58results about How to "High double bond retention" patented technology

The invention discloses slow-release collapse-preventing type polycarboxylic water reducing agent and a preparation method thereof, and belongs to the field of preparation of the water reducing agent. The slow-release collapse-preventing type polycarboxylic water reducing agent consists of methyl allyl polyoxyethylene ether, acrylic acid, methyl acrylic polyethylene glycol monoester, imide, initiator, vitamin C, chain transfer agent and deionized water. The preparation method comprises the following steps of: preparing macromonomer methyl allyl polyoxyethylene ether, acrylic acid, methyl acrylic polyethylene glycol monoester, imide and vitamin C; under the action of the polymerization initiator and the chain transfer agent, dissolving the methyl allyl polyoxyethylene ether into deionized water, rising temperature to 40 DEG C for dissolving, adding the initiator, then respectively dripping water solution A prepared by dissolving the chain transfer agent, the acrylic acid, the methyl acrylic polyethylene glycol monoester and the imide in the deionized water and V.C water solution B, and after the dripping is finished, carrying out insulation, cooling and neutralization to obtain a finished product. The slow-release collapse-preventing type polycarboxylic water reducing agent disclosed by the invention has the advantages that the loss and the evaporation of water in concrete due to long-time transportation and higher temperature are effectively prevented, and the difficulty of excessively-fast slump loss of the concrete in engineering is solved.

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 relates to a synthesis method of 4- hydroxybutyl vinyl ether polyoxyethylene ether, and belongs to the technical field of polyether compound synthesis in organic chemistry. The synthesis method comprises two phases, namely a primary synthesis phase and a final synthesis phase, and specifically comprises the following steps: subjecting a part of 4-hydroxybutyl vinyl ether to a pre-reaction with a primary synthesis catalyst, adding the pre-reaction product into the rest part of 4-hydroxybutyl vinyl ether, introducing ethylene oxide to carry out primary synthesis so as to obtain a primary product, adding a final synthesis catalyst into a part of the primary product to carry out a secondary pre-reaction, and subjecting the secondary pre-reaction product to final synthesis reactions with the rest part of the primary product and ethylene oxide so as to obtain the final product. The product obtained by the technical scheme provided by the invention has the advantages of low by-product content, narrow molecular weight distribution, and high double-bond protection rate.

The invention discloses a low-sensitivity anti-mud polycarboxylic acid water reducing agent and a preparation method thereof. The pH value is 6.0-6.5, and the solid content is 45-55%. The water reducing agent is composed of the following components in parts by weight: 90-130 parts of 4-hydroxybutylvinyl polyoxyvinyl ether with the molecular weight of 2000-5000, 6-10 parts of unsaturated monocarboxylic acid, 3-6 parts of unsaturated carboxylate monomer, 1-5 parts of unsaturated amphoteric quaternary alkylphosphonium salt, 0.2-0.8 part of oxidizer, 0.2-1.0 part of reducer, 0.02-0.06 part of catalyst, 0.2-0.6 part of chain-transfer agent, a right amount of potassium hydroxide water solution, a right amount of sodium hydroxide water solution and a right amount of deionized water. The polycarboxylic acid water reducing agent has the advantages of more uniform side chain distribution and favorable slump retaining effect, and has excellent low sensitivity to the doping amount changes.

The invention relates to methylallyl alcohol random polyether and a preparation method thereof, and belongs to polyether compound synthesis in organic chemistry. The method comprises the following steps: firstly, ensuring methylallyl alcohol with the prescription dosage being 5 to 20 percent to be reacted with a catalyst I, putting the methylallyl alcohol into the rest methylallyl alcohol, leading ethylene oxide and propene oxide mixed according to a specific ration into the methylallyl alcohol, and obtaining methylallyl alcohol random polyether low polymer with the molecular weight being 400 to 1000 after reaction; secondly, enabling 5 to 20 percent of methylallyl alcohol random polyether low polymer obtained in the first step to be reacted with a catalyst II, putting the methylallyl alcohol random polyether low polymer into the rest methylallyl alcohol random polyether low polymer, feeding ethylene oxide and propene oxide mixed according to a specific ration into the methylallyl alcohol random polyether low polymer, and obtaining methylallyl alcohol random polyether with the molecular weight being M after reaction. The methylallyl alcohol random polyether is applied to the synthesis of a polycarboxylate superplasticizer to be applied to a concrete additive, and has the advantages of good cement dispersity and good solubility with other compounds.

The invention relates to a polycarboxylate water reducer and specifically relates to a preparation method of polycarboxylate water reducer macromonomer methallyl alcohol polyoxyethylene ether. The method comprises the following steps: performing condensation reaction with ethylene oxide by taking lithium aluminum tetrahydride as a catalyst and taking an intermediate product obtained by reaction of methallyl alcohol and lithium aluminum tetrahydride and methallyl alcohol as raw materials to obtain a methallyl alcohol oligomer, further enabling the methallyl alcohol oligomer to perform condensation reaction with the added ethylene oxide under the action of an alkaline catalyst, terminating with propylene oxide, and adding glacial acetic acid to neutralize to obtain methallyl alcohol polyoxyethylene ether. The preparation method provided by the invention has the advantages of simple process, safety, low reaction temperature, short reaction time and low production cost; and obtained methallyl alcohol polyoxyethylene ether has narrow distribution of relative molecular weight and high retention rate of double bonds.

The invention discloses double-branch allylamine polyethenoxy ether and a synthetic method thereof. The double-branch allylamine polyethenoxy ether is synthesized from the following raw materials in mole ratio through two steps: allylamine and epoxyethane in a mole ratio of 1:(4-100), and a catalyst which accounts for 0.08-0.2% of the total mass of allylamine and epoxyethane. The double-branch allylamine polyethenoxy ether obtained by the method disclosed by the invention is high in double-bond retention rate under a reaction condition, and can be directly applied to synthesis of a polycarboxylate superplasticizer; and a two-step method is adopted, and a water removal step is increased, so that the content of a reaction byproduct namely polyethylene glycol is reduced.

A highly-adaptive ultra-slow-release type polycarboxylate slump retaining admixture and a preparation method thereof are disclosed. The method includes an esterification step, namely a step of reacting methacrylic acid, a saturated acid and 3-bis(2-hydroxyethyl)amino-2-hydroxy propanesulfonic acid under the existence of a catalyst to obtain an unsaturated esterified small monomer; (2) subjecting 4-butanediol vinyl ether polyoxyethylene ether as a macromonomer to copolymerization under the action of a composite photoinitiator; and (3) neutralizing the obtained copolymerization product with a sodium hydroxide solution to obtain the slump retaining admixture. The prepared slump retaining admixture has good slump retaining capability at high temperature for long time, has certain anti-mud effects and has good adaptability to mud-containing ground materials.

The invention discloses a reactive emulsifier for emulsion polymerization, a preparation method and application thereof. The reactive emulsifier includes the compound(s) shown as formula (I) and/or formula (II) in the specification. The preparation method includes: carrying out ring-opening reaction on fatty primary amine and a glycidyl ether compound with unsaturated double bond, then conducting alkoxylation on the product to obtain a nonionic reactive emulsifier with a reactive double bond and an anionic reactive emulsifier derived therefrom. The emulsifier provided by the invention employs the reaction of primary amino and the glycidyl ether compound to introduce the double bond, the reaction activity and selectivity are stronger, and the reaction conditions are milder, the double bond loss in the reaction can be reduced, and the reactive double bond content of the final emulsifier product can be increased. In the process of emulsion polymerization, the emulsifier has higher reactivity with monomers, and can improve the water resistance of emulsion products more effectively.

The invention provides a macromer for preparing polycarboxylic acid water-reducer and a preparation method thereof. The macromer is synthesized by the reaction of 2-(vinyloxy)ethanol and epoxyethane as main materials. The macromer has simple molecular structure, the production process is safe and steady, and the cost is low; the reactivity is high and the conditions is easily controlled when the macromer is used for preparing polycarboxylic acid water-reducer, the obtained polycarboxylic acid water-reducer has high performance and performance and price ratio.

The invention relates to a polycarboxylic acid water reducer, and concretely relates to a preparation method of a polycarboxylic acid water reducer macromonomer ethylene glycol monovinyl polyoxyethylene ether. The method comprises the following steps: reacting ethylene glycol monovinyl ether with lithium aluminum hydride to obtain a catalyst, carrying out a condensation reaction on the ethylene glycol monovinyl ether and ethylene oxide under the action of the catalyst to obtain an ethylene glycol monovinyl ether oligomer, carrying out a condensation reaction on the ethylene glycol monovinyl ether oligomer and ethylene oxide under the action of an alkaline catalyst, performing termination with epoxypropane, and adding glacial acetic acid to neutralize in order to obtain the ethylene glycolmonovinyl polyoxyethylene ether. The ethylene glycol monovinyl polyoxyethylene ether obtained in the invention has the advantages of narrow relative molecular weight distribution, high double-bond reservation rate, simple process, safety, low reaction temperature, short reaction time and low production cost.

The invention discloses a preparation method for methyl alkenyl polyoxyethylene polyoxypropylene ether with high polymerization degree and macromonomer. The preparation method includes the following steps: 1) utilizing methyl alkenyl alcohol as a starting agent, adding ethylene oxide in the presence of a basic catalyst to carry out a condensation reaction, and performing curing at a maintained temperature after full introduction to obtain a methyl alkenyl alcohol polyoxyethylene ether oligomer; 2) adding the basic catalyst to the oligomer obtained in the step 1), adding propylene oxide for performing the condensation reaction, and performing the curing at the maintained temperature after the full introduction; and 3) continuing to introduce the ethylene oxide in a reactor for performing the condensation reaction until no pressure in the reactor, and then adding acetic acids for performing neutralization to obtain methyl alkenyl alcohol polyoxyethylene polyoxypropylene ether. Synthesisof the methyl alkenyl polyoxyethylene polyoxypropylene ether with the high degree of polymerization and the macromonomer is performed in two steps, the mass growth ratio is up to 1:100, a product is high in degree of polymerization and is high in reactivity, and a synthetic polycarboxylate-type water reducing agent is excellent in slump loss resistant property and comprehensive performance.

The present invention provides a hydrogenated reactive emulsifier with excellent stability and water resistance, and a preparation method and application thereof, the side chain of hydrogenated cardanol or hydrogenated cardanol polyether contains no double bonds, and the reactivity is mild. The reactive emulsifier is a compound comprising the structure shown as a formula (I) in the description. The hydrogenated reactive emulsifier with excellent stability and water resistance provided by the invention can react with polymerized monomers more effectively, so that an obtained polymer emulsion has excellent stability and film-forming and water resistance.

The invention relates to the technical field of concrete admixtures, and in particular, relates to preparation methods of a polyether monomer and a polycarboxylate water reducer. The polyether monomeris prepared by the following method: 1) in the presence of a basic catalyst, reacting an unsaturated compound with at least one active hydrogen atom with alkylene oxide to obtain an alkoxylation product I; and 2) in the presence of a basic catalyst, reacting the alkoxylation product I with alkylene oxide to obtain an alkoxylation product II, wherein the reaction temperature of the alkoxylation product I and alkylene oxide in the step 2) is 25 DEG C or above. The polyether monomer prepared by the method disclosed by the invention has good polymerization activity and high double bond retentionrate, has lower synthesis temperature than common polyether monomers, can be stored and used for a long time without neutralization, and simplifies the synthesis process steps of the polyether monomer.