1228 results about "N-Methyl-2-pyrrolidone" patented technology

An electro-optic assembly comprises an adhesive layer and a layer of electro-optic material. The adhesive layer comprises a polymeric adhesive material and an ionic material having either its cation or its anion fixed to the polymeric adhesive material. The ionic material reduces the volume resistivity of the polymeric adhesive material and is not removed upon heating to 50° C. In a similar electro-optic assembly comprising an adhesive layer and a layer of electro-optic material, the adhesive layer comprises a polymeric adhesive material which has been subjected to dialysis or diafiltration to remove organic species having a molecular weight less than about 3,500, so that the adhesive material has a content of N-methylpyrrolidone not exceeding 500 ppm based upon the total weight of the adhesive layer and layer of electro-optic material.

A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the pressure and temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone. The method and apparatus produces purified terephthalic acid having a purity desired for use in forming polyester resin and other products at an economically attractive rate and at operating conditions of reduced severity which require a lower capital investment and simplified processing.

The invnetion provides a preparation method for a graphene oxide/polyvinylidene fluoride composite ultrafiltration membrane and relates to the preparation method of the graphene oxide/polyvinylidene fluoride composite ultrafiltration membrane. The invention aims to solve the problem of poor hydrophilicity and stain resistance of the existing polyvinylidene fluoride ultrafiltration membrane. The method provided by the invention comprises the following steps of: 1. respectively adding graphene oxide, polyvinylpyrrolidone and polyvinylidene fluoride with N-methylpyrrolidone as solvent, heating and stirring to obtain casting membrane solution; 2. putting the casting membrane solution on a clean glass plate and scrapping to a certain thickness by a coating device, and then immersing distilled water, shedding and drying to obtain the graphene oxide/polyvinylidene fluoride composite ultrafiltration membrane. The preparation method provided by the invention can be applied to the fields of drinking water preparation, food industry, pharmaceutical industry, biotechnology, chemical process and environmental engineering.

The invention relates to a method for modifying aramid fiber by using carbon nano tubes, which comprises the following steps of: selecting an epoxy resin/ aramid fiber composite material as a research object, selecting the carbon nano tubes as a surface modification material, forming free amino groups in a certain ratio on the aramid fiber by a chemical modification method, soaking the aramid fiber into N-methylpyrrolidone solution (NMP), and reacting the solution and the surface carboxylation carbon nano tubes with the aid of ultrasonic, wherein part of carbon nano tubes enter the interior of Kevlar fiber, and the other part of carbon nano tubes are fixed on the surface of the fiber through amido bonds formed by the carbon nano tubes and amino, thus, a aramid fiber complex inside and outside which the carbon nano tubes are doped is formed. Single fiber tensile test results and single fiber pull-out test results show that the mechanical property of the modified aramid fiber and the interface bonding strength with the epoxy resin are improved.

The invention discloses a high-performance flat-type cellulose acetate/graphene blend forward osmosis membrane. 5 to 25 percent by weight of cellulose acetate, 1 to 15 percent by weight of additives, 0.01 to 2 percent by weight of graphene and mixed solvent of dimethylformamide, dimethylacetamide, or N-methylpyrrolidone and acetone are added into a dissolving tank according to a given sequence and are stirred and dissolved for 2 to 18 hours at the temperature of 5 to 75 DEG C to be uniformly mixed so as to prepare a forward osmosis membrane casting solution; the high-performance flat-type cellulose acetate/graphene blend forward osmosis membrane is prepared on a supporting material by adopting a phase inversion method. According to the forward osmosis membrane, 1M NaCl is used as a driving liquid, the deionized water is used as a raw material solution, the flux of pure water of the forward osmosis membrane is more than 21L/m<2> within the test time of one hour, and the salt flux in the reverse direction is less than 3.5g/m<2>.

The invention discloses a method for preparing poly(arylene ether nitrile) resin powder, and belongs to the technical field of high polymer materials. 2,6-dichlorobenzonitrile and aromatic dihydric phenol are taken as raw materials, 1-methyl-2-Pyrrolidinone is taken as a solvent, anhydrous potassium carbonate or anhydrous sodium carbonate is taken as a catalyst, and methylbenzene or dimethylbenzene is taken as a dehydrating agent; and the method comprises the following steps of: performing reflux reaction at the temperature of between 130 and 160 DEG C for 2 to 4 hours in a reactor, slowly evaporating out water and the dehydrating agent, and raising the temperature to 180-200 DEG C until a macromolecular rod-climbing phenomenon happens; adding the solvent into the reactor, and diluting the reaction products to the mass concentration of 2 to 15 percent; and adding a precipitator into the reactor, continuously stirring, performing centrifugal solid-liquid separation, washing the solid in acidic boiling water, filtering and drying to obtain the poly(arylene ether nitrile) resin powder. The prepared poly(arylene ether nitrile) resin powder has the characteristics of superfine granularity (reaching 100-400 meshes), uniform granularity, high purity, stable performance, and excellent electrical property, and can be widely applied in the fields such as electronics, precision machines, aerospace, new energy and the like.

The invention discloses a porous nano carbon fiber material, a lithium battery elemental sulfur/porous nano carbon fiber composite anode material and an anode plate which are prepared from the porous nano carbon fiber material. The lithium battery elemental sulfur/porous nano carbon fiber composite anode plate is prepared by using the method: (1) mixing lithium battery elemental sulfur/porous nano carbon fiber composite anode material shown by the right requirements 3 with acetylene black and an adhesive and uniformly stirring to obtain a mixture; and (2) adding an N-methyl pyrrolidone solution to the mixture obtained in the step (1), proportioning into paste and scraping the paste on a carbon-coated aluminum foil as a current collector and drying to obtain an elemental sulfur/porous nano carbon fiber composite anode plate. Lithium sulphur batteries made by utilizing the anode plate of the invention have greatly-improved cycle performance.

A process for recovering a base oil of lubricating viscosity from used oil in which, following optional pretreatment, used oil is re-refined by distilling it in distillation apparatus having multiple theoretical plates. Impurities are then extracted from the lube range distillate fraction or fractions with a liquid extractant such as N-Methyl-2-Pyrrolidone (NMP) at a temperature below the temperature, if any, of complete miscibility of the extractant and the oil. The oil and extractant are then separated whereupon the extractant is re-used in the process and the oil is subject to further treatment, as necessary, for targeted uses.

The invention relates to a graphene/conductive polymer composite film and a preparation method thereof. The graphene/conductive polymer composite film comprises products prepared by the following reaction: 1) preparing graphite oxide from graphite by a chemical oxidation method; 2) adding an oxidant ammonium persulfate into monomer containing acid solution to prepare conductive polymer; 3) performing ultrasonic dispersion on the graphite oxide and the conductive polymer in N-methylpyrrolidone, adding a reducing agent, and stirring; 4) coating solution prepared by step 3) on the surface of a substrate to form a film, washing and drying; and 5) repeating the step 4) until the film has the required thickness. The graphene/conductive polymer composite film and the preparation method have the advantages that: 1) the formed graphene/conductive polymer composite film has good electric conduction and antistatic property, and has the conductivity between 1*10<-3> and 1*10<2>S/cm; 2) the conjugated structure of the grapheme and the conductive polymer ensures that the grapheme and the conductive polymer have high compatibility; 3) the composite film has controllable thickness; and 4) the preparation method has simple conditions and easy operation.

A pharmaceutical composition for external use, including: i) luliconazole represented by the following structural formula (1) and/or a salt thereof; and ii) one or two or more selected from N-methyl-2-pyrrolidone, propylene carbonate, and crotamiton.

The invention relates to a blocking remover of a gas well shaft. The blocking remover comprises, by weight, 5-25% of an alcohol ether compound, 0.5-10% of a dispersant, 1-10% of a cleaning agent, and 0.5-5% of chelating agent, with the balance being a nitrogen-containing polar solvent, wherein the nitrogen-containing polar solvent is one selected from N,N dimethyl formamide, N,N dimethyl acetamide, and N-methyl pyrrolidone, the alcohol ether compound is one selected from glycol-ether, glycol-propyl ether, glycol-butyl ether, and diglycol-ether, the disperant whose micelle particle size is from 20nm to 100nm is a middle-phase microemulsion-type dispersant mixed by kerosene, water, a surfactant and a cosurfactant, the cleaning agent is one selected from allene diamine, acetonitrile and pentylamine, and the chelating agent is one selected from sodium citrate and EDTA. The blocking remover has the advantages that corrosivity is weak, that the speed of dissolving blockage is fast, that the product performance is stable in high temperatures, and that the blocking remover can reduce damages caused by water locking and fouling in areas close to gas wells, and can recover the permeability of storing layers.

The method includes following steps: cut off batteries; separate anode materials, and cut the anode material into pieces; the anode pieces are steeped into N-Methyl-2-Pyrrolidone liquor, and are heated to separate activating material LiCoO2, and then acquire black powder. The black powder is putted into nitric acid solution or spirit of salt, and after filtering the nitric acid solution or chloride solution containing Co2+,Li+ ion is acquired. NH3íñN2O is added into Co2+,Li+ ion acidic solution, and meanwhile add surfactant; LiOH is added into suspension to adjust concentration of Li+ in suspension; the suspension is filtered and dried, then is sintered at 600-900 Deg C. to acquire LixCoO2 powder.

The present disclosure generally relates to methods of preparing nicotine and resolving R,S nicotine to enrich the (S)(−) enantiomer. The method may comprise combining N-methyl-2-pyrrolidone or a salt thereof with a nicotinate compound in the presence of a solvent and a strong base to form 1-methyl-3-nicotinoyl-2-pyrrolidone or a salt thereof; and reducing the 1-methyl-3-nicotinoyl-2-pyrrolidone or salt thereof in solution with Na₂S₂O₄ to produce racemic nicotine or salt thereof. Resolving the racemic nicotine (or other enantiomeric mixture) may comprise combining the nicotine with (−)-O,O′-di-p-toluoyl-L-tartaric acid (L-PTTA).

This application relates to a composite solvent for separating aromatics by extractive distillation, comprising a main solvent, a solutizer and a modifier. Said solutizer is selected from any one or mixtures of any two of C₈–C₁₁ aromatics having different number of carbon atoms, the content of which is 3–39 wt %, and the number of carbon atoms of the lowest aromatic in the solutizer should be greater than that of the highest aromatic in the aromatics to be separated. When the solutizer is selected from any one of C₈–C₁₁ aromatics, the composite solvent contains 0.01–10.0 wt % of the modifier; when the solutizer is selected from mixtures of any two of C₈–C₁₁ aromatics having different number of carbon atoms, the composite solvent contains 0–10.0 wt % of the modifier. Said main solvent and modifier are independently selected from sulfolane derivatives, N-formyl morpholine, and N-methyl pyrrolidone, provided that the acidity and basicity of the modifier are opposite to those of the main solvent. When the composite solvent is used to recover aromatics by extractive distillation, it is possible to moderate the operation conditions of solvent recovery, increase the yield of aromatics, and make the separated aromatics to be neutral.

The present invention discloses a positive electrode sheet of a lithium iron phosphate type lithium ion battery, and a preparation method thereof. According to the present invention, a positive active material coating comprise a nano-lithium iron phosphate positive active material coating a and a nano-lithium iron phosphate positive active material coating b; nano-lithium iron phosphate positive active material slurry a is coated on a current collector; nano-lithium iron phosphate positive active material slurry b is coated on the nano-lithium iron phosphate positive active material coating a; electrode lugs are spot welded on reserved blank of the current collector. The method comprises the following steps that: A, a lithium iron phosphate positive active material is respectively mixed with a nano carbon black conductive agent, a polyvinylidene difluoride agglomerant and a N-methylpyrrolidone solvent according to the ratio to prepare the nano-lithium iron phosphate positive active material slurry a and the nano-lithium iron phosphate positive active material slurry b; B, the slurry prepared from the lithium iron phosphate are coated on a side or both sides of the current collector having a certain thickness to form the coatings; C, the positive electrode sheet having coatings is prepared. The lithium iron phosphate type lithium ion battery has characteristics of high capacity, high rate, good effect. With the positive electrode sheet provided by the present invention, the service life of the lithium ion battery is prolonged.

A composition for intranasal delivery of a drug comprising: includes: (i) the drug; and (ii) a non-aqueous vehicle containing (a) propylene glycol and at least one additional solvent selected from N-methylpyrrolidone, propylene carbonate, dimethyl sulfoxide and at least one propylene glycol fatty acid ester; (b) from about 40 to 100% by volume of N-methylpyrrolidone; or (c) from about 40 to 100% by volume of dimethyl sulfoxide (DMSO).

The invention provides a preparation method for a three-dimensional carbon nanotube/nitrogen-doped graphene/sulfur electrode slice. The preparation method comprises the following steps of (1) adding the carbon nanotube, graphite oxide and polyacrylonitrile to N-methyl pyrrolidone, performing an ultrasonic reaction, coating an aluminium foil with mixed paste, and performing vacuum drying to obtain the electrode slice; (2) putting the obtained electrode slice into a muffle furnace under ammonia gas protection, heating to 400-500 DEG C, and naturally cooling; and (3) enabling the electrode slice obtained in the step (2) to be fully inserted into a Na2S2O3 solution, and slowly adding hydrochloric acid to the solution in a dropwise manner until the PH value of the solution reaches 6.5-7.5, taking out the electrode slice, and drying the electrode slice to obtain a positive plate. The electrode slice prepared by the invention can be directly used for the positive electrode of a lithium-sulfur battery without requiring a conductive agent and a binder, so that the cost of the electrode is greatly lowered.

The invention discloses a method for synthesizing low-color high-purity fiber-grade polyphenylene sulfide resin. According to the invention, sodium sulfide and p-dichlorobenzene are adopted as raw materials; N-methyl pyrrolidone, N,N-dimethyl acetamide, and the like are adopted as solvents; under the existence of a basic salt, through a four-step method comprising pre-polymerization, polymerization, chain extension and end-capping, the high-purity low-color fiber-grade polyphenylene sulfide resin is synthesized. By adjusting process parameters, polyphenylene sulfide average molecular weight and distribution index can be effectively controlled. Also, purification process can be simplified, and metal ion embedding can be reduced. Resin slice color is reduced, resin processing stability is improved, and resin performance is improved.

The invention relates to polyimide containing a benzimidazole unit and a preparation method thereof. The polyimide has the following structural formula. The preparation method comprises the following steps of: firstly, performing the reaction on 2,6-disubstituted aniline and aldehyde under the acidic condition to generate a diamine compound 3,3',5,5'-tetra-substituted aromatic diamine; and then, after mixing the synthesized aromatic diamine and a heterocyclic diamine monomer 6-aminophenyl-2-aminobenzimidazole according to a certain ratio, performing the reaction on the mixture and a dianhydride monomer in an organic solvent to obtain the polyimide. The polyimide provided by the invention has excellent solubility property, can be dissolved in conventional solvents such as NMP (N-methyl-2-pyrrolidone) and DMAc (dimethyl acetamide), has excellent heat resistance and mechanical property and has excellent thermal properties of glass-transition temperature of over 410 DEG C, decomposition temperature of over 500 DEG C and the like.