15 results about "Thiourea dioxide" patented technology

A method for preparing aryl-substituted alcohols, belonging to the field of organic synthesis. This invention solves the problem that existing visible light photocatalytic reactions for constructing carbon-carbon bonds by reversing the polarity of the C=O double bond require expensive and environmentally harmful metal photocatalysts. Method: Aromatic aldehydes, 4-cyanopyridine, tetrabromofluorescein, thiourea dioxide, potassium carbonate, and an organic solvent are mixed, followed by light irradiation. This invention is used for the preparation of aryl-substituted alcohols.

The invention relates to the technical field of metal material surface treatment, in particular to a deplating agent for an aluminum alloy coating and a preparation method of the deplating agent, and the deplating agent comprises the following raw materials in parts by weight: 15-35 parts of an alkaline substance, 5-10 parts of an alkali stabilizer, 1-5 parts of a modified chelating dispersant, 1-5 parts of a scale inhibition enhancer, 1-5 parts of a modified corrosion inhibitor and 5-10 parts of a wetting agent. Wherein the modified corrosion inhibitor is obtained by taking mesoporous silica as a carrier, carrying out amination modification, loading multi-component composite corrosion inhibition components (thiourea, thiourea dioxide and benzotriazole), coating with polyacrylic acid and finally modifying with cerium ions and polyepoxysuccinic acid; the modified chelating dispersant is obtained by compounding beta-cyclodextrin and sodium polyacrylate; the deplating agent is prepared by adopting a specific ratio and a specific preparation process, and the deplating agent is extremely low in corrosion rate to an aluminum matrix while efficiently deplating a plating layer, and can also effectively prevent a workpiece from being corroded and dirt from being deposited on the surface of the workpiece.

This invention relates to the field of nonwoven fabric preparation technology, specifically to a biochemically modified antibacterial nonwoven fabric and its preparation method. This invention modifies nano-zinc oxide and nano-titanium dioxide using the silane coupling agent KH-570, improving the dispersibility of the nanoparticles. Under light or contact conditions, the nanoparticles release reactive oxygen species to disrupt bacterial cell membranes and inhibit their metabolism, thereby giving the antibacterial modified polypropylene masterbatch stable antibacterial properties. Furthermore, this invention stabilizes the loading through a polydopamine coating, thus stabilizing the antibacterial properties of lysozyme. Lysozyme specifically hydrolyzes the peptidoglycan layer of bacterial cell walls, leading to bacterial lysis. Thiourea dioxide, as a reducing agent, maintains lysozyme activity, preventing oxidative inactivation, while simultaneously inhibiting bacterial metabolic enzyme activity. Through the synergistic effect of inorganic and biological dual-effects, this invention can cover Gram-positive bacteria, Gram-negative bacteria, and fungi, thereby improving the antibacterial properties of the nonwoven fabric to a certain extent.

The application discloses a cement chromium-removing grinding aid and a preparation method thereof, and belongs to the technical field of cement admixtures. The cement chromium-removing grinding aid comprises the following raw materials in parts by weight: an inorganic reducing agent 25-50 parts, an organic reducing agent 5-15 parts, an alcohol amine type grinding aid component 8-20 parts, an anti-crystallization agent 0.5-3 parts, a complexing stabilizer 1-5 parts, a synergist 3-5 parts, and water 20-40 parts, wherein the synergist is a compound of sulfur dioxide and propylene glycol alginate. The compound synergist added innovatively in the application not only reinforces the chromium-removing efficiency and long-term effectiveness of the main reducing agent, but also cooperates with the alcohol amine to improve the grinding and yield increasing effect, stabilizes the grinding aid system, and optimizes the cement construction performance, so that the cement chromium-removing grinding aid realizes the comprehensive effects of efficient chromium removal, storage stability and excellent performance.

The invention belongs to the technical field of textile chemical industry, and particularly relates to a preparation and low-temperature bleaching method of primary-color alginate fibers, in particular to a low-temperature bleaching process. Aiming at the problems of non-uniform whiteness, large damage caused by traditional oxidation bleaching and the like of alginate fibers due to raw material difference, a reduction bleaching process is innovatively adopted, thiourea dioxide or sodium hydrosulfite is used as a bleaching agent, a mixed solution of sodium metasilicate and sodium hydroxide is used as an alkaline agent, and bleaching is performed under the conditions that the pH is 7-11 and the temperature is 40-80 DEG C. According to the method, through the synergistic effect of the alkaline agent and the bleaching agent and in combination with a calcium chloride protection mechanism, fiber damage is remarkably reduced, the whiteness is stably larger than or equal to 50, process wastewater pollution is low, and clean production is achieved. According to the invention, the technical bottleneck of alginate fiber bleaching is broken through, and the application range of alginate fiber in high-grade textiles is widened.

The invention discloses a complexing-reduction synergistic environment-friendly stripping method for a chinlon dyed fabric, and belongs to the technical field of textile dyeing and finishing. According to the method, aiming at the pain points of great fiber damage, low stripping efficiency and difficulty in wastewater treatment in the traditional stripping technology, a synergistic stripping system with the pH value of 10-11 is constructed by taking disodium ethylene diamine tetraacetate as a metal complexing agent, thiourea dioxide as a reducing agent, trisodium phosphate as a pH buffering agent and fatty alcohol-polyoxyethylene ether as a fiber protective agent. The method comprises the following steps: preparing a stripping solution containing components with specific concentration, feeding the chinlon dyed fabric according to a bath ratio of 1: 100, preheating to 85-90 DEG C, maintaining the pH value to be stable, supplementing a reducing agent, stripping at 85-90 DEG C for 35-60 minutes, finally washing with water for 2-3 times at the temperature of 25-30 DEG C, and airing at the temperature of 20-25 DEG C. The stripping rate is larger than or equal to 95%, the fiber melting point fluctuation is smaller than or equal to 2.2 DEG C, strength damage to polyamide fibers is remarkably reduced, reagent toxicity is low, waste water is easy to treat, and the method is suitable for stripping of polyamide fabrics dyed by metal complex dyes.

This invention discloses a precise feeding control system and process for synthesizing thiourea dioxide, relating to the field of fine chemical synthesis technology. The precise feeding control system includes a control unit, a solid feeding unit, and a liquid feeding unit. The control unit precisely regulates the feeding of each unit based on the reaction molar ratio of thiourea, hydrogen peroxide, and deionized water. The solid feeding unit achieves a thiourea feeding accuracy of ±0.1%; the liquid feeding units control the feeding of hydrogen peroxide and deionized water respectively, with accuracies of ±0.05% and ±0.1%. In the process, the precise feeding control system is first calibrated, then thiourea, hydrogen peroxide, and deionized water are added according to a molar ratio of 1:1.06~1.08:3.5~4.0, reacted at a constant temperature of 25~35℃ for 2.0~2.5h, followed by aging at 10~15℃ for 0.5~1.0h, vacuum filtration, washing, and drying to obtain the product. This invention improves the accuracy of the reaction raw material ratio and reaction stability, optimizes the thiourea dioxide synthesis process, and increases the reaction conversion rate of thiourea dioxide.

The invention discloses a thiourea dioxide-nano selenium sol anion source precursor solution preparation method, which comprises: adding inorganic salt of selenium and a dispersant into deionized water, completely dissolving to prepare a selenium salt solution, and gradually adding a reduction solution into the selenium salt solution to prepare a nano selenium sol; gradually adding a thiourea dioxide solution into the nano-selenium sol, and stirring to obtain a TD-Se mixed solution; the preparation method comprises the following steps: adding inorganic salt of indium and inorganic salt of copper into deionized water, dissolving to prepare an indium-copper salt solution, adding a complexing agent into the deionized water to prepare a complexing solution, adding the indium-copper salt solution into the complexing solution, and mixing to obtain an indium-copper complex solution; adding the indium-copper complex solution into the TD-Se mixed solution, and stirring to obtain a precursor solution; in the preparation of the precursor solution, vacuum and high-temperature environments are not needed, so that a high-temperature selenylation step is avoided; water is used as a single solvent and is environment-friendly; the nano-selenium sol is high in stability and can be stored for a long time.

This invention discloses a method for extracting high-purity lignin using thiourea dioxide. The method involves extracting lignin from bamboo powder using thiourea dioxide. After optimization, the optimal process conditions for separating bamboo lignin using thiourea dioxide are: NaOH concentration 18 g / L, solid-liquid ratio 1:15 (g / mL), reaction temperature 120℃, and reaction time 8 h. Under these optimal conditions, the lignin content in bamboo powder decreased from 26.77% to 8.14%, the lignin extraction rate was 16.30%, and the lignin purity was 89.2%, all superior to alkali extraction. Analysis of infrared spectroscopy, ultraviolet absorption spectroscopy, elemental analysis, and two-dimensional HSQC NMR spectroscopy showed that the carbon content of the lignin was low, and the molecular weight of the obtained lignin was also low (Mw = 3505 g / mol). Thiourea dioxide is an inexpensive reducing agent in industry. This research provides a new process for the extraction and preparation of lignin, offering a better and cheaper method for extracting water-soluble lignin.

The application provides a method for step-by-step precipitation and recovery of vanadium from vanadium-containing chromium wastewater, and belongs to the technical field of industrial wastewater treatment and metal resource recovery. The method comprises the following steps: mixing acid vanadium-containing chromium wastewater with sulfur dioxide hydride, placing the mixture under ultraviolet light to perform photocatalytic reduction reaction, and obtaining wastewater containing divalent vanadium and trivalent chromium; adjusting the pH of the wastewater containing divalent vanadium and trivalent chromium to a first alkalinity, performing solid-liquid separation, and obtaining trivalent chromium hydroxide precipitate and divalent vanadium-containing filtrate; adjusting the pH of the divalent vanadium-containing filtrate to a second alkalinity, performing solid-liquid separation, and obtaining divalent vanadium hydroxide precipitate. The application uses ultraviolet light to excite sulfur dioxide hydride, reduces vanadium and chromium in the acid vanadium-containing chromium wastewater into divalent vanadium and trivalent chromium, and realizes the recovery of vanadium through step-by-step precipitation by utilizing the pH difference of the precipitates.

The invention discloses a method for decolorizing a bisphenol AF crude product without using activated carbon, which is characterized by comprising the following steps: dissolving the bisphenol AF crude product in an acetone-water mixed solvent, adjusting the pH value to be a weak acid reaction system, adding a reducing agent thiourea dioxide, stirring and reacting for 1-4 hours at a set temperature, cooling and filtering to obtain a decolorized crude product, and filtering to obtain the decolorized bisphenol AF crude product. And adding the decolorized crude product into a diethyl ether-dichloromethane mixed solvent, stirring for a certain time at 40 DEG C, then cooling to 5-20 DEG C by a program, crystallizing, and filtering to obtain a white solid. According to the method, thiourea dioxide is used as a reducing agent, thiourea dioxide is released in a weak acid system, benzoquinone pigments are selectively reduced, bisphenol AF with the purity of 99.7% can be obtained after recrystallization, the yield is 92.6%, the color is bright and white, reaction operation is simple, the reducing agent is cheap and easy to obtain, the yield and purity are high, the decoloration time is short, the production cost is low, and environmental protection is achieved; the generation of activated carbon solid waste in a traditional treatment method is avoided, and the economic benefit is greatly improved.

The invention discloses a water quality total phosphorus rapid detection reagent and a preparation method thereof, and relates to the technical field of water quality total phosphorus detection, and the water quality total phosphorus rapid detection reagent comprises a digesting agent, a color developing reagent and a reducing reagent. Anhydrous ytterbium trifluoromethanesulfonate added into the color developing reagent can activate a polyethylene glycol diglycidyl ether epoxy group, the reaction time of the color developing reagent is shortened, ammonium molybdate tetrahydrate is added to dissociate high-purity molybdate to serve as a core active component of the reaction, polyethylene glycol diglycidyl ether and molybdate react accurately, and the purity of the molybdate is improved. Molybdate with a uniform structure is formed, and the storage stability is improved. According to the reduction reagent, through the synergistic effect between thiourea dioxide and an L-cysteine material, L-cysteine does not influence the directional reduction capacity of thiourea dioxide, and a reduction product of thiourea dioxide does not interfere the complexing function of L-cysteine, so that the reduction reagent has the advantages of efficient reduction and long-term stable preservation.

This invention belongs to the field of pharmaceutical synthesis technology, specifically relating to a method for preparing chloroprocaine hydrochloride and its intermediates, and their applications. The invention uses 2-chloro-4-nitrobenzoic acid and N,N-diethylethanolamine as starting materials, and prepares nitrochlorocaine via sulfuric acid-catalyzed esterification. Nitrochlorocaine is then reduced with thiourea dioxide to obtain crude chloroprocaine. The crude chloroprocaine is then salted in hydrochloric acid and ethanol, crystallized, and dried to obtain the final product, chloroprocaine hydrochloride. This method features low cost, high product quality, high yield, simple process, high production capacity, environmental friendliness, and suitability for industrial production, thus possessing significant industrialization value.