polishing process is solved, and the polishing efficiency is improved.

The invention provides a fluororubber sealing element applied to a high-temperature dynamic sealing environment and a preparation method of the fluororubber sealing element, and relates to the field of fluororubber preparation. A vinylidene fluoride / tetrafluoroethylene / perfluoromethyl vinyl ether ternary fluoroelastomer is used as a main body material, carbon black is added, and PFA micro powder activated by a plasma etching machine is used as filler; oxygen-containing groups can be introduced after plasma treatment, the interface bonding effect of the PFA and the fluororubber can be improved, meanwhile, the surface energy of the activated PFA can be closer to that of the fluororubber, a nanoscale rough structure can be generated on the surface of the PFA due to etching, the material bonding strength is improved, the sealing performance and the thermal durability are improved, and the layering risk at the high temperature can be inhibited through strong interface bonding; according to the invention, perfluoropolyether oil (PFPE) is added, and 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane (bis (penta)), octadecylamine, zinc oxide and a graphene derivative are matched, so that the high-temperature-resistant hot-tear-resistant sealing element is prepared.

The invention relates to the technical field, and discloses a preparation process of a perfluoroether elastomer, which comprises the perfluoroether elastomer. The perfluoroether elastomer is prepared through ternary polymerization of 1, 1-difluoroethylene (VDF), perfluoromethyl vinyl ether (PMVE) and 3-hydroxy-2-trifluoromethyl propionic acid (MAF-OH), a self-made hydroxyl-containing third monomer MAF-OH is introduced, a polar group is successfully introduced into a fluoroelastomer molecular chain, and the polarity and compatibility of a polymer are effectively improved; the prepared perfluoroether elastomer is white powder, has excellent elasticity, high temperature resistance and chemical medium resistance, and has wide application prospects in the fields of preparation of high-end sealing materials, gaskets, rubber tubes and the like.

The application discloses rigid polyurethane foam, a preparation method and a refrigeration appliance, comprising: a combined polyether; isocyanate; foaming agent I, the foaming agent I is one of cyclopentane and isopentane or a mixture composed of cyclopentane and isopentane in any proportion; foaming agent II, the foaming agent II is one of pentafluoropropane and trifluoro-chloro-propylene or a mixture composed of pentafluoropropane and trifluoro-chloro-propylene in any proportion; and foaming agent III, the foaming agent III adopts perfluoromethyl vinyl ether. By adding perfluoromethyl vinyl ether as a foaming agent, the application overcomes the foam cavity problem of a low-boiling-point foaming system, reduces the foam molding density, improves the supporting capacity of low-density rigid polyurethane foam, and has low cost and high practicability.

The application belongs to the technical field of sodium ion battery materials, and particularly relates to a sodium ion battery water-based binder and a positive electrode slurry thereof. Poly[(methyl vinyl ether)-(maleic acid)] is hydrolyzed in a sodium hydroxide solution, and poly[(methyl vinyl ether)-(sodium maleate)] is obtained after vacuum drying, which is used as a water-based binder for a sodium ion battery positive electrode. The water-based binder has both high-polarity groups and low-polarity groups, thus solving the problem of easy settlement of conductive carbon in the water-based binder, ensuring high adhesion between components, and enhancing the volume expansion relief and repair capacity of the water-based binder during the charging and discharging process of the positive electrode sheet compared with PVDF and other binders. In general, the water-based binder has strong adhesion, repair force and interface adaptability, is environment-friendly and low in cost, and can make P2-Na x The MO2 positive electrode material has good energy density and stable cycle characteristics when used in a sodium ion battery.

According to the preparation method of the chlorogenic acid-methotrexate soluble microneedle, chondroitin sulfate and a methyl vinyl ether-maleic anhydride copolymer are adopted as matrix materials, and the drug-loaded microneedle is prepared through a two-step centrifugation method. The length of a needle body of the prepared microneedle is about 500 microns, the microneedle has good mechanical strength and skin puncture performance, the microneedle can be basically dissolved within 2 hours, the average drug content of chlorogenic acid is 57.97 + / -1.76 mu g / tablet, and the average drug content of methotrexate is 56.32 + / -1.67 mu g / tablet. An in-vitro percutaneous penetration test shows that the 6-hour cumulative transdermal rate of chlorogenic acid reaches 93.96%, the 6-hour cumulative transdermal rate of methotrexate reaches 86.92%, which are respectively 22.1 times and 3.0 times that of a control solution group, so that the efficient percutaneous delivery of the medicine is realized. The microneedle is small in skin irritation, the skin barrier can be naturally repaired within 15 minutes after puncture, and a new administration approach is provided for treatment of skin diseases such as psoriasis.

The application provides a preparation method of hydrophobic modified perfluoro ether elastomer, and applies to the technical field of perfluoro ether elastomer, and comprises the following steps: S1, mixing fluorine-containing vinyl cross-linkable fluorocarbon surfactant and ethylene glycol monomethyl ether, and stirring to obtain a composite dispersed microemulsion; S2, adding deionized water and vulcanization point monomer to the composite dispersed microemulsion, and stirring to form an emulsion; S3, adding perfluoromethyl vinyl ether and an initiator, and introducing tetrafluoroethylene gas to perform polymerization reaction, so as to obtain a perfluoro ether elastomer emulsion; S4, performing demulsification treatment, washing after acidification by concentrated sulfuric acid, and performing hydrophobic modification, so as to obtain hydrophobic modified perfluoro ether elastomer micro powder; and S5, mixing, mold pressing and secondary vulcanization are sequentially performed on the hydrophobic modified perfluoro ether elastomer micro powder, so as to obtain a hydrophobic modified perfluoro ether elastomer sealing product. According to the application, the perfluoro ether elastomer with low viscosity can be prepared, and the pollution of the fluorine-containing surfactant to the environment is reduced.

The invention discloses a method for industrially and continuously producing perfluoromethyl vinyl ether, which comprises the following steps: (1) introducing perfluoro-2-methoxypropionyl fluoride into a first fluidized bed filled with solid carbonate, reacting to obtain alkali metal intermediate salt, and cracking the alkali metal intermediate salt to obtain a perfluoromethyl vinyl ether product flow; (2) the perfluoromethyl vinyl ether product flow enters a separator, gas obtained through separation is compressed and rectified to obtain a perfluoromethyl vinyl ether product and carbon dioxide gas, and the carbon dioxide gas returns to the first fluidized bed to serve as carrier gas; discharging reacted and carbonized solid carbonate from the bottom of the first fluidized bed into a second fluidized bed; and (3) regenerating the reacted and carbonized solid carbonate in the second fluidized bed and then returning to the first fluidized bed. The method disclosed by the invention is an industrial continuous production process and has the advantages of simplicity in operation, high reaction yield, high product purity, high economical efficiency, environment friendliness and the like.

A tetrafluoroethylene-propylene copolymer with a solidification point monomer is mixed with a five-membered copolymer of vinylidene fluoride (VDF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), perfluorinated methyl vinyl ether (PMVE), and ethylene (PE), using a peroxide as an initiator and an aid TAIC as a crosslinking agent, and the resulting co-solidified fluoroelastomer shows improved curing performance, improved mechanical properties, and improved compression set. The co-solidified fluoroelastomer shows improved chemical resistance to solvent aging systems, and better retention of mechanical properties after high temperature aging in solvent systems.

The invention relates to the field of metal part polishing machining materials, and particularly discloses a fluid material for metal part polishing and a preparation method thereof. The invention relates to a fluid material for polishing a metal piece. The fluid material is prepared from the following raw materials in parts by weight: 20-30 parts of hydroxyl-terminated polydimethylsiloxane, 42-50 parts of an abrasive material, 18-28 parts of ethanol, 5-8 parts of a lubrication stabilizer and 2-4 parts of a methyl vinyl ether / maleic anhydride copolymer, the preparation method comprises the following steps: adding the lubrication stabilizer and the methyl vinyl ether / maleic anhydride copolymer into ethanol, stirring and dispersing, adding the hydroxyl-terminated polydimethylsiloxane and the grinding material, heating, kneading and dispersing, and carrying out vacuum defoaming. The fluid material prepared in the invention is applied to metal part polishing, the fluid material has good temperature resistance and viscosity stability in the polishing process, the surface uniformity of the polished metal part is good, the problem that local nonuniformity or scratches are easily generated in the polishing process of the fluid material is solved, and the polishing efficiency is improved.

The invention provides a preparation method of a hydrophobic modified perfluoroether elastomer, which is applied to the technical field of perfluoroether elastomers, and comprises the following steps: S1, mixing a fluorovinyl-containing crosslinkable fluorocarbon surfactant with ethylene glycol monomethyl ether, and stirring to obtain a composite dispersed microemulsion; s2, adding deionized water and a vulcanization point monomer into the composite dispersed microemulsion, and stirring to form an emulsion; s3, perfluoromethyl vinyl ether and an initiator are added, tetrafluoroethylene gas is introduced for a polymerization reaction, and perfluoroether elastomer emulsion is obtained; s4, demulsification treatment is carried out, washing is carried out after acidification with concentrated sulfuric acid, hydrophobic modification is carried out, and hydrophobic modified perfluoroether elastomer micro powder is obtained; and S5, sequentially carrying out mixing, compression molding and secondary vulcanization on the hydrophobic modified perfluoroether elastomer micro powder to obtain the hydrophobic modified perfluoroether elastomer sealing product. According to the process, the low-viscosity perfluoroether elastomer can be prepared, and the pollution of the fluorine-containing surfactant to the environment is reduced.

The present invention relates to phase change material (PCM) compositions comprising an aqueous solution of a salt hydrate phase change material component, one or more polymers, at least one of which is poly(4-styrenesulfonic acid-co-maleic acid), poly(methyl vinyl ether-alt-maleic acid), or polystyrenesulfonic acid, or mixtures of these polymers. The present invention also relates to methods of making PCM compositions comprising these polymers.

The invention relates to the technical field of steel and iron materials, in particular to a low-silicon low-sulfur cold-rolled steel sheet and a processing technology thereof. Steel raw materials are sequentially subjected to smelting, forging, hot rolling, acid pickling, cold rolling, critical annealing and leveling processes, and the steel plate is obtained. And then the copper-coated graphene powder and metal powder are used as raw materials, and the metal reinforced coating is prepared. The fluorine modified organic polysilazane is obtained by adding the organic polysilazane, the isocyanate terminated polyurethane, the tetrafluoroethylene, the hexafluoropropylene and the perfluoromethyl vinyl ether. And the fluorine modified organic polysilazane and amphiphilic nano silicon dioxide are used as raw materials to prepare the wear-resistant and corrosion-resistant coating. And sequentially depositing the metal reinforced coating and the wear-resistant and corrosion-resistant coating on the surface of the steel plate through a cold spraying process to obtain a finished product. The finished product prepared by the method has good surface strength, wear resistance and corrosion resistance, so that the finished product has a wide application prospect in the field of steel and iron materials.

The present application relates to a kind of polyamide composite and its preparation method and application, belong to the composition technical field of polymer compound.The polyamide composite of the present application includes the following weight parts of component: polyamide 94~99.7 parts, tackifier 0.2~4 parts, processing aid 0.1~2 parts;The tackifier includes methyl vinyl ether-maleic anhydride copolymer and polytetrafluoroethylene.The polyamide composite has good processing ductility, can make the product prepared have excellent uniformity.

The invention relates to the technical field of fluorine chemical industry, in particular to a preparation method of perfluoromethoxy methylene vinyl ether.The preparation method comprises the following steps that S1, perfluoroolefin serves as a raw material to be subjected to an ozone cracking reaction, and trifluoromethyl fluoroformate is obtained through separation and purification; s2) enabling the trifluoromethyl fluoroformate to react with fluorine gas and halogenated olefin to generate fluorine halogen ether; and S3) carrying out dehalogenation or hydrogen generation on the fluorine halide ether to obtain the perfluoromethoxy methylene vinyl ether. The technical scheme provided by the invention has the following advantages: 1) the raw material cost is low, the main raw material for preparing trifluoromethyl fluoroformate is fluorine-containing olefin, and industrialization is realized; the perfluoromethoxy methylene vinyl ether has the advantages of simple preparation process, mild process conditions, simplicity, safety, reliability, good reaction selectivity, easy product separation, high yield, low cost and suitableness for industrial scale-up production.

The invention relates to the field of functional composite materials, and discloses a preparation process of an ecological leather fiber velvet composite material and a product. The preparation process of the ecological leather fiber velvet composite material comprises the following steps: S1, needling sea-island fibers to prepare a non-woven fabric; s2, carrying out gum dipping treatment by using a polyurethane gum dipping solution, and drying; s3, decrement splitting, water washing and drying; s4, softening treatment and sanding; s5, soaking with a pretreatment solution, dyeing with a dyeing agent, and drying; the pretreatment liquid in the step S5 contains a dyeing auxiliary agent composed of polydimethyldiallylammonium chloride, a methyl vinyl ether-maleic anhydride copolymer and bis [3-(triethoxysilyl) propyl] amine, and the dyeing agent is an acid dye containing sulfonate. According to the preparation method, through the preparation process of firstly sanding and then dyeing, and optimizing the types of the pretreatment liquid and the dyeing agent, the prepared ecological leather fiber velvet composite material has relatively good dyeing uniformity, color fastness and soft comfort, and the problem of white exposure after abrasion does not occur.

The high-pressure reactor comprises a reaction kettle, the reaction kettle comprises a heat preservation barrel, an inner barrel is fixedly installed on the inner wall of the heat preservation barrel, a conical bottom barrel is connected to the bottom of the inner barrel in a welded mode, a sealing ring is connected to the top of the heat preservation barrel and the top of the inner barrel in a welded mode, and a locking ring is connected to the inner wall of the inner barrel in a welded mode. The inner wall of the locking ring is fixedly connected with a positioning ring through a first bolt, the inner wall of the positioning ring is fixedly connected with a top cover through a second bolt, the locking ring and a sealing ring are matched for use, the top cover is fixedly installed on the top of the heat preservation cylinder and the top of the inner cylinder in a fastened and sealed mode, and a feeding cylinder is fixedly installed on the top of the top cover in a matched mode; the two first valves which are distributed up and down are arranged at the bottom of the feeding cylinder, so that the interior of the inner cylinder can be kept sealed, the situation of pressure relief of the inner cylinder can be effectively avoided, the use practicability of the equipment is improved, and raw materials can be conveniently added in the preparation reaction process.

An inkjet ink composition comprising: 1 to 15% by weight, based on the total weight of the inkjet ink composition, of at least one pigment, a carrier fluid, and 0.1 to 25% by weight, based on the total weight of the inkjet ink composition, of at least one polymer comprising first monomers selected from ethylenically unsaturated, hydrophobic monomers, wherein the ethylenically unsaturated, hydrophobic monomers are selected from styrene, α-methylstyrene, ethylene, propylene, 1-butylene, isobutylene, butadiene, methyl vinyl ether, and ethylenically unsaturated esters. and second monomers selected from maleic anhydride, maleic acid and salts, esters, imides and amides thereof, wherein at least a portion of the second monomers is functionalized with at least one organic group having a calcium index value greater than the calcium index value of phenylphosphonic acid, and wherein the first monomers are provided in the at least one polymer in a proportion in the range of 40 to 90 mol% relative to the at least one polymer, and wherein the second monomers are provided in the at least one polymer in a proportion in the range of 10 to 60 mol% relative to the at least one polymer, and wherein the at least one polymer has an acid number of 90 to 325 according to the following equation: AN (xlink) = AN (SP) − (% CO 2 − Target) × AN (SP) where “AN(xlink)” represents the acid number of the at least one polymer being crosslinked, “AN(SP)” represents the acid number of the starting polymer, and “%CO2 target” represents the percentage of the carboxylate-containing target for crosslinking.

The present disclosure relates to a method of manufacturing a test strip for measuring the specific gravity of a urine sample, the method comprising successively: - providing a polyelectrolyte in a first solution, the polyelectrolyte being a poly(methyl vinyl ether-alt-maleic anhydride), - adding to the first solution a base to neutralize the polyelectrolyte and bring the first solution to a pH between 10 and 11, - adding to the first solution a buffering agent to bring and maintain the first solution at a pH between 7.0 and 7.5, - dipping a paper strip into the first solution, - dipping the paper strip into a second solution comprising a pH-sensitive colored indicator. Figure 9

The invention belongs to the technical field of fluorine-containing modified monomer preparation, and particularly relates to a preparation method and a preparation device of perfluoromethyl vinyl ether. The preparation method comprises the following steps: (1) adding a catalyst and a solvent into a reaction kettle, and uniformly stirring to obtain a catalyst solution; introducing carbonyl fluoride gas into the catalyst solution, and then dropwise adding hexafluoropropylene oxide liquid into the catalyst solution in a liquid phase to carry out an addition reaction, so as to obtain an intermediate product perfluoro-2-methoxypropionyl fluoride; wherein the catalyst comprises potassium fluoride and cesium fluoride, and the mass ratio of the potassium fluoride to the cesium fluoride is (10-20): 1; (2) dropwise adding a liquid phase of the intermediate product perfluoro-2-methoxypropionyl fluoride into a mixed solution of carbonate and a solvent, and carrying out a salt-forming cracking reaction to obtain a crude product of perfluoromethyl vinyl ether; according to the preparation method and the preparation device, the yield of the perfluoromethyl vinyl ether can reach 90% or above, and the preparation method and the preparation device are suitable for industrial production.

An oral care composition is disclosed, comprising 0.01 to 10% by weight of a deposited polymer and a polyhydroxy fatty acid amide surfactant of formula (I); wherein R 1 It is a C1-C4 alkyl or hydroxyl-substituted C1-C4 alkyl; R 2 It is a straight-chain or branched, saturated or unsaturated hydrocarbon chain having 15 to 21 carbon atoms, and a beneficial agent selected from optical agents, antimicrobial agents and mixtures thereof; wherein the deposited polymers include xanthan gum, sodium alginate, pectin, modified starch, gelatin, carrageenan, gellan gum, fenugreek gum, konjac gum, tragacanth gum, arabic gum, γ-polyglutamic acid, sodium heparin, copolymers of methyl vinyl ether and maleic anhydride, polyacrylic acid, polystyrene sulfonate, deoxyribonucleic acid, poly(allylamine), locust bean gum, guar gum, polyglycolic acid, polylactic acid, poly(glycolic acid-co-lactic acid), chitosan, humic acid, phytic acid, derivatives thereof or mixtures thereof:

The invention discloses an IR783 soluble microneedle patch as well as a preparation method and application thereof, according to the method, chondroitin sulfate and a methyl vinyl ether-maleic anhydride copolymer are adopted as matrix materials, and a drug-loaded microneedle is prepared through a two-step pouring method. The length of the prepared microneedle body is about 500 microns, the diameter of the base is about 281 microns, and the microneedle has good mechanical strength and skin puncture performance and can be completely dissolved within 2 hours. The average drug loading capacity of IR783 is increased along with increase of the preparation concentration, and when the preparation concentration is 4 mg / mL, the average drug loading capacity reaches 28.51 + / -0.8013 microgram / tablet. An in-vitro release rate test shows that the release rate of IR783 within 15 minutes reaches 88.39%. A photo-thermal property investigation result shows that under the irradiation of 808nm laser, the photo-thermal temperature of IR783-DMNs can reach 56.77 DEG C to the maximum within 120 seconds, and exceeds a 42 DEG C threshold value required by photo-thermal therapy. The microneedle is non-irritant to the skin, the skin can be naturally healed within 15 minutes after puncture, and a new administration mode is provided for photothermal therapy of skin cancer.