84results about How to "Enhanced steric hindrance" patented technology

The invention discloses a preparation method of a synthetic type polycarboxylic acid water reducer. The synthetic type polycarboxylic acid water reducer has a solid content of 40-50%, and is prepared from the following raw materials in parts by weight: 100 parts of unsaturated polyoxyethylene ether, 7-15 parts of unsaturated acid, 4-10 parts of unsaturated ester, 1-3 parts of an amide derivative, 0.5-2 parts of an oxidant, 0.2-1.2 parts of a chain transfer agent, 0.3-2 parts of a reducing agent, 0.1-1 part of a crosslinking agent, 0.01-0.1 part of ferrous sulfate heptahydrate, 5-10 parts of a commercially available mud-resistant auxiliary agent, 90-130 parts of deionized water and an appropriate amount of liquid caustic soda. The preparation method disclosed by the invention adopts a normal-temperature oxidation-reduction initiating system to synthesize the synthetic type polycarboxylic acid water reducer which not only has functions of water reduction and slump loss resistance, but also has functions of mud resistance and early strength, heating is not needed for reaction, the energy consumption is reduced, and the production cost is greatly reduced.

The invention discloses a ceramic ink, which comprises the following raw materials in percentage by mass: 57-57% of ceramic powder, 1-5% of a dispersant, 8-30% of glycerol, 8-35% of water and 5-20% of an organic solvent; and the pH value of the ceramic ink is 8-12, and the dispersant is composed of ammonium polyacrylate and polyvinylpyrrolidone in a mass ratio of 1:5 to 5:1. The invention also discloses a preparation method of the ceramic ink and the application of the ceramic ink in the ink-jet printing of false teeth. According to the invention, the dispersion and ink stability of the ceramic ink are improved by a binary dispersant, and then the solid phase content of the ceramic ink is increased to 20-40 vol. %, so that the ceramic ink can be used for directly printing ceramic products such as false teeth and the like through ink-jet printing, and the relative density of ceramic products is more than 98%.

The invention discloses a preparation method of dispersant modified iron nanoparticles. According to the preparation method, high polymer, a cationic surfactant or anionic polymer electrolyte is used as a dispersant to perform surface modification on particles in a preparation process of the iron nanoparticles so as to prepare the dispersant modified iron nanoparticles. The iron nanoparticles prepared by the method have good dispersion stability; the hard agglomeration of the iron nanoparticles in an aqueous medium is reduced; the dispersion degree of the iron nanoparticles is increased; the method can also be used for performing dispersion modification on iron base bimetallic particles; and the method can be applied to pollution remediation of chlorinated organic compounds in an environmental medium and has broad application prospect.

The invention discloses zero-VOC (volatile organic compound) cement-based water-proof material copolymer emulsion and a preparation method thereof. The preparation method adopts a zero-VOC copolymer emulsion component A and an inorganic powder component B, the zero-VOC copolymer emulsion component A is prepared from deionized water, alkyl acrylate, styrene, acrylic acid functional monomers, emulsifying agents, initiators, a buffer agents, polymerization inhibitors, oxidizing agents, reducing agents, sterilizing agents and defoaming agents through polymerization of pre-emulsification semi-continuous seed emulsion, and the inorganic powder component B comprises ordinary portland cement, quartz sand and water reducers. The prepared emulsion is high in solid content, low in viscosity, uniformin particle size and good in stability and has excellent rheological property and coating water absorption, the content of a residual monomer in an emulsion product is lower than 300ppm and meets national zero-VOC emulsion standards, the emulsion is environmentally friendly and free from toxicity and pollution, the compatibility of the emulsion and cement is good, and a prepared polymer cement waterproof coating is excellent in water resistance, good in low-temperature flexibility and low in water absorption.

The invention relates to a preparation method for a comb-shaped copolymer cement dispersant, a monomer used in the comb-shaped copolymer cement dispersant and the prepared comb-shaped copolymer cement dispersant. The preparation method for the comb-shaped copolymer cement dispersant comprises the following steps: a monomer (a) and a monomer (b) are subjected to free-radical copolymerization in aqueous medium, wherein the monomer (a) is expressed with a general formula (I), and the monomer (b) is expressed with a general formula (II); and the mol ratio of the monomer (a) and the monomer (b) is preferably 1:(1 to 10). The structure formula of the comb-shaped copolymer cement dispersant obtained by the preparation method is shown in (VI). The new monomer (a) is introduced in the comb-shaped copolymer cement dispersant, and the molecular structure of the monomer (a) has an unsaturated reactive double bond and two branching polyoxyalkylene long chains, so that the steric hindrance among cement particles can be greatly enhanced, and the dispersion stability of cement can be enhanced. The preparation method for the comb-shaped copolymer cement dispersant is simple and convenient for production operation, and meanwhile, the prepared comb-shaped copolymer cement dispersant has the advantages of low dosage, good dispersivity, high water-reducing rate, small slump loss and low gas content.

The invention belongs to the technical field of extraction of plant effective components, and concretely relates to a low-cost and high-efficiency curcumin extraction method. The method sequentially comprises the following steps: taking crushed dry turmeric, carrying out extraction on the crushed dry turmeric by using ethanol, concentrating obtained extraction filtrate, extracting the concentrated filtrate with petroleum ether, re-concentrating the obtained extract, dissolving the obtained concentrate in an aqueous sodium hydroxide solution, extracting the obtained solution with ethyl acetate, and concentrating the obtained ethyl acetate layer to obtain a primary turmeric extract; and dissolving the primary turmeric extract in ethanol, and carrying out high-matching adsorption separation by adopting specially-produced modified attapulgite to respectively obtain a demethoxycurcumin and bisdemethoxycurcumin mixture and highly pure curcumin. The method fully utilizes the structural characteristics of the curcumin and the attapulgite, realizes high matching against the molecular difference, and has the advantages of convenience in operation, no large device demands, high extraction efficiency, low cost, effective separation of the curcumin from the demethoxycurcumin and the bisdemethoxycurcumin, high purity, and realization of industrial production.

The invention discloses a high-solid-phase-content aluminum oxide photosensitive ceramic material and a preparation method thereof. The preparation method comprises the following steps of: dispersingaluminum oxide ceramic powder into a surfactant dilute solution for modification treatment, and then performing drying and ball milling to obtain modified ceramic powder; mixing photosensitive resin,a plasticizer, a polymerization inhibitor, a dispersing agent and a photoinitiator to prepare a photosensitive premixed solution; and adding the modified ceramic powder into the premixed solution, fully dispersing the substance, and removing bubbles to obtain the high-solid-phase-content aluminum oxide photosensitive ceramic material. The ceramic photosensitive materials with the same solid phasecontent and different states are prepared so as to meet different requirements of various ceramic 3D printing.

The invention belongs to the technical field of OLED, and provides a compound with a structure shown in a formula (1), wherein D represents an electron donating group containing a nitrogen atom and isconnected to a benzene ring through the nitrogen atom, and A represents an electron accepting group containing a boron atom and is connected to the benzene ring through the boron atom; m and n are respectively selected from 1, 2 and 3; and R11, R12, R13 and R14 are respectively and independently selected from a hydrogen atom, an alkyl group, an alkoxy group, a cyano group, a trifluoromethyl group, the electron accepting group A' or the electron donating group D' containing the nitrogen atom. The compound adopts biphenyl as a connecting unit between the electron donating group D and the electron receiving group A, the D and the A achieve effective separation of HOMO and LUMO at different positions of molecules, and two physical processes of intramolecular charge transfer and space charge transfer can be simultaneously formed in the same molecule through connection of the biphenyl between the D and the A units, so that absorption of the molecules to light is improved, and the oscillatorstrength of the molecules is improved.

The invention discloses a viscosity-reducing type polycarboxylic acid water reducing agent preparation method, which comprises: (1) preparing an esterification monomer; (2) carrying out a copolymerization reaction; and (3) carrying out a neutralization reaction. According to the present invention, the viscosity-reducing type polycarboxylic acid water reducing agent is prepared by co-polymerizing 2-allyloxyethanol, a blend, VPEG, 2-methacryloyloxyethyl phosphorylcholine and an unsaturated acid, such that the phosphate radical, the carboxylate radical, the quaternary ammonium salt and the estergroup are introduced into the molecular structure of the polymer while the polymer structure is lightly cross-linked, wherein the product obtained by the esterification of the single carboxy in 2-phosphonobutane-1,2,4-tricarboxylicacid prepared by a 2-phosphonobutane-1,2,4-tricarboxylicacid esterification reaction, the product obtained by the esterification of the two carboxy in a small amount of2-phosphonobutane-1,2,4-tricarboxylicacid and the product obtained by the esterification of the three carboxy in a small amount of 2-phosphonobutane-1,2,4-tricarboxylicacid form the blend; and the prepared viscosity-reducing type polycarboxylic acid water reducing agent has advantages of viscosity reducing, water reducing, slump retaining and mud resistance, and can solve the problems of high viscosity, poor workability and rapid loss due to the high mud content in the current concrete raw materials.

The invention provides alkenyl carbonate polyethers. The general structure of the alkenyl carbonate polyethers is shown as follows, wherein R<1> is H or C1-C3 alkyl, R<2> is a C1-C5 alkylidene group, R<3> is a C2-C4 alkylidene group, a phenylene group or a benzylidene group, M is a polyether chain comprising one or more selected from -CH2CH2O-, -CH(CH3)CH2O- and -CH2(CH3)CHO-. The alkenyl carbonate polyethers comprise a carbonate group, thus facilitating enhancement of molecular chain toughness, and enhancing steric hindrance of synthesized water reducer molecules; and the carbonate group increases the side chain density of synthesized water reducers, and therefore dispersing performance of the water reducers can be improved. The carbonate group in the polyethers is high in electronegativity so that the prepared water reducers have certain functions of resisting slime adsorption. The polyethers are nontoxic, harmless, easily degradable and environmental friendly.

The invention relates to a polycarboxylate flow regulator for water-based drilling fluid and completion fluid with ultra-high temperature and ultra-high density and a preparation method of the polycarboxylate flow regulator. A zwitterionic polycarboxylate multi-polymer with a comb type structure is produced from alkenyl benzene sulfonate, strongly hydrophilic cationic alkenyl quaternary ammonium salt and allyl polyoxyethylene ether containing a specific long chain structure by free radical polymerization in an aqueous solution. A molecular chain of the produced multi-polymer contains 7-20 structural units with weight-average molecular weight in the range of 6,500-12,500. The polycarboxylate flow regulator can greatly reduce viscosity and shear force of the water-based drilling fluid and completion fluid with ultra-high temperature and ultra-high density, improve the dispersion state of solid phase weighting materials in the water-based drilling fluid and completion fluid, improve the rheological property of the water-based drilling fluid and completion fluid with ultra-high temperature and ultra-high density, obviously reduce surface tension of the water-based drilling fluid and completion fluid with ultra-high temperature and improve lubricating performance of the water-based drilling fluid with ultra-high temperature and ultra-high density, has shale inhibition performance and high temperature stability performance, and can resist high temperatures of 251 DEG C or higher.

The invention provides a method for organic surface modification of nanometer attapulgite. The method comprises the following steps: (1) inorganic surface modification of nanometer attapulgite: a step of heating dispersed and purified nanometer attapulgite aqueous dispersion to 40 to 100 DEG C and carrying out inorganic surface modification on nanometer attapulgite under stirring, wherein a surface coating substance of nanometer attapulgite is one, two or three selected from the group consisting of ZnO hydrate, Al2O3 hydrate and MgO hydrate, and in terms of oxide, a mass ratio of the inorganic coating substance to nanometer attapulgite is 5 to 30%; (2) organic surface modification of nanometer attapulgite: a step of the pH value of the inorganic surface coated nanometer attapulgite aqueous dispersion so as to allow the surface of nanometer attapulgite to be positively charged, then adding desired anionic surfactant under stirring, wherein a mass ratio of the anionic surfactant to nanometer attapulgite is 3% to 20% and the anionic surfactant is added after dissolving in deionized water, and continuing stirring for 5 to 600 min after completion of addition; and (3) post-treatment: a step of subjecting a product to solid-liquid separation, washing, drying and crushing after completion of a reaction so as to eventually obtain the anionic surfactant surface modified nanometer attapulgite.

The invention relates to an addition compound and a preparation method for the addition compound and a wetting dispersant containing the addition compound used in coating ink. The addition compound isa branched silicon-containing polymer prepared by a monomer mixture through an ester exchange reaction. The branched silicon-containing polymer dispersing auxiliary has a structure as shown in the following formula. An organic silicon component is introduced into the branched polymer, so wetting ability of the dispersant to solid particles is greatly reinforced through a silicon-containing component, and steric hindrance capacity of a branched polyether component to the solid particles is reinforced, an amino residue is bonded and anchored to the surface of the solid particles. While the branched polymer dispersing auxiliary is used for dispersing the solid particles, excellent comprehensive dispersing performance can be provided for an obtained dispersoid.

The invention disclose a complex dispersant water-based liquid magnetic grinding tool and a manufacturing method thereof, and belongs to the field of surface finishing of mechanical parts. The high-stability complex dispersant water-based liquid magnetic grinding tool is made of raw materials including, by mass percent, 65% to 80% of magnetic particles, 15% to 25% of deionized water, 0.5% to 3% of a surface active agent, 0.5% to 2% of an antioxidant, 0.3% to 1% of a moisturizing agent, 0.3% to 1.5% of a pH adjusting agent, 1% to 2% of nanoscale particles, and 7% to 10% of abrasive particles. The grinding tool has the beneficial effects the stirring manner based on seal pure rolling is provided, a complex dispersant is used and is combined with other function reagents to replace a single dispersant, the moisturizing agent is added in the formula, the water evaporation is reduced, the nanoscale particles are added, the effect of filling gaps between macromolecules is achieved, the space position resistance effect is improved, and the grinding tool has the beneficial effects of being stable, good in re-dispersion, good in fluidity, low in zero field viscosity, non-poisonous and convenient to recycle.