Preparation method for solid polycarboxylic acid slump retaining agent

Abstract

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.

Description

technical field

[0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of a solid polycarboxylic acid slump-retaining agent. Background technique

[0002] As the fifth component of modern concrete, polycarboxylate superplasticizer has been widely used in the field of concrete engineering technology due to its excellent low dosage, high slump retention, and large degree of freedom in molecular design. At present, most widely used polycarboxylate superplasticizers are solution products with a concentration of 10-50%. Due to the remote distance of some construction sites, the lower solid content will increase the transportation cost; in addition, the wide application of dry powder mortar also puts forward an urgent demand for the production and application of solid polycarboxylate water reducer. At present, most of the powder polycarboxylate water-reducers on the market are obtained by spray drying, but whe...

Examples

Embodiment 1

[0027] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0028] (1) Add isopentenyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, raise the temperature to 60°C, make it in a molten state, and then add N,N-dimethylaniline at one time , and stir evenly;

[0029] (2) Add dropwise the first mixed solution consisting of acrylic acid, γ-(meth)acryloyloxypropyl trimethoxysilane and triallyl phosphate and The second mixed solution composed of dimethyl azodiisobutyrate, 3,6-dioxo-1,8-octanedithiol and acetone is dropped within 3 hours, and the reaction is continued for 1 hour;

[0030] (3) After the reaction, use a mechanical pump to evacuate for 10 minutes, the vacuum pressure is 0.01-0.05MPa, remove the acetone in the material obtained in step (2), and then use a condensing microtome to slice it to obtain white flake solid polycarboxylate Acid slump retaining agent, and packed by pac...

Embodiment 2

[0033] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0034] (1) Add methallyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, and raise the temperature to 80°C. C, making it in a molten state, then adding N,N-diethylaniline in one go, and stirring evenly;

[0035] (2) To the material obtained in step (1), add dropwise the first compound composed of acrylic acid, γ-(meth)acryloyloxypropyltriethoxysilane and bistrimethylsilylated vinyl phosphate. The first mixed solution and the second mixed solution composed of cumene hydroperoxide, 3,6-dioxo-1,8-octanedithiol and n-hexane are dripped within 3 hours, and the reaction is continued for 1 hour;

[0036] (3) After the reaction is over, use a mechanical pump to vacuumize for 10 minutes, and the vacuum pressure is 0.01 to 0.05 MPa to remove the n-hexane in the material obtained in step (2), and then use a condensing microtome to sli...

Embodiment 3

[0039] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0040] (1) Add methallyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, raise the temperature to 60°C, make it in a molten state, and then add N,N-diethyl aniline, and stir well;

[0041] (2) Add dropwise the first mixed solution consisting of acrylic acid, γ-(meth)acryloyloxypropyl triethoxysilane and 6 triallyl phosphate respectively in the material obtained in step (1) and The second mixed solution composed of dicyclohexyl peroxydicarbonate, 3,6-dioxo-1,8-octanedithiol, and carbon tetrachloride was dropped within 4 hours, and the reaction was continued for 1 hour;

[0042] (3) After the reaction finishes, adopt mechanical pump to vacuumize 10min, and vacuum pressure is 0.01~0.05MPa, removes the carbon tetrachloride in the material gained in step (2), adopts condensing microtome to slice then, promptly obtains the white ...

technical field

[0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of a solid polycarboxylic acid slump-retaining agent. Background technique

[0002] As the fifth component of modern concrete, polycarboxylate superplasticizer has been widely used in the field of concrete engineering technology due to its excellent low dosage, high slump retention, and large degree of freedom in molecular design. At present, most widely used polycarboxylate superplasticizers are solution products with a concentration of 10-50%. Due to the remote distance of some construction sites, the lower solid content will increase the transportation cost; in addition, the wide application of dry powder mortar also puts forward an urgent demand for the production and application of solid polycarboxylate water reducer. At present, most of the powder polycarboxylate water-reducers on the market are obtained by spray drying, but whe...

Examples

Embodiment 1

[0027] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0028] (1) Add isopentenyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, raise the temperature to 60°C, make it in a molten state, and then add N,N-dimethylaniline at one time , and stir evenly;

[0029] (2) Add dropwise the first mixed solution consisting of acrylic acid, γ-(meth)acryloyloxypropyl trimethoxysilane and triallyl phosphate and The second mixed solution composed of dimethyl azodiisobutyrate, 3,6-dioxo-1,8-octanedithiol and acetone is dropped within 3 hours, and the reaction is continued for 1 hour;

[0030] (3) After the reaction, use a mechanical pump to evacuate for 10 minutes, the vacuum pressure is 0.01-0.05MPa, remove the acetone in the material obtained in step (2), and then use a condensing microtome to slice it to obtain white flake solid polycarboxylate Acid slump retaining agent, and packed by pac...

Embodiment 2

[0033] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0034] (1) Add methallyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, and raise the temperature to 80°C. C, making it in a molten state, then adding N,N-diethylaniline in one go, and stirring evenly;

[0035] (2) To the material obtained in step (1), add dropwise the first compound composed of acrylic acid, γ-(meth)acryloyloxypropyltriethoxysilane and bistrimethylsilylated vinyl phosphate. The first mixed solution and the second mixed solution composed of cumene hydroperoxide, 3,6-dioxo-1,8-octanedithiol and n-hexane are dripped within 3 hours, and the reaction is continued for 1 hour;

[0036] (3) After the reaction is over, use a mechanical pump to vacuumize for 10 minutes, and the vacuum pressure is 0.01 to 0.05 MPa to remove the n-hexane in the material obtained in step (2), and then use a condensing microtome to sli...

Embodiment 3

[0039] A solid polycarboxylate slump-retaining agent and a preparation method thereof, comprising the following steps:

[0040] (1) Add methallyl polyoxyethylene ether and cumenyl polyoxyethylene ether into the reaction kettle, raise the temperature to 60°C, make it in a molten state, and then add N,N-diethyl aniline, and stir well;

[0041] (2) Add dropwise the first mixed solution consisting of acrylic acid, γ-(meth)acryloyloxypropyl triethoxysilane and 6 triallyl phosphate respectively in the material obtained in step (1) and The second mixed solution composed of dicyclohexyl peroxydicarbonate, 3,6-dioxo-1,8-octanedithiol, and carbon tetrachloride was dropped within 4 hours, and the reaction was continued for 1 hour;

[0042] (3) After the reaction finishes, adopt mechanical pump to vacuumize 10min, and vacuum pressure is 0.01~0.05MPa, removes the carbon tetrachloride in the material gained in step (2), adopts condensing microtome to slice then, promptly obtains the white ...

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