229results about How to "Increased steric hindrance" patented technology

The invention discloses an ester slump retaining type polycarboxylate water reducer and a preparation method thereof. The ester slump retaining type polycarboxylate water reducer is made from raw materials comprising the following components in parts by weight: 100 parts of esterified macromer solution by weight, 2-6 parts of unsaturated monomer by weight, 1.5-4 parts of unsaturated phosphate by weight, 1-4 parts of an oxidizing agent by weight, 0.9-3.5 parts of a reducing agent by weight, 1-3 parts of a chain transfer agent by weight, 108 parts of water by weight, and 20 parts of industrial sodium hydroxide solution by weight, wherein the concentration of the esterified macromer solution is 75-85%, and a solute thereof is the mixture of methoxy polyethylene glycol methacrylate, crosslinking monomers triethylene glycol dmethylacrglate and methyl methacrylate; the unsaturated monomer is methacrylic acid, acrylic acid, hydroxyethyl methylacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate or hydroxypropyl acrylate. The ester slump retaining type polycarboxylate water reducer provided by the invention has good slump retaining performance, good dispersibility, good adaptability and low cost.

The invention relates to a filament low-melting-point polyester fiber and a preparation method thereof. The filament low-melting-point polyester fiber is in a skin-core structure, a skin layer is made of low-melting-point polyester; a core layer is made of PET (polyethylene terephthalate); the low-melting-point polyester consists of a terephthalic acid chain segment, an isophthalic acid chain segment, an ethylene glycol chain segment, a diethylene glycol chain segment, a molecular weight modifier chain segment and a 1, 12-Dodecanediol chain segment containing branched chains; a molecular weight modifier corresponding to the molecular weight modifier chain segment is specifically a monoacid series or a diacid series; the preparation method of the filament low-melting-point polyester fiber comprises the following steps: polymerization of the low-melting-point polyester and skin-core composite spinning, so as to obtain the filament low-melting-point polyester fiber. The prepared filament low-melting-point polyester fiber has the advantages that the initial melting point is reduced, the melting speed is increased, the polyester fiber is immediately melted at the corresponding temperature, and the melting effect is good.

The invention provides a pyridine-fluorene organic electrophosphorescence main body luminescent material and a preparation method thereof, relating to new-generation organic luminescent display materials and technology. Due to the rigid structure, the luminescent material has high triplet energy level and favorable hole injection and transmission performance; and due to the three-dimensional large-volume steric hindrance effect, the luminescent material has stable amorphous state, and thus, can be widely used in organic light-emitting diodes. The specific design structure of the pyridine-fluorene main body material is disclosed in the specification. The invention particularly relates to a preparation method and application in organic light-emitting diode devices. The material has the advantages of high luminescence efficiency, high heat stability, high glass transition temperature and simple synthesis method, and can effectively inhibit concentration quenching and dimer luminescence. The preliminary structure as the main body material implements red-green-blue tricolor organic electroluminescent devices. The compounds have wide application prospects and huge commercial value in the aspects of electrophosphorescent main body materials.

The invention discloses a phosphono-group-containing water reducing agent and a preparation method thereof. The phosphono-group-containing water reducing agent is in a comb-like structure, wherein the main chain has an acid anhydride group, carboxylate group or amido group; the main chain does not provide the initial water reducing capacity, but releases adsorption groups after being hydrolyzed under alkaline conditions in the later period, thereby enhancing the slump retaining capacity; side chains comprise pure polyether side chains and polyether side chains with an adsorption group at the terminal; the pure polyether side chains provide steric hindrance; and the adsorption groups comprise phosphono groups and phosphorous acid groups, and have multiple and centralized adsorption sites, thereby providing the initial adsorption capacity and dispersion capacity of the water reducing agent. The main adsorption groups in the phosphono-group-containing water reducing agent are phosphono groups; and carboxylates or acid anhydrides in the water reducing agent structure can continuously release new carboxyl adsorption groups through the reaction of water under alkaline conditions in the later adsorption period, thereby achieving better slump retaining properties.

The invention discloses a preparation method for a high-slump-retention polycarboxylate water reducer. The preparation method comprises the following steps of: esterifying methoxylpolyethylene glycol monomethyl ethers with different molecular weights with methacrylic acid and a mixed polymerization inhibitor for a period of time under the action of a catalyst and at a certain temperature, then adding allyl alcohol in one time, further esterifying in the same conditions to obtain an esterified macromonomer MP containing crosslinking monomer allyl methacrylate; then performing aqueous solution polymerization on the MP, unsaturated sulfonate, (meth)acrylate unsaturated monomers and a chain transfer agent in a low-temperature condition and within a redox initiation system; and finally adding caustic soda liquid to neutralize, so as to obtain the polycarboxylate water reducer with a certain concentration. The high-slump-retention polycarboxylate water reducer prepared by the preparation method disclosed by the invention is a high-performance water reducer which is prepared at a low temperature by virtue of a molecular structure design, as well as is high in slump retention, excellent in dispersing performance, good in adaptability, simple in process, pollution-free, low in energy consumption, and easy to realize industrialized production.

The invention provides a super-early-strength PCE (polycarboxylate ether) superplasticizer. The super-early-strength PCE superplasticizer is a compound shown in formula (I) and is synthesized with active macro-monomers used as raw materials, the space hindrance effect of the superplasticizer is further improved, and meanwhile, positive ions with good cement resistance are introduced in molecules, so that the superplasticizing rate, the cement resistance and the cement adaptability of the superplasticizer are increased. The superplasticizer has better tolerance and cannot have a continuous intercalation reaction with the cement. The positive ions of the super-early-strength PCE superplasticizer can inhibit expansion of the cement so as to reduce adsorption of the cement to an additive. The super-early-strength PCE superplasticizer can accelerate the hydration function of the cement and has the super-early-strength function. The super-early-strength PCE superplasticizer has super-early-strength and cement-resistant functions in common concrete.

The invention discloses a preparation method of amorphous monodisperse nano silicon dioxide powder with controllable granularity and belongs to the field of an inorganic non-metal powder material. The preparation method comprises the specific steps: in a methanol solvent, selecting a silicon-containing organic matter as a silicon source and synthesizing silicon dioxide sol by utilizing an ammonia water catalyzed Stober method; ageing to obtain silicon dioxide gel; freezing and drying the gel to obtain silicon dioxide powder; mixing the powder and ethanol to form slurry and carrying out ball milling for 1h to 24h; drying in a drying oven at 50 DEG C to obtain the monodisperse amorphous silicon dioxide powder with the granularity in a range of 10nm to 100nm. A preparation process of the silicon dioxide powder is simple and the cost of the raw materials is low; large-scale industrial production of the silicon dioxide powder is easy to realize.

The invention provides a superfine oil-base drilling fluid used for a high temperature high pressure superdeep well, the superfine oil-base drilling fluid contains the following raw materials by weight: 20-40 parts of water, 250-500 parts of diesel, 2-10 parts of an emulsifier, 3-15 parts of a wetting agent, 2-8 parts of organic soil, 15-25 parts of a filtrate loss agent, 5-10 parts of calcium chloride, 5-10 parts of calcium oxide, 450-800 parts of API barite, and 350-660 parts of an ultra aggravating material. The oil-base drilling fluid is weighted by compounding superfine mineral powder and ordinary barite, the superfine high density oil-base drilling fluid density can reach 2.8g / cm<3>, has better settling stability and high temperature and high pressure filtration loss compared with that of ordinary barite weighted drilling fluid, and can meet drilling of deep wells, superdeep wells and composite salt formations.

The invention relates to a sand-containing colorful environment-friendly coating and a preparation method of the same. The coating is composed of a pigment component, a dispersion medium and varnish; the pigment component includes RO water, cellulose, a dispersant, pigments and fillers, a defoamer, a film forming additive, an emulsion, an anti-freeze agent, an inorganic protective glue solution, a pH regulator, a sterilizing agent, a first thickener, and natural colorful sands; the dispersion medium includes RO water, the film forming additive, a rheological agent, the emulsion, an organic protective glue solution, the defoamer and a coupling agent; and the varnish includes RO water, the emulsion, the pH regulator, the sterilizing agent, the defoamer, the film forming additive, the anti-freeze agent, and a second thickener. Compared with the prior art, the sand-containing colorful environment-friendly coating has good storage and construction stability, wherein a dried film of the coating is excellent in adhesion force and water resistant performance. The coating, when being used, has a good rough sense and has clear layer sense, thereby representing a texture effect of natural stone materials better.

The invention relates to a polycarboxylic acid water reducer, and particularly relates to a room temperature synthesis method for a polycarboxylic acid high slump retaining water reducer. The method comprises steps of putting water, unsaturated polyoxyethylene ether, acrylic acid alkyl ester and amides monomer into a reaction kettle without heating, stirring to be dissolved, putting an oxidant solution into the reaction kettle, then simultaneously dripping a liquid A and a liquid B which are prepared in advance into the reaction kettle and finishing dripping the liquid A and the liquid B simultaneously in one hour, preserving heat for one hour, then adding alkali liquor to be neutralized till the pH is 6-7, supplementing water so as to obtain 40% polycarboxylic acid high slump retaining water reducer, wherein the liquid A is acrylic acid, a chain transfer agent and water, and the liquid B is a reducible catalyst. The method introduces a hydrophobic side chain into the water reducer and changes the electrical nature of the water reducer molecule, has a short reaction cycle for the room temperature reaction spends only 2 hours, and has high production efficiency.

The invention relates to a preparation method of graphene bonding modified silica fume. The method comprises steps as follows: 1) carboxylated graphene and a silane coupling agent KH550 solution have a reaction under the action of a catalyst, so that coupling modified graphene is obtained; 2) then the coupling modified graphene reacts with the silane coupling agent KH550 solution, and KH550 sol containing the coupling modified graphene is obtained; 3) the KH550 sol reacts with surface hydroxylation modified silica fume, and the graphene bonding modified silica fume can be prepared. The method has the benefits as follows: (1) the strength of cement based composite materials can be significantly enhanced, so that the silica fume has the higher dispersity as well as excellent electrical properties; (2) concrete can have the higher flowing property; (3) the strength (especially the bending strength) of cement concrete can be enhanced, and the toughness of the cement concrete is improved; (4) the application range of the concrete is wider.

The invention relates to a method for preparing a nano copper particle, in particular to a novel method for preparing a nano copper particle serving as a lubricating oil additive. The synthesis method comprises the following steps of: dissolving water-soluble divalent copper salt into water; adding a proper amount of acid organic extracting agent and coating agent into the solution; extracting divalent copper ions to an organic phase; and then simply and efficiently preparing spherical nano copper particles which have good dispersion, uniform particle size and good oxidation resistance by adopting a two-step liquid phase reduction method. The method provided by the invention has the advantages such as simple process, convenience for operation, low cost, easiness for industrialization and the like; and the prepared nano copper particle has the advantages of good dispersion, uniform particle size, good oxidation resistance, good friction property and the like.

The invention provides a polycarboxylate superplasticizer with super high early strength. The polycarboxylate superplasticizer with super high early strength is a compound shown in the formula (I) and is synthesized with an active macromonomer as the raw material, cations are introduced into molecules while the steric hindrance effect of the superplasticizer is further improved, the cations have good soil resistance, so that the water-reducing rate of the superplasticizer is increased, and the soil resistance and the cement adaptability of the superplasticizer are improved. The polycarboxylate superplasticizer has better tolerance for soil and does not have an intercalation reaction with the soil. The cations of the polycarboxylate superplasticizer with super high early strength can inhibit soil expansion, so that admixture adsorption by the soil is reduced. The polycarboxylate superplasticizer with super high early strength can accelerate hydration of cement and has the super high early strength function. The polycarboxylate superplasticizer with super high early strength has super high early strength and soil resistance functions when applied to common concrete.

The invention provides an asphalt emulsifier, belonging to the technical field of asphalt pavement cold recycling technology. The asphalt emulsifier comprises the following components by weight percent: 30-60% of fatty acid amide, 10-30% of modified alkali lignin and 10-40% of alkyl amido betaine; the modified alkali lignin is prepared from the following raw materials: trimethylamine hydrochloride, epichlorohydrin and alkali lignin; due to the fatty acid amide, modified alkali lignin and ampholytic surfactant alkyl amido betaine, the range of HLB value is expanded, the affinity of asphalt is improved, the surface activity is higher, and the shortcomings of a single cold-recycling asphalt emulsifier in emulsifying ability, emulsifying range and emulsion storage stability are overcome; the modified alkali lignin enhances the stereo-hindrance effect and improves the storage stability of the emulsified asphalt; the obtained asphalt emulsifier has higher blending flexibility and good compatibility with most stone; and moreover, the working time of the cold-recycling asphalt mixture can be adjusted, and the requirement on different haul distances in practical construction is met.

The invention provides terminal alkenyl nonsaturated polyether shown in a formula (1), and the invention also provides a purpose of the terminal alkenyl nonsaturated polyether. According to the provided terminal alkenyl nonsaturated polyether, a polyether chain segment can be adjusted through different structural units, so that dispersion effect of a prepared water reducer on concrete is increased, and water-reducing rate of a polycarboxylic acid water reducer and slump constant are obviously increased. The preparation method has the advantages of simple operation, mild condition and easy industrial application.

The invention discloses a wholly aromatic liquid crystal polymer and a preparation method thereof. The wholly aromatic liquid crystal polymer is obtained by the condensation polymerization reaction offour monomers: para-hydroxybenzoic acid, triptycene quinhydrone, terephthalic acid and m-phthalic acid. By introducing a triptycene unit with a space steric effect, the melting temperature of homopolymerizing para-hydroxybenzoic acid is reduced, a nematic liquid crystal polymer with excellent melting processing performance is obtained and the performance of fiber members is good; the triptycene unit is introduced into a rigid chain so as to have double functions of space steric hindrance and a benzene ring substitutional group, thereby increasing the molecule width of the polymer and reducingthe action force among the molecules and a melting point; however, the extension direction of the rigid chain is not changed and therefore, a copolymer still keeps good liquid crystal performance andgood mechanical performance. The thermal melting temperature of the liquid crystal polymer is from 280 DEG C to 370 DEG C and mostly from 290 DEG C to 350 DEG C. The liquid crystal polymer can be widely used for electronic electric appliances and parts and components of other precise equipment.

The invention discloses a preparation method for a solid polycarboxylic acid slump retaining agent. The preparation method for the solid polycarboxylic acid slump retaining agent comprises the steps: (1) adding unsaturated polyoxyethylene ether and cumenyl polyoxyethylene ether to a reaction kettle; heating the unsaturated polyoxyethylene ether and the cumenyl polyoxyethylene ether so that the unsaturated polyoxyethylene ether and the cumenyl polyoxyethylene ether are in a melted state; adding a catalyst to the reaction kettle at one time and uniformly stirring these materials; (2) respectively dripping a first mixed solution and a second mixed solution to a material obtained in the step (1); and (3) after reaction is finished, performing vacuum pumping on the reacted material by using a mechanical pump to remove organic solvent in a material obtained in the step (2); and slicing the material by using a condensing slicer to obtain the white flaky solid polycarboxylate superplasticizer. Under an alkaline condition of a cement, the hydrolysis of a cross-linking structure of the solid polycarboxylate superplasticizer prepared by the preparation method for the solid polycarboxylic acid slump retaining agent is slower than that of a superplasticizer, which is obtained by copolymerizing monomers containing groups such as ester, anhydride and so on; with the prolonging of the time, the cross-linking structure of the solid polycarboxylate superplasticizer is gradually hydrolyzed to continuously release carboxy groups contributive to the water reducing effect, so that the lost water reducing rate is compensated and the solid polycarboxylate superplasticizer has better slump retaining property.

The invention discloses a preparation method of high-performance forward osmosis membrane and relates to a method of membrane modification. The preparation method aims at solving the problem that the salt back-mixing flux of existing sea water desalination forward osmosis membrane is high. The method comprises the following steps: 1, mixing a membrane forming polymer, an addition agent and a solvent to prepare membrane casting liquid, and forming membrane by a phase inversion method; 2, putting the membrane in hot water bath to dip, then putting the membrane in an organic solution to dip, using deionized water to wash, putting the membrane in glycerol aqueous solution to dip, after taking the membrane out, drying the membrane by airing, storing the membrane in a drying tank. According to the preparation method of the high-performance forward osmosis membrane, common chemical reagents are used for preparing a macromolecule permeable membrane material, so that under the condition of keeping water flux not to be reduced (even if the water flux is increased), the salt back-mixing flux is lowered, the selectivity of forward osmosis technology to ions (or molecules) in water is effectively improved, and the preparation method has very important practical significance to the practical application of the forward osmosis technology. Meanwhile, the preparation method has advantages of being simple in process, convenient to operate, low in reagent price and high in repeating utilization rate.

The invention discloses a preparation method for modified magnesium-aluminium hydrotalcite cable fillers and belongs to the technical field of preparation of cable fillers. The preparation method disclosed by the invention has the beneficial effects that firstly a tetraethoxysilane hydrolysis method is utilized for preparing silica sol, and since the silica sol contains silicon dioxide, oxygen inthe air can be effectively isolated from a base material to prevent contact; in addition, bismaleimide resin has heat resistance, and is easily cured on the polyethylene surface to form a triazine-ring structure, so that the compatibility of self-made magnesium-aluminium hydrotalcite with the base material is improved; meanwhile, the self-made magnesium-aluminium hydrotalcite particles are uniformly dispersed on the surface of the base material, so that the surface temperature of the base material is reduced and the flame-retardant effect is achieved; furthermore, in the heat-absorbing and decomposing process of the self-made magnesium-aluminium hydrotalcite, an alkali porous composite oxide is obtained, and can be combined with a carbonized product on the surface of the base material to form a protective film, so that the invasion of heat and oxygen can be effectively prevented, the flame retardance of the cable fillers can be further improved and the application prospect is wide.