55results about How to "The synthesis process is stable" patented technology

A process for preparing the leimosiqiong hydrochoride from tetrahydrobenzoimidazole includes protecting by cycloacyl, arylcarbonylating, and acid hydrolyzing. Its advantages are high output rate (70%).

The invention relates to a method for preparing butyl rubber by catalytic polymerization. The method comprises the following steps: contacting an isobutene monomer with an isoprene monomer at the temperature of minus 75 DEG C-minus 50 DEG C in the presence of an aliphatic series hydrocarbon diluent and a catalyst composite so as to carry out a cationic polymerization reaction, wherein the amount of added isobutene is 80-85% of the total volume, and the weight of added isoprene is 2.90-2.97% of that of isobutene, the allowance is the aliphatic series hydrocarbon diluent based on volume, the content of aluminium diethyl monochloride in the added catalyst composite is 0.13-0.23% of the mass of isobutene, the addition weight of ethylaluminum dichloride is 8.2% of that of aluminium diethyl monochloride, and the addition mass of water is 10-16% of that of the added diethylaluminum. The catalyst composite is stable in property, and butyl rubber with high dialkene content and molecular weight is formed at the polymerization reaction rate.

The invention relates to a preparing method of edaravone, and belongs to the technical field of preparation of heterocyclic compounds. The preparing method of edaravone comprises the steps of carryingout a reaction between phenylhydrazine and ethyl acetoacetate at 25-30 DEG C for 1-4 h in an organic solvent, and then removing the solvent to obtain an oily substance, wherein the mole ratio of phenylhydrazine to ethyl acetoacetate is 1:(1.019-1.080); uniformly mixing the obtained oily substance with acetic acid, carrying out a reflux reaction at 105-115 DEG C for 6-10 h, then removing unreactedacetic acid, then adding an alcohol solvent for uniform mixing, and conducting soil-liquid separation to obtain edaravone. According to the preparing method of edaravone, by controlling the reactioncondition, stepwise reactions are carried out, the reaction process is more easily controlled, the content of impurities in the product is also greatly reduced, particularly, the contents of residualphenylhydrazine and derivative impurities thereof can be reduced, the genotoxicity of the product is greatly lowered, and the safety of using edaravone is improved.

The invention discloses a preparation method of high-temperature-resistant and corrosion-resistant fluorine-containing organic silicon/SiO2 nano-hybrided coatings, which comprises the following steps: by taking tetraethoxysilane, methylphenyldimethoxysilane and dodecafluoroheptylpropyl methyl dimethoxysilane as precursors, and preparing a fluorine-containing organic silicon/SiO2 hybrided sol by using a sol-gel method. The mole ratios of reaction components are as follows: the mole ratio of tetraethoxysilane, methylphenyldimethoxysilane and dodecafluoroheptylpropyl methyl dimethoxysilane is (0.001-500):(0.001-500):(0.001-200); and the mole ratio of anhydrous ethanol, distilled water, an acetic acid and total Si is (0.001-500):(0-100):(0.0001-50):(0. 01-1000). A coating obtained through curing the sol subjected to film coating has good high temperature resistance, corrosion resistance, hydrophobic properties and mechanical properties.

The invention discloses a synthesis method of peelable water-based polyurethane resin for a car cover. The synthesis method comprises the following steps: firstly, adding polytetramethylene ether glycol and polyether-modified organosilicone into a reaction container, performing vacuum dewatering, introducing nitrogen, dropwise adding diisocyanate into the reaction container, and reacting to obtain a prepolymer I; cooling the prepolymer I to 60 DEG C or below, adding dried polyhydroxycarboxylic acid into the reaction container, then dropwise adding dihydric alcohol into the reaction container, and reacting to obtain a hydrophilic group-containing prepolymer II; cooling the prepolymer II to 45 DEG C, dropwise adding diamine into the reaction container, and reacting to obtain a prepolymer III; and adding organic amine into the prepolymer III, neutralizing to form salt, and then adding diamine diluted with deionized water, stirring for 30-60 min, and emulsifying to obtain the peelable water-based polyurethane resin for the car cover, having the solid content of 30-45%. The peelable water-based polyurethane resin for the car cover, prepared by the synthesis method provided by the invention, improves the water resistance and the aging resistance of the car cover on the premise of easy peeling.

The invention provides a polyurethane foam stabilizer and a preparation method. The preparation method comprises the following steps of synthesizing of silicone oil with low hydrogen content, synthesizing of unsaturated polyether, synthesizing of isocyanate-terminated unsaturated polyether, and reacting of the silicone oil with low hydrogen content and the isocyanate-terminated unsaturated polyether, so as to obtain the polyurethane foam stabilizer. The preparation method has the advantages that the unsaturated polyether-terminated polyester uses isocyanate as a end-capping reagent, the usage amount is less, the reaction time is short, the waste salt is not produced, the product quality is stable, and the cost is low; the reaction activity is strong, the property is excellent, the problem of existence of terminating in the existing alkyl terminating and unsaturated polyether is solved, and the variety of the existing polyurethane foam stabilizer is enriched by adjusting the type of the isocyanate end-capping reagent.

The invention discloses a tetra-azido alkane and a preparation method thereof. A structural formula of the tetra-azido alkane is (N3CH2)2CH(CH2)3CH(CH2N3)2. The preparation method comprises the following steps of: under the protection of nitrogen, reacting diethyl malonate and 1,3-dibromopropane at a low temperature to obtain tetracthyl-1,1,5,5-pentanctetracarboxylate; under the protection of the nitrogen, carrying out ice bath at below 5 DEG C, and reacting the tetracthyl-1,1,5,5-pentanctetracarboxylate and a tetrahydroaluminate diethyl ether solution to obtain 2,6-dihydromethyl-1,7-heptandiol; carrying out the ice bath at below 5 DEG C, reacting paratoluensulfonyl chloride and a pyridine solution of the 2,6-dihydromethyl-1,7-heptandiol for 10h, and carrying out chloroform recrystallization to obtain 2,6-p-ditoluenosulfonate methyl-1,7-p-ditoluenosulfonate methyl heptaester; and adding an aqueous solution of sodium azide to a dimethylformamide solution of the 2,6-p-ditoluenosulfonate methyl-1,7-p-ditoluenosulfonate methyl heptaester to react for 15h at 80 DEG C to obtain a 2,6-biazido-1,7-di-azido heptane product.

The invention relates to a method for synthesizing an aluminum citrate cross-linking agent in a low carbon solvent. (1) the weight part proportions of chemical raw materials are as follows: 100-140 parts of methanol, 40-60 parts of ethanol, 40-100 parts of citric acid, 30-60 parts of aluminium chloride hexahydrate, 10-20 parts of sodium hydroxide and 20-30 parts of water. (2) the method comprises the following chemical reaction process steps of: firstly mixing methanol and ethanol according to the proportion under a normal pressure; adding citric acid to the above mixture to make citric acid dissolved completely; adding aluminium chloride hexahydrate under stirring; heating to a temperature of 40-80 DEG C; reacting for 4 hours; dropwise adding a sodium hydroxide solution slowly to adjust a pH value to 5.5-8.5; finally, adding a residual component of water, stirring uniformly, and thus the aluminum citrate cross-linking agent is obtained. The aluminum citrate cross-linking agent synthesized by the method has stable gel-forming properties and controllable gel-forming time, and has no sulfate ions and nitrate ions. The synthetic process is gent and easy to operate, has no generation of industrial waste materials, and is economic and environment-friendly.

The invention relates to phosphate-modified waterborne epoxy ester resin and an anti-corrosive primer thereof, and preparation methods of the phosphate-modified waterborne epoxy ester resin and the anti-corrosive primer. A scheme provided by the invention comprises the phosphate-modified waterborne epoxy ester resin and the preparation method thereof. The waterborne epoxy ester anti-rust primer with excellent anti-rust performance is prepared by taking the phosphate-modified waterborne epoxy ester resin as a base material and cooperatively using a non-toxic and efficient anti-rust pigment. Compared with the prior art, epoxy resin and phosphoric acid are esterified to synthesize epoxy phosphate, then the epoxy phosphate and acrylate monomers are subjected to graft copolymerization, so the phosphate modified waterborne epoxy ester resin with excellent performance is prepared, and the salt spray resistance of the anti-rust primer is further improved.

The invention provides a woven reinforced degradable polyurethane elastomer artificial blood vessel and a preparation method thereof. The inner layer of the artificial blood vessel adopts activated H2N-PEG-COOH, heparin and (Mpa)-GGGGGREDV polypeptide to treat a C-PEEUU-NH2 electrospun nanofiber tubular stent to obtain a C-PEEUU-PEG-Hep/REDV tubular stent, the middle layer adopts a woven reinforced layer of nanofiber yarns woven by dissolving and mixing one or more master batches of PLGA, PDO and PGA according to a mass ratio, and the outer layer is a macroporous layer prepared by thermally induced phase separation. The woven reinforced degradable polyurethane elastomer artificial blood vessel provided by the invention can be used for tissue regeneration and construction of cardiovascularand cerebrovascular diseases, the preparation method is simple and efficient, the price is low, and the prepared artificial blood vessel has resilience, compliance, bursting strength and biocompatibility matched with autologous vascular tissues. The artificial blood vessel has no hypersensitivity to a human body in a transplantation operation, has affinity with blood and peripheral tissues in thehuman body, and has a good application prospect in repair operations of cardiology surgery, nephrology surgery and brain surgery.

The invention belongs to the technical field of synthesis of steroidal intermediate chemicals, and particularly discloses a steroidal intermediate chemical and a preparation method and application thereof. The steroidal intermediate chemical can be used for synthesizing plant growth regulators, steroidal drugs and the like, stigmasterol serves as a raw material, and the steroidal intermediate chemical is obtained through three-step reactions of sulfonylation, rearrangement, manganese dioxide selective oxidation. The synthesis process is stable and easy to operate, and conditions are mild and easy to control; raw materials are rich in source and easy to obtain; purification is not needed in the intermediate process, the technological process is simplified, the solvent is easy to recover, and cost is reduced; and meanwhile, sewage and waste discharge is reduced, industrialization is facilitated, and high economic and social benefits can be brought.