37results about How to "Applicable to a wide molecular weight range" patented technology

The invention relates to a preparation method of a star polycarboxylic acid high-performance water reducing agent. Polybasic alcohol and (methyl) acrylic acid used as main raw materials for esterification are esterified and polymerized to prepare the star polycarboxylic acid high-performance water reducing agent material: the (methyl) acrylic acid and polybasic alcohol used as reactants are esterified under the action of a catalyst to firstly prepare a star polymerizable active terminal, and free-radical polymerization reaction is carried out with unsaturated polyethenoxy ether, molecular weight regulator and unsaturated carboxylic acid monomer under the action of an initiator to prepare the star polycarboxylic acid high-performance water reducing agent. The invention is easy to control, and has the advantages of high polymerization degree, low cost and no pollution; the esterification reaction is carried out form an active core, and the free-radical polymerization is carried out to generate the chain arm, thereby implementing the polycarboxylic acid high-performance water reducing agent in a star molecular structure; and under the condition of common doping amount and low doping amount, the star polycarboxylic acid high-performance water reducing agent has better cement paste flowability and holding capacity than the traditional linear and comb polycarboxylic acid water reducing agents, and has favorable cement adaptability and concrete application performance.

The invention discloses a preparation method of a polyester type pure solid polycarboxylic acid high-performance water reducing agent, belonging to the field of water reducing agents. According to the invention, by taking a (methyl) acrylic acid monomer and a polyethylene glycol compound as reactants, a polymerizable macromonomer is prepared through esterification reaction under the effect of a catalyst, and the polymerizable macromonomer conducts a free radical bulk polymerization reaction with an unsaturated carboxylic acid monomer and a chain transfer agent under the effect of an initiator in an environment without any solvent to obtain the polyester type pure solid polycarboxylic acid high-performance water reducing agent. The method disclosed by the invention has strong process controllability, high degree of polymerization and low cost and prevents environmental pollution; a completely anhydrous polyester type pure solid polycarboxylic acid high-performance water reducing agent is prepared through esterification reaction and bulk polymerization, which has neat cement paste liquidity and holding ability, cement adaptability and concrete application performance similar to a traditional solution method; meanwhile, since the polymer product is an anhydrous pure solid, a solution with any concentration can be prepared according to actual needs; and without the after-treatment processes such as heating and drying, solvent separation and the like, the transportation is more convenient, and good market competitiveness and application prospects are realized.

The invention relates to a reduced-type polycarboxylic acid water reducer and a preparation method thereof. An esterification method is employed for synthesizing a reduced monomer having a low surfacetension, and the reduced polycarboxylic acid water reducer is prepared through polymerization; acid anhydride or unsaturated carboxylic acid and ethers molecules are subjected to an esterification reaction to prepare the reduced monomer under effect of a catalyst, and then the reduced monomer, nonsaturated polyoxyethylene ether, unsaturated carboxylic acid or a mixture of unsaturated carboxylic acid or its acid anhydride, and a molecular weight conditioning agent are subjected to a free radical copolymerization reaction under effect of an initiator. The method has the advantages of easy control, high yield, low cost, environmental protection, and no pollution. During a polymerization process, a reduced group is introduced, so that the water reducer has low surface tension, an anchoring group is introduced, has good cement slurry-cleaning fluidity under common doping, reduces the surface tension force of a cement aperture solution, and reduces evaporation rate of the solution so as toeffectively reduce the mortar contraction. The obtained water reducer presents good water-reducing and reduction characteristic.

The invention relates to a preparation method for synthesizing a high-performance polycarboxylic acid water reducing agent by undergoing a one-step amidation reaction, belonging to the field of water reducing agents. In the invention, a high-performance polycarboxylic acid water reducing agent material is prepared by directly reacting with a one-step amidation method, i.e., the water reducing agent is obtained by undergoing an amidation reaction on reactants which are respectively polymethacrylic acid and methoxyl polyethenoxy ether containing amino at the other end under the action of a catalyst. The method has the advantages of conveniently-controlled process, easiness, practicability, low cost and environmental friendliness. An amide structure and a polyethenoxy ether structure are introduced into the molecular structure of the polycarboxylic acid water reducing agent by undergoing a one-step amidation reaction, so that high flow property of cement is realized, the flow property keeping ability and the cement adaptability are remarkably enhanced, and high flowability can be achieved under the conditions of low cement water factor and low mix proportion.

The invention discloses a preparation method for a cationic side chain esterified-grafted highly-mud-resistant cement dispersing agent, and belongs to the field of dispersing agents. The preparation method comprises the following steps: performing free radical polymerization on an unsaturated carboxylic acid monomer serving as a reactant to obtain a polycarboxylic acid main chain under the action of an initiator and a chain transfer agent, performing free radical polymerization on an unsaturated cationic quaternary ammonium salt monomer serving as a reactant to obtain a hydroxyl-terminated cationic side chain under an oxidization-reduction initiation system formed by high-valence ceric salt and alcohol, and performing esterification-grafting reaction on the polycarboxylic acid main chain, the hydroxyl-terminated cationic side chain and a polyethylene glycol compound in the presence of a catalyst. According to the preparation method, a process is simple and easy to control, and the preparation method is low in cost, energy-saving, efficient, environment-friendly and free of pollution; a composite side chain structure is modified and synthesized by a molecular structure design, so that side chain steric hindrance effects are successfully achieved, cationic charge arrangement is successfully implemented, water reduction and slump retaining characteristics and clay side effect suppression capabilities higher than those of an ordinary polycarboxylic acid water reducing agent are achieved, and the dispersing agent has broad market prospect and great popularization and application potential.

Belonging to the field of dispersants, the invention provides a method for preparation of high mud resistant polycarboxylic acid dispersant by unsaturated halogenated hydrocarbon copolymerization and grafting with a cationic side chain. The method consists of: employing an unsaturated carboxylic acid monomer, an unsaturated halogenated hydrocarbon monomer, an unsaturated cationic quaternary ammonium salt monomer, a polyethylene glycol compound and the like as the raw materials, firstly conducting main chain copolymerization, then polymerizing the cationic side chain, performing functionalization, and finally carrying out etherification grafting so as to synthesize the excellent performance high mud resistant polycarboxylic acid dispersant material with unsaturated halogenated hydrocarbon copolymerized and grafted with cationic side chain, i.e. taking unsaturated carboxylic acid and unsaturated halogenated hydrocarbon as the reactants, conducting free radical polymerization to obtain a carboxylic acid-halogenated hydrocarbon copolymer main chain, using high valence cerium salt-alcohol to initiate polymerization of an unsaturated cationic quaternary ammonium salt monomer so as to obtain a hydroxyl terminated cationic side chain, then modifying the hydroxyl terminated cationic side chain and the polyethylene glycol compound to obtain a functionalized side chain, and carrying out etherification grafting of the functionalized side chain on the carboxylic acid-halogenated hydrocarbon copolymer main chain. The method provided by the invention realizes high water reduction, slump loss resistance, high clay resistance and other multiple effects.

The invention discloses a polycarboxylate high-efficiency water reducer and a preparation method thereof. The preparation method comprises the following steps of at normal temperature, dropwise adding components B, C into a component A, cooling to room temperature after dropwise adding the components, and adjusting the pH value to obtain the polycarboxylate high-efficiency water reducer, wherein the component A is obtained by mixing and stirring polyoxyethylene ether, polyethylene glycol and water and then adding a tin or acid catalyst and hydrogen peroxide; the component B is obtained by mixing acrylic acid, a reducing agent and water; and the component C is obtained by mixing sodium methallyl sulfonate, an initiator and water. The water reducer disclosed by the invention is of a multi-arm branch structure with sufficient arm lengths, so that a steric-hinerance effect can be sufficiently developed, the water reduction performance is high, and the working performance of concrete is improved; and the method disclosed by the invention is mild in reaction condition, simple in technology, few in side reactions, safe, environmentally-friendly, low in energy consumption and low in production cost.

The invention relates to a method for preparing a polycarboxylate superplasticizer with a main chain modified isocyanate grafted positive ion side chain and belongs to the field of the superplasticizer. The method comprises the following steps: by taking unsaturated carboxylic acid and unsaturated amide monomer as reactants, acquiring a polycarboxylic acid-amide main chain through free radical polymerization; further modifying the amide group on the main chain as isocyanate group; by taking unsaturated positive ion quaternary ammonium salt monomer as the reactant, performing free radical polymerization under an oxidation-reduction initiating system composed of high-price cerate and alcohol, thereby acquiring an end hydroxy positive ion side chain; performing grafting reaction on polycarboxylic acid main chain containing isocyanate with the end hydroxy positive ion side chain and the polyethylene glycol compound. The method has the advantages of simple and controllable process, low cost, energy-saving effect, high efficiency, polyethylene glycol and no pollution; the main chain modified isocyanate is grafted with the positive ion side chain and the polyether side chain according to a molecular structure design method; the double modification for main chain and side chain of molecule is successfully realized; the water-reducing collapse-protecting property and the capacity of restraining clay side effect are better than those of the common polycarboxylate superplasticizer.

The invention relates to a method for preparing pH-responsive comb-structure polycarboxylic acid through terminal group functionalization. According to the method, with a pH-responsive monomer, unsaturated halogenated hydrocarbon, a small carboxylic acid momonomer and the like as raw materials, a polycarboxylate material is prepared through self-polymerization first, then substitution and then copolymerization; namely, with the pH-responsive monomer as a reactant, a terminal group-functionalized pH-responsive polymer chain is produced through the self-polymerization under the actions of an initiator and a terminal group functionalizing agent, then a substitution reaction is performed on the terminal group-functionalized pH-responsive polymer chain and the unsaturated halogenated hydrocarbon to obtain a pH-responsive macromonomer, and finally a copolymerization reaction is performed on the pH-responsive macromonomer and the small carboxylic acid momonomer under the action of the initiator to obtain a comb-structure polymer which uses polycarboxylic acid as a main chain and has a side chain with a pH-responsive function. By the method, the process is high-efficiency and energy-saving, the conversion rate of a product is high, the functional modification of the polycarboxylic acid is successfully achieved through introduction of the pH-responsive polymer side chain by a terminal group functionalization method, an excellent characteristic of inhibiting shrinkage of cement mortar is shown, and the market competitiveness and the application prospect are very good.

A method for preparing a macro-monomer synthesized polycarboxylate water reducer through alcoholysis of alkenyl-acyl chloride belongs to the field of water reducers. The method comprises the following steps: firstly polymerizing a cationic chain, and then reacting with the alkenyl-acyl chloride, thus obtaining a macro-monomer; then carrying out copolymerization on the macro-monomer and a carboxylic acid micro-monomer, i.e., polymerizing under an oxidization-reduction initiating system formed by high-valence cerate and alcohols by taking an unsaturated cationic quaternary ammonium salt monomer as a reactant, thus obtaining a terminal hydroxyl cationic long chain; then respectively enabling the terminal hydroxyl cationic long chain and polyethylene glycol monomothyl ether to react with the alkenyl-acyl chloride respectively, thus preparing macro-monomers with different structures; then carrying out free radical polymerization on the macro-monomers and unsaturated carboxylic acid micro-monomers, thus obtaining the macro-monomer composite polycarboxylate water reducer. According to the method disclosed by the invention, the macro-monomers with different structures and functions are successfully synthesized through ways of polymerizing the cationic chain and respectively reacting with the alkenyl-acyl chloride by combining polyether, and a novel comb-structure polycarboxylate water reducer which takes a polycarboxyl acid as a main chain and the cationic long chain and the polyether as polybasic side chains can be finally obtained. A reaction technology is simple and easy, and multiple excellent effects of retaining slump through reducing water, resisting clay, and the like are realized.

The invention discloses a method for preparing a concrete water reducer with styrene sulfonate as monomers, and belongs to the field of water reducers. The method includes the steps that firstly, styrene sulfonate and unsaturated carboxylic acid monomers are subjected to free radical copolymerization to obtain a polycarboxylic acid-styrene sulfonate main chain, and then benzene sulfonate on the main chain is modified into phenylsulfonyl halide groups; then, an oxidation-reduction initiating system is formed by high-valence cerate and alcohol to initiate polymerization of unsaturated cationic quaternary ammonium monomers to obtain a hydroxyl-terminated cationic long chain; then, the polycarboxylic acid main chain containing the phenylsulfonyl halide groups, the hydroxyl-terminated cationic long chain and a polyethylene glycol compound are subjected to sulfonylation to obtain the concrete water reducer. According to the method, based on the molecular structure design principle, by modifying styrene sulfonate into phenylsulfonyl halide and carrying out sulfonylation on grafted cationic side chains and polyethylene glycol side chains, the novel concrete water reducer containing a double-side-chain structure is successfully synthesized; the reaction process is mild, easy to control, capable of saving energy and efficient, and the concrete water reducer shows multiple excellent effects of water reduction for slump loss resistance, clay resistance and the like.