1734 results about "Dimethylacetamide" patented technology

PCT No. PCT/KR96/00250 Sec. 371 Date May 18, 1998 Sec. 102(e) Date May 18, 1998 PCT Filed Dec. 26, 1996 PCT Pub. No. WO97/24358 PCT Pub. Date Jul. 10, 1997The present invention relates to a novel crystalline cefdinir intermediate having formula (II) which can be used very usefully for preparing a cephalosporin antibiotics, cefdinir, in which Ph represents phenyl, p-TsOH represents p-toluenesulfonic acid, and DMAC represents N,N-dimethylacetamide, to a process for preparation thereof and to a process for preparing cefdinir using the compound of formula (II). According to the present invention, cefdinir can be prepared in an excellent color and purity and with a good yield.

The invention discloses polyvinylidene fluoride/graphene composite and a preparation method thereof. The preparation method includes: reducing oxidation graphene by reductant, mixing the reduced graphene and polyvinylidene fluoride with N, N-dimethylacetamide solvent to be solution, drying and hot-pressing the solution to obtain the polyvinylidene fluoride/graphene composite. The prepared polyvinylidene fluoride/graphene composite has the following advantages that 1) dielectric constant of the polyvinylidene fluoride/graphene composite is high and can reach 7940 on the condition of 100Hz frequency and the weight percentage of the graphene is 0.02; and 2) flexibility is fine. Meanwhile, the preparation method has the advantages of simple operation and high stripping and dispersing degree of graphene and the like.

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 preparation method of hydrogenated xylylene diisocynate. The preparation method of the hydrogenated xylylene diisocynate comprises the following steps: (1) performing salt forming reaction on 1,3-cyclohexanol dimethylamine and concentrated hydrochloric acid in a two-phase reaction solvent to obtain amine salt, wherein the two-phase reaction solvent consists of water and an inert organic solvent insoluble in water ; (2) performing photochemical reaction on the ammonium salt obtained in the step (1) and phosgene in an inert solvent by taking N,N-dimethylformamide or N,N-dimethylacetamide as a catalyst to obtain reaction liquid, and performing aftertreatment on the reaction liquid to obtain the hydrogenated xylylene diisocynate. The preparation method of the hydrogenated xylylene diisocynate has the advantages of complete ammonium salt formation, small grain size of the ammonium salt, low viscosity of the ammonium salt, high space-time conversion rate of photochemical reaction, simple process, low cost and the like.

The invention relates to a preparation method of a polybenzimidazole crosslinking membrane that is crosslinked with bihalohydrocarbon or polyhalohydrocarbon, which takes amino dibasic acid and aromatic tetraamine as monomer raw material and polyphosphoric acid as reaction medium and reaction is carried out for 5-30 hours at 150-220 DEG C under the nitrogen protection condition so as to obtain homopolymer containing amino polybenzimidazole, and takes the amino dibasic acid, nonaminonic dibasic acid and the aromatic tetraamine as the monomer raw materials to prepare copolymer containing amino polyphosphoric under the same conditions. The prepared homopolymer and the copolymer of the polybenzimidazole have good dissolvability in solvents of dimethyl sulphoxide, N, N-dimethylacetamide, phosphate, vitriol and methane-sulforic acid, etc. Both the structures of the homopolymer and the copolymer of the polybenzimidazole contain amino that can be used for crosslinking. The bihalohydrocarbon or the polyhalohydrocarbon is used as cross linking agent. The polybenzimidazole crosslinking membrane with good property can be prepared through crosslinking reaction of the amino contained in the polybenzimidazole and the bihalohydrocarbon or the polyhalohydrocarbon.

The present invention relates to an aligning agent for liquid crystal containing at least a polymer and solvent selected from polyamic acid and polyimide gained by dewatering closed-loop, the solvent contains: (A) a first solvent containing compound with formula (I); (B) a second solvent selected from at least one of N-methyl-2-pyrrolidone, gamma-butyrolactone, 1,3-dimethyl-2-imidazolone, N, N-dimethylformamide and N, N- dimethylacetylamide; and (C) a third solvent selected from at least one of butyl cellosolve, diacetone alcohol, carbonic sub-propyl ester, diethylene glycol diethyl aether and ethyl-3- oxethyl propionic ether. (In formula (I) the R respectively represents alkyl with 3 to 10 carbon atoms).

The invention discloses a synthesis method for terpolymer block silicone oil. The synthesis method is characterized by comprising the steps of: (A) adding 100 parts by weight of dimethyl cyclosiloxane or octamethyl cyclotetrasiloxane, 4 parts by weight of epoxy-terminated disiloxane and 15 parts by weight of dimethylacetamide, raising the temperature to 70-80 DEG C, adding 0.02-0.1 part by weight of base catalyst, raising the temperature to 110-120 DEG C, reacting for 3-4 hours, slowly opening vacuum, extracting solvents and low molecular weight matters, continuously raising the temperature to 140-145 DEG C, maintaining the temperature and the vacuum for 2 hours, so as to obtain epoxy silicone oil; and (B) adding 80-100 parts by weight of epoxy-terminated silicone oil, 6-30 parts by weight of polyether polyol and 150 parts by weight of isopropyl alcohol, carrying out backflow reaction for 6-15 hours at 80-86 DEG C, and decompressing and removing the isopropyl alcohol or adding a propylene glycol displacement solvent, so as to obtain amino polyether block silicone oil. By utilizing the terpolymer block silicone oil disclosed by the invention, the fabric has good hand feel, namely fluffy feel and smooth feel, cannot be yellowed or is slightly yellowed.

The invention relates to a method for preparing a polybenzimidazole crosslinking membrane by using epoxy compounds, which takes amino dibasic acid and aromatic tetraamine as monomer raw material and polyphosphoric acid as reaction medium and reaction is carried out for 5-30 hours at 150-220 DEG C under the nitrogen protection condition so as to obtain homopolymer containing amino polybenzimidazole, and takes the amino dibasic acid, nonaminonic dibasic acid and the aromatic tetraamine as the monomer raw materials to prepare copolymer containing amino polyphosphoric under the same conditions. The prepared homopolymer and the copolymer of the polybenzimidazole have good dissolvability in solvents of dimethyl sulphoxide, N, N- dimethylacetamide, phosphate, vitriol and methane-sulforic acid, etc. The bifunctionality or polyfunctional epoxy compounds are used as cross linking agent. The polybenzimidazole crosslinking membrane that has good property can be prepared through crosslinking reaction of the amido contained in the polybenzimidazole and epoxy functional groups contained in the bifunctionality or polyfunctional epoxy compounds.

The present invention provides a composition including an association complex of a pharmaceutical composition and one or more polyethylene-polypropylene glycol block co-polymers (poloxamers). The pharmaceutical composition may include a member selected from the group consisting of (a) an association complex of an eprosartan composition including eprosartan or a pharmaceutically acceptable salt of eprosartan and (b) the non-zwitterionic compound 2-(7-chloro-5-methyl-4-oxo-3-phenyl-4,5 dihydro-3H-pyridazino (4,5-b)indol-1-yl)-N,N-dimethylacetamide (NZ).

The invention discloses a graphene modified polyimide-based composite which is characterized in that the graphene modified polyimide-based composite comprises the following components in parts by weight: 95-105 parts of 4,4'-diaminodiphenyl ether, 110-120 parts of pyromellitic dianhydride and 1-25 parts of graphene. A preparation method comprises the steps of weighing ODA (octyl decyl adipate) and the graphene in proportion, measuring a DMAC (dimethylacetamide) solvent, adding the ODA, the graphene and the DMAC solvent to a reaction vessel, using ultrasonic till the ODA is dissolved sufficiently and the graphene is dispersed completely in the DMAC to obtain a graphene suspension, adding PMDA (pyromellitic dianhydride) in batches under high-speed stirring conditions till weak pole climbing appears, continuing to stir to allow diamine to react with dianhydride completely, and flattening an obtained graphene/PAA (poly acrylic acid) complex to obtain a composite film with uniform thickness so as to obtain a graphene polyimide composite film. The composite is 0.5 g/cm<3>-1.5 g/cm<3> in density and 60-170 KJ/m<2> in tensile strength.

The invention relates to a cellulose-polyacrylonitrile composite fiber and a manufacturing method of the same, the inventive method is characterized in that the composite fiber is a bending type or sheath-core type, the mass ratio of cellulose and polyacrylonitrile is 1:99 to 80:20 in the cortex of bending type or sheath-core type, the core layer of sheath-core type is made of the cellulose or polyacrylonitrile; the manufacturing method is that a ionic liquid is a solvent, also the organic solvent is a cosolvent, the organic solvent includes one or more N-N-dimethylacetamide, N-N-dimethylformamide or dimethyl sulfoxide. The bending type or sheath-core type composite fiber is formed after deairing, filtering, spinning, freezing, drawing, washing, drying and other steps, the fiber has a microporous structure which endows the characteristic of moisture absorption, breathable, coloring, good health, and other because of the moisture absorption of cellulose and the semi-compatibility of polyacrylonitrile; the ionic liquid is used in the production process being more green environmental protection.

A catalytic system for cellulose acylation includes an adduct of sulfuric acid with N,N-dimethylacetamide, free sulfuric acid or free N,N-dimethylacetamide with the following mole ratio of the components: adduct:1.0; free sulfuric acid, max:0.49; or free N,N-dimethylacetamide, max:0.4. A process for producing such a catalytic system is based upon reacting sulfuric acid with N,N-dimethylacetamide in an anhydrous medium at a temperature of 0° C.-25° C. with the following mole weight ratio of the components: sulfuric acid:1.0; N,N-dimethylacetamide, max:1.4. A process for cellulose acylation in the presence of this catalytic system incorporates cellulose treatment with acetic acid followed by treatment of the resultant activated cellulose with a lower fatty acid anhydride at a temperature of 10° C.-90° C. in the presence of this catalytic system taken in an amount of 1.5-30.0 wt. % of the cellulose weight in terms of sulfuric acid, a weight ratio of the liquid phase and cellulose being 3-7:1, respectively.

This invention is a novel pharmaceutical formulation of aqueous EDTA (Ethylene diamine tetraacetic acid) free solution of meloxicam in combination with meglumin for administration by oral or parenteral route, comprising one or more pharmaceutically acceptable excipients which is comprising N,N dimethylacetamide and propylene glycol for treating mammals, preferably animals.

The invention discloses a super hydrophobic modification method for polyvinylidene fluoride hydrophobic membranes and belongs to the technical field of membrane separation. The method comprises: preparing membrane casting solution by using polyvinylidene fluoride (PVDF), N,N-dimethylacetamide (DMAC) serving as a solvent and non-solvent low-molecular-weight alcohol and aging the membrane casting solution to form upper membrane solution; preparing membrane casting solution by using PVDF, DMAC, LiCl or/and polyvinyl pyrrolidone (PVP), and aging the membrane casting solution to form lower membrane solution, wherein the PVDF content in the lower membrane solution is higher than that in the upper membrane solution; scraping the lower membrane solution and the upper membrane solution on a glass plate in turn, and placing the glass plate in air at 50 to 75 DEG C and at a water relative humidity of 80 to 100 percent to obtain a primary ecological membrane; and immersing in running water for stripping the membrane and drying to obtain a polyvinylidene fluoride composite film of which the surface is super hydrophobic. In the invention, the method is simple, the process flow is short, the cost is low, and the prepared membrane has high flux and high salt rejection rate.

The invention discloses a preparation method of metformin hydrochloride. The preparation method is characterized by using dicyandiamide and dimethylamine hydrochloride as raw materials, feeding the materials in a mole ratio of (1:1)-(1:1.2), using N,N-dimethylacetamide or dimethyl sulfoxide 2-4 times dicyandiamide by weight as a solvent, and reacting for 4-8 hours at 140+/-5 DEG C to prepare a crude metformin hydrochloride product; recrystallizing the crude product with ethanol, regulating the pH value to be 5-6, decoloring the crystal, cooling the crystal to minus 10-0 DEG C while stirring, precipitating the crystal, obtaining a refined metformin hydrochloride product through filtering and drying, and recovering the solvent from filtrate. The qualified product has yield of 80-85% and high purity. The preparation method has the advantages that as the selected reaction solvent has a relatively high boiling point, the recovery rate of the solvent is high; the phenomenon of material surging can be effectively avoided, so that the preparation method has the advantages of mild reaction conditions, simplicity in operation and high safety.

The invention relates to a harmless dimethylacetamide wastewater treatment method which comprises the following steps of: (1) regulating the pH of wastewater in a regulating reservoir; (2) performing pretreatment in an iron carbon-Fenton oxidation pond; (3) performing flocculating sedimentation treatment; (4) adding a carbon source to perform hydrolytic acidification treatment; (5) performing anaerobic biochemical treatment in a primary upflow anaerobic sludge blanket (UASB) reactor; (6) performing anaerobic treatment in a secondary UASB (Upflow Anaerobic Sludge) reactor; (7) treating in an aerobic pond; (8) performing mud-water treatment in a secondary sedimentation tank to drain water. An aerated micro electrolysis method, a Fenton oxidation method and a biological method are combined; moreover, a good wastewater treatment effect is kept, the treatment cost is reduced, and the harmless dimethylacetamide wastewater treatment method has the obvious characteristics of high organic matter removal efficiency, stable effluent quality, low engineering investment, low energy consumption and the like, and is easy to popularize and apply.

The invention discloses a carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane and a preparation method thereof. The carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane is prepared by firstly, ultrasonically dispersing carboxylation graphene oxide in double solvents consisting of dimethylacetamide and triethyl phosphate, subsequently mixing with polyvinylidene fluoride, regulating the temperature to be 50-60 DEG C, mechanically stirring for dissolving, cooling to the room temperature, scraping a glass plate to form a membrane, soaking in deionized water for 3-5 days, and naturally drying in air, so as to obtain the carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane. The carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane disclosed by the invention is relatively good in hydrophilia and mechanical strength. The preparation method has the characteristics of simplicity, environment friendliness, easiness in condition control, short preparation period and the like.

The invention discloses a preparation method of a polyimide film, which relates to a preparation method of a high molecular polymer film. The invention aims at providing a synthesis method of a polybenzoxazole imide film containing a single oxazole ring, which solves the problem of poor film forming ability of polybenzoxazole imide containing a dual oxazole ring under a condition without sacrificing the thermal property of a polymer. The method includes the following steps: firstly, 5-amido-2-(phenetidine)benzoxazole and N, N'-dimethylacetamide are mixed and stirred and added with aromatic dianhydride and then a polyamide acid is obtained after reaction is finished; secondly, the polyamide acid prepared in the first step is casted into film and dried; thirdly, heat treatment is carried out; and fourthly, the polyimide film is obtained through water boiling and stripping. The polyimide film prepared by the method is good in thermal property, strong in acid resistance and high in mechanical property. The preparation method is simple and has good film forming performance.

The invention discloses a preparation method of nano-cellulose aerogel and relates to the preparation method of the nano-cellulose aerogel. The preparation method aims at solving the problem of poor dispersion of the existing cellulose aerogel in an organic solvent. The preparation method comprises the following steps: 1) dissolving absorbent cotton in a sulfuric acid solution for acidolysis, centrifugalizing, and then washing a white sol precipitate with deionized water to be neutral; 2) adding the nano-cellulose sol precipitate into the organic solvent, uniformly stirring, and then placing into an ultrasonic cleaning instrument for ultrasonic dispersion; and 3) placing a nano-cellulose suspension at the temperature of minus 18-minus 25 DEG C for freezing, and then further placing into a freeze-drying machine for freeze-drying. The nano-cellulose aerogel prepared by the invention has obvious nano-microfibril and nano-porous structure and can be rapidly dispersed in the organic solvent, such as dimethylformamide, dimethylacetamide and the like, the particle size of dispersed cellulose is nano-scale, and the good dispersion is shown. The preparation method disclosed by the invention can be applied to catalyst carriers, adsorbents and other fields.

The invention discloses an oceanic heavy corrosion resistant self-stratifying coating which is prepared by using a conventional preparation process under the coordination of all functional auxiliaries including epoxy resin-44 and fluorocarbon resin HFS-F-3000 as base stocks, Basf isocyanate as a curing agent, N-dimethylacetamide and dimethylbenzene as solvents, polyethylene glycol 600 as a dispersing agent and ferric oxide and zinc phosphate as pigments. The oceanic heavy corrosion resistant self-stratifying coating has favorable corrosion resistance and strong interlayer adhesion, and can be used for realizing one-step industrial coating, reducing processes, lowering cost and greatly increasing the actual production efficiency.

The invention relates to a high-dielectric constant low-loss metal/polymer composite and a preparation method thereof. According to the invention, self-passivating metal Al powder with average particle size of 800 nm is treated by a silane coupling agent, then uniformly mixed with N, N-dimethylacetamide (DMAC) solution of polyvinylidene fluoride (PVDF) by magnetic stirring and ultrasonic dispersion, coated on clean glass plates to form films, and then dried in vacuum at 80 degrees centigrade for 2 h to remove solvent so as to obtain Al/PVDF composites with thickness of 30-80 microns; wherein dosage of Al is 10-50% of PVDF by volume percent. The Al/PVDF composite provided by the invention has a dielectric constant higher than 58 under a frequency of 1 kHz at room temperature, and a dielectric loss lower than 0.02; the dielectric constant is linearly increased along with increment of Al content, so that the dielectric constant can be randomly regulated within certain range according to the need; at the same time, the dielectric constant is good in temperature and frequency stability.