34results about How to "Good dispersion retention" patented technology

The invention relates to a method for preparing a slump loss-resistant type polycarboxylic acid water reducer by silanizing a terminal group of amino polyether. The method provided by the invention takes an amino polyether type compound, a silane coupling agent, an unsaturated carboxylic acid type monomer and the like as main reaction raw materials and a polycarboxylic acid water reducer is prepared through firstly hydrolyzing, substituting, then carrying out condensation, and finally copolymerizing; the method comprises the following steps: firstly hydrolyzing by a halogenated silane coupling agent; then taking the silane coupling agent and the amino polyether type compound to be subjected to substitution reaction; carrying out the condensation on a substituted product and a vinyl silane coupling agent hydrolyzed product; taking a condensed product and unsaturated polyoxyethylene ether, a molecular weight regulator and the unsaturated carboxylic acid type monomer to be subjected to free-radical copolymerization reaction under the action of an initiator to prepare the polycarboxylic acid water reducer with a plurality of branched silane modified polyether side chains. The method provided by the invention has the advantages of simple and easy-to-control process, low cost, energy saving and high efficiency, environmental protection and no pollution; dual modification of the side chains of a main chain of a polycarboxylic acid molecule is successfully realized and more excellent water reduction and slump loss resistance performance, which is better than that of a common polycarboxylic acid water reducer, is represented.

The invention provides a polycarboxylic concrete water reducer which is a copolymer formed by copolymerizing monosomic A, B, C, D and E, wherein the weight-average molecular weight of the copolymer is 20000 to 50000; A is allyl polyglycol ether or methyl-allyl-polyglycol ether, of which the weight-average molecular weight is 800 to 4000; B is maleic anhydride; C is acrylic acid or methacrylic acid; D is 2-acrylamide; and E is N, N'-methylene-bis-acrylamide. Taken by molarity part, when A is 1.0, B is 0.4 to 2.0, C is 1.0 to 3.0, D is 0.1 to 1.0, and the ratio between A+B+C+D and E is 100 to (0.5 to 1.8). Compared with the prior art, the invention has the advantages that under the condition of low dosage of the polycarboxylic concrete water reducer, the dispersivity and the retentivity of concrete are also kept favorable, and the gradual loss control of cement paste fluidity of the polycarboxylic concrete water reducer is obviously superior to a general polycarboxylic water reducer.

The invention discloses a microcrystalline waterproofing agent for concrete and an application thereof, belonging to the field of concrete additives. In terms of parts by mass, it includes the following components: 1-5 parts of defoaming agent; 2-4 parts of modified silicon dioxide powder; 7-10 parts of waterproofing agent; 0.5-1.5 parts of water reducing agent. In the present invention, by adding a certain amount of defoamer to the microcrystalline waterproofing agent, microcapillary pores with relatively short length and small diameter are formed in the concrete, and at the same time, the surface of the modified silica powder particles has more hydrophobic Sexual groups further strengthen the defoaming and foam stabilizing effects, and reduce the volume of capillary pores that will be formed during the gas discharge process. The tension of the liquid on the surface of these micro pores can effectively prevent the liquid from entering the micro pores, thereby greatly enhancing the waterproof ability of concrete.

The invention discloses a method for preparing a maleic anhydride high-efficiency water reducer by optimizing microwave radiation by response surface method. It uses allyl polyoxyethylene ether and sodium methacrylate sodium sulfonate as raw materials, stirs and mixes them evenly with water. Heating to the reaction temperature under certain conditions, then adding maleic anhydride and ammonium persulfate at a constant temperature to react for a period of time, using the response surface method to set the variable parameters of the reaction, cooling after the reaction, and adjusting the pH to obtain a maleic anhydride-based high-efficiency water reducer . On the basis of single factor analysis, the present invention uses response surface method to optimize the synthesis process of maleic anhydride superplasticizers, and draws the process conditions that are more suitable for preparing maleic anhydride superplasticizers. The development and popularization provide scientific test basis.

The application relates to the field of concrete admixtures, and specifically discloses a slump-preserving concrete admixture, a preparation method thereof, and a super-slump-preserving concrete. A super-slump concrete admixture, comprising the following raw materials in parts by weight: 10-30 parts of amino-terminated methoxy polyethylene glycol, 15-10 parts of methoxy polyethylene glycol, and 50-80 parts of polymethacrylic acid , 20-40 parts of aliphatic hydroxy acid, its preparation method is: take amino-terminated methoxy polyethylene glycol, methoxy polyethylene glycol, polymethacrylic acid and aliphatic hydroxy acid by weighing formula quantity, stir together mixed, heated to 100-110°C for 2-3 hours, and dried to obtain the ultra-slump concrete admixture, adding the super-slump concrete admixture of the present application to the concrete to obtain commercial concrete, which is transported in a high-temperature environment It still has good slump retention performance.

The invention discloses an anti-cracking and shrinkage-reducing polycarboxylate water reducer and a preparation method thereof. Its weight-average molecular weight (M w ) is 10000~100000, and the structural formula is that the preparation method of the present invention is: (1) use gallic acid as raw material to introduce unsaturated double bond structure on the structure to prepare gallic acid derivative unsaturated small monomer, and then combine it with carbonyl-containing unsaturated monomer Saturated acid and its derivative monomers are subjected to free radical copolymerization to obtain a water reducer prepolymerization product; (2) Introduce a hydrophilic polyether side chain on the gallic acid derivative of the prepolymerization product to prepare a shrinkage reduction type with excellent performance Polycarboxylate superplasticizer. The anti-cracking and shrinkage-reducing polycarboxylate water-reducer prepared by the present invention has good stability and is suitable for storage under various extreme weather conditions; it has good dispersion effect in concrete, excellent shrinkage reduction effect, and is effective against cracking caused by various types of shrinkage. Very noticeable control and mitigation.

The invention discloses a high-performance reinforcing agent for a pile and a preparation method thereof. The reinforcing agent takes unsaturated acid, urea, TPEG (alkylene polyoxyethylene polyoxypropylene ether) and the like as major chemical synthesis raw materials. Amidation and copolymerization processes are performed under certain condition under the actions of a catalyst, an initiator, a chain transfer agent and the like, so that a high polymer with an amphiphathic structure is obtained. Hydrophilic hydroxyl, carboxyl, amide groups and sulfonic groups, a hydrophobic carbon chain and a polyoxyethylene polyoxypropylene ether long chain structure with a certain steric hindrance effect exist in the molecular structure of the reinforcing agent. The reinforcing agent is suitable for preparing concrete for prestressed high-performance concrete (PHC) pipe piles.

The invention relates to a low molecular weight copolymer dispersant and the preparing method thereof, adopting 40%-70mol% monomer a, 30-60mol% monomer b, 0-15mol% unit c and 0-10mol% monomer d, using water as reaction medium, one-off adding in water soluble initiator and monomer mixture, controlling initial reaction temperature and using a large amount of reaction heat produced in the self-accelerating course of polymerication reaction to fast polymerize the monomer mixture and making it. And it can directly act as dispersant for cement, superfine calcium carbonate, plaster, clay, ceramics and other organic powder, especially for cement-base materials, such as concrete, mortar and grout, having excellent dispersivity and good dispersion retention.

The invention discloses a mixed alcohol polyoxyethylene ether water reducer macromonomer and its preparation method and application. The preparation process of the mixed alcohol polyoxyethylene ether water reducer macromonomer is as follows: under nitrogen atmosphere , Potassium hydroxide, sodium catalyst, methallyl alcohol, prenyl alcohol and ethylene oxide are mixed and stirred to react, and the mixed alcohol polyoxyethylene ether intermediate is synthesized, and the mixed alcohol polyoxyethylene ether intermediate is obtained. Then react with ethylene oxide under a nitrogen atmosphere to synthesize the final product mixed alcohol polyoxyethylene ether, which is a macromonomer used to prepare polycarboxylate water reducers. The mixed alcohol polyoxyethylene ether synthesized by the present invention has both the basic molecular skeleton structure of isopentenol and methallyl alcohol. When the mixed alcohol polyoxyethylene ether product is used to prepare polycarboxylate water reducer , Polycarboxylate superplasticizer is applied to cement, it can maintain the water-reducing performance and at the same time have good dispersion retention.

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 the technical field of concrete admixtures, in particular to a cross-linked air-entraining water-reducing agent and a preparation method thereof, wherein the water-reducing agent comprises: a cross-linked air-entraining polymer, the air-entraining polymer Contains polymers or copolymers derived from monomers including air-entraining monomers, vinyl ether macromonomers. By using the cross-linked air-entraining water reducing agent provided by the present invention, air bubbles can be introduced into the concrete and the air bubbles can be stabilized and the dispersion retention of the concrete can be improved. Not only that, the introduction of the micro-cross-linked structure makes the polymer structure more stretched and the hydration film thicker. , has greater steric hindrance and better dispersibility, dispersion retention and better anti-intercalation effect, and has broad market application prospects.

The invention discloses a ternary block macromonomer graft copolymerization high-property polycarboxylic acid water-reducing agent and a preparation method thereof. The preparation method comprises the following steps: dissolving a ternary block polyether macromonomer, a non-block polyether macromonomer and maleic anhydride into deionized water; then continuously stirring at a certain temperature, and respectively adding an initiating agent, a reducing agent and a chain transfer agent; and after the reaction is completed, regulating pH to neutrality to obtain the ternary copolymerization high-property polycarboxylic acid water-reducing agent. The water-reducing agent disclosed by the invention can enable the concrete to achieve higher flowing property under the condition of lower water cement ratio; because epoxy propane contained in the ternary block polyether macromonomer has an agglomeration effect and has high space steric effect, the synthesized polycarboxylic acid system water-reducing agent has more excellent dispersing retentivity, the water-reducing agent has lower air content when being used for the concrete, and the water-reducing agent is a multifunctional and high-adaptability high-property water-reducing agent which integrates water reduction, slump loss resistance and low air entrainment into a whole.