阅读说明：本技术 一种水泥减水剂及其制备方法 (Cement water reducing agent and preparation method thereof ) 是由 刘品 张桂 于 2019-11-25 设计创作，主要内容包括：本发明公开了一种水泥减水剂,该水泥减水剂利用甲基烯丙基聚氧乙烯醚、糖蜜、甲基丙烯酸、丙烯酰氯、三乙胺、环氧乙醇、3-巯基丙酸、去离子水、双氧水作为原料制备,制备时先将甲基烯丙基聚氧乙烯醚、环氧乙醇、3-巯基丙酸、去离子水、双氧水加入容器中搅拌,并在搅拌完成后降温保持,同时,将甲基丙烯酸与糖蜜用N,N-二甲基乙酰胺溶解,在三乙胺存在的情况下冰水浴,同时将丙烯酰氯溶解后加入冰水浴完成后的混合溶液中,过滤后除溶剂并再次加入N,N-二甲基乙酰胺中与混合物溶液混合搅拌,调整pH值后得到减水剂。本发明制备的水泥减水剂稳定性好、易于保存,具有良好的缓凝减水效果,且对水泥的分散和保持性能有很大提升。(The invention discloses a cement water reducing agent, which is prepared by using methyl allyl polyoxyethylene ether, molasses, methacrylic acid, acryloyl chloride, triethylamine, epoxy ethanol, 3-mercaptopropionic acid, deionized water and hydrogen peroxide as raw materials. The cement water reducing agent prepared by the invention has good stability, is easy to store, has good retarding and water reducing effects, and greatly improves the dispersion and retention performances of cement.)

1. A cement water reducing agent comprises the following raw materials in parts by mass:

30-50 parts of methyl allyl polyoxyethylene ether

20-30 parts of molasses

6-10 parts of methacrylic acid

10-15 parts of acryloyl chloride

6-8 parts of triethylamine

3-5 parts of epoxy ethanol

2-3 parts of 3-mercaptopropionic acid

70-90 parts of deionized water

5-9 parts of hydrogen peroxide.

2. The preparation method of the cement water reducer is characterized in that the cement water reducer is prepared by adopting the raw materials in parts by mass according to claim 1, and the concrete operation steps are as follows:

s1, weighing the methyl allyl polyoxyethylene ether, the epoxy ethanol, the 3-mercaptopropionic acid, the deionized water and the hydrogen peroxide in parts by mass, adding into a container, stirring for 3-4 hours at the temperature of 60-80 ℃, naturally cooling to 30-40 ℃ along with the container, and keeping for 30-40 min;

s2, dissolving methacrylic acid and molasses by using N, N-dimethylacetamide as a solvent, adding triethylamine as an acid-binding agent, and carrying out ice-water bath reaction on a container for 30-40 min; simultaneously dissolving acryloyl chloride by using N, N-dimethylacetamide, adding the dissolved acryloyl chloride into the mixed solution after the ice water bath is finished, standing for 2 hours, shearing at the rotating speed of 900-1100 r/min for 10-15 min, and filtering;

and S3, adding the filtrate in the S2 into N, N-dimethylacetamide, mixing and stirring the mixture with the mixture solution of the S1, filtering, taking the filtrate, and adjusting the pH value to 6.5-7 to obtain the water reducer.

3. The preparation method of the cement water reducer according to claim 2, wherein a catalyst is added to accelerate the reaction rate when an ice-water bath is carried out, and the catalyst is one or a mixture of phosphoric acid and acetic acid.

4. The method for preparing the water reducing agent for cement according to claim 2, wherein the acryloyl chloride is dissolved in N, N-dimethylacetamide, and then slowly added dropwise into the mixed solution after the completion of the ice-water bath by using a constant pressure dropping funnel.

5. The preparation method of the cement water reducer according to claim 2, characterized in that during ice-water bath, the environment of the container is protected by introducing nitrogen.

Technical Field

The invention relates to the technical field of concrete admixtures, in particular to a cement water reducer and a preparation method thereof.

Background

The concrete water reducing agent is one of the most common concrete additives, has the largest using amount and the widest application range, can effectively reduce the mixing water consumption of the concrete, improve the workability and the strength of the concrete and increase the durability of the concrete by adding the water reducing agent under the condition of keeping the slump constant of the concrete, and simultaneously has a dispersing effect on cement particles, can effectively improve the working performance of the concrete and saves the cement.

The water reducing agent goes through the development process from lignosulfonate, naphthalene water reducing agent to polycarboxylic acid water reducing agent, lignosulfonate is the most common water reducing agent and is prepared by taking lignin as a raw material, and the water reducing agent is easy to cause retardation in the stirring process and can introduce a large amount of air to influence the performance of concrete; the naphthalene water reducer is used as a second-generation water reducer, is the water reducer with the largest dosage in China at present, is a product obtained by sulfonating naphthalene with sulfuric acid and then condensing naphthalene with formaldehyde, belongs to an anionic surfactant, and although the naphthalene water reducer also belongs to a high-efficiency water reducer, compared with a polycarboxylic acid water reducer, the naphthalene water reducer has much poorer water reducing and slump retaining performances due to the structural defects of the naphthalene water reducer, and simultaneously can also cause the increase of the alkali content in an additive and the reduction of the durability of concrete, so that the alkali-aggregate reaction phenomenon is caused, and the service life is greatly shortened; the polycarboxylate water reducer is used as a high-performance water reducer and is a surfactant containing a carboxyl graft copolymer, the molecular structure of the polycarboxylate water reducer is in a comb shape, the polycarboxylate water reducer is mainly prepared by an unsaturated monomer through free radical copolymerization under the action of an initiator, the problem of high manufacturing cost generally exists, in the synthesis process, due to the difference of polymerization degrees in the free radical copolymerization, the quality is uneven, the performance is greatly different, meanwhile, the polycarboxylate water reducer is more sensitive to the mud content of aggregate, the mud in the aggregate can adsorb the polycarboxylate water reducer, and along with the increase of the mud content, the water reducing and dispersing capacity of the polycarboxylate water reducer is seriously reduced, the slump retaining effect is poor, and the workability of fresh concrete is greatly reduced.

Disclosure of Invention

The invention aims to provide a cement water reducing agent and a preparation method thereof, and aims to solve the technical defects in the prior art.

The technical problem solved by the invention is realized by adopting the following technical scheme:

a cement water reducing agent comprises the following raw materials in parts by mass:

30-50 parts of methyl allyl polyoxyethylene ether

20-30 parts of molasses

6-10 parts of methacrylic acid

10-15 parts of acryloyl chloride

6-8 parts of triethylamine

3-5 parts of epoxy ethanol

2-3 parts of 3-mercaptopropionic acid

70-90 parts of deionized water

5-9 parts of hydrogen peroxide

A preparation method of a cement water reducing agent comprises the following main production processes:

s1, weighing the methyl allyl polyoxyethylene ether, the epoxy ethanol, the 3-mercaptopropionic acid, the deionized water and the hydrogen peroxide in parts by mass, adding into a container, stirring for 3-4 hours at the temperature of 60-80 ℃, naturally cooling to 30-40 ℃ along with the container, and keeping for 30-40 min;

s2, dissolving methacrylic acid and molasses by using N, N-dimethylacetamide as a solvent, adding triethylamine as an acid-binding agent, and carrying out ice-water bath reaction on a container for 30-40 min; simultaneously dissolving acryloyl chloride by using N, N-dimethylacetamide, adding the dissolved acryloyl chloride into the mixed solution after the ice water bath is finished, standing for 2 hours, shearing at the rotating speed of 900-1100 r/min for 10-15 min, and filtering;

and S3, adding the filtrate in the S2 into N, N-dimethylacetamide, mixing and stirring the mixture with the mixture solution of the S1, filtering, taking the filtrate, and adjusting the pH value to 6.5-7 to obtain the water reducer.

By way of further limitation, a catalyst, which is one or a mixture of two of phosphoric acid and acetic acid, may be added to accelerate the reaction rate when performing the ice-water bath reaction in step S2.

In step S2, the acryloyl chloride is dissolved in N, N-dimethylacetamide, and then slowly added dropwise to the mixed solution after completion of the ice-water bath using a constant pressure dropping funnel.

Further, in step S2, when the ice-water bath is performed, the container environment is protected by introducing nitrogen gas.

Has the advantages that: the water reducing agent is synthesized by adopting the prior art, has wide raw material sources, simple synthesis process, stable performance, good dispersion effect, capability of obviously improving the fluidity and the working degree of concrete, has the advantages of small using amount, high water reducing rate, wide application range and the like, and has stable property, suitability for long-term storage, no toxicity and environmental protection.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

In the following examples, it will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.