抗黏土型减水剂的制备及其与黏土相互作用机理研究

发布时间：2018-07-04 14:05

本文选题：聚羧酸 + 黏土　；参考：《合肥工业大学》2017年硕士论文

【摘要】：本论文通过对传统的聚羧酸减水剂进行结构改性,制备出了不含聚乙二醇侧链的新型聚羧酸减水剂,提高了其对黏土的抗性。随后研究了黏土对不同高效减水剂的性能影响,并且探讨了不同高效减水剂和黏土的相互作用机理,该项研究有助于理解黏土在混凝土中的确切作用,为进一步的设计出抗黏土型高效减水剂提供了有用依据。在不同高效减水剂和黏土的相互作用机理的基础上,设计出了一种阳离子型抗泥剂并且用于和传统聚羧酸减水剂复配,该混合体系提高了对黏土的抗性,在混凝土骨料中含有黏土时,为传统的聚羧酸减水剂提高对黏土的抗性提供了解决方案。1、一种含有叔胺基团的单体甲基丙烯酸二甲胺乙酯被引入并且和衣康酸,丙烯酸用来合成聚羧酸减水剂。该减水剂被表征并且测试了其在黏土出现时候对水泥的分散性,结果发现其比传统的聚羧酸减水剂具有更好的分散水泥性能。XRD和TOC测试表明该新型聚羧酸减水剂与黏土的作用方式只是为表面的静电作用。而传统的聚羧酸减水剂与黏土的相互作用是通过表面静电吸附以及层间化学吸附两种作用。2、传统的聚羧酸减水剂,不含聚乙二醇侧链的聚羧酸减水剂,缩聚物高效减水剂被用来研究了它们在黏土出现条件下对水泥的分散性能以及它们与黏土之间的相互作用行为。结果发现在黏土出现下,高效减水剂对水泥的分散性能是受高效减水剂本身对水泥的分散能力以及高效减水剂对黏土的敏感性决定的。而高效减水剂对黏土的敏感性得以系统的研究,结果发现其是由自由水和高效减水剂被黏土的吸附量决定的。黏土与不同高效减水剂作用下,其对阳离子的吸附行为得以研究(包括层间和表面)。高效减水剂与黏土的作用机理得以澄清。这项工作对于目的性的设计出抗黏土型高效减水剂具有指导性作用。3、使用阳离子单体甲基丙烯酰氧乙基三甲基氯化铵发生自由基均聚反应制得了阳离子型抗泥剂,该阳离子单体与传统的聚羧酸减水剂进行了复配使用,结果发现阳离子单体的加入降低了传统聚羧酸减水剂对黏土的敏感性。水分和聚羧酸减水剂被黏土的的吸附测试表明,阳离子型抗泥剂是通过降低自由水和聚羧酸减水剂被黏土的吸附而实现降低聚羧酸减水剂对黏土的敏感性的,XRD测试表明阳离子型抗泥剂抑制了聚羧酸减水剂嵌入到黏土的层间。
[Abstract]:In this paper, a new polycarboxylic acid water reducer without the side chain of polyethylene glycol was prepared by modifying the structure of traditional polycarboxylic acid superplasticizer, and the resistance of polycarboxylic acid water reducer to clay was improved. Then the effects of clay on the properties of different superplasticizers are studied, and the interaction mechanism between different superplasticizers and clay is discussed. This study is helpful to understand the exact role of clay in concrete. It provides a useful basis for the further design of clay resistant superplasticizer. On the basis of the interaction mechanism between different superplasticizers and clay, a cationic anti-mud agent was designed and used in combination with traditional polycarboxylic acid water reducer. The mixed system improved the resistance to clay. When clay is contained in concrete aggregate, it provides a solution for traditional polycarboxylic acid superplasticizer to improve its resistance to clay. A monomer containing tertiary amine group, dimethylamine methacrylate, was introduced and itaconic acid was added. Acrylic acid is used to synthesize polycarboxylic acid superplasticizer. The superplasticizer was characterized and tested for its dispersity to cement when the clay appeared. The results show that the new polycarboxylic acid superplasticizer has better dispersion cement properties than traditional polycarboxylic acid superplasticizer. XRD and TOC tests show that the new polycarboxylic acid superplasticizer acts with clay only by electrostatic interaction on the surface. The traditional interaction between polycarboxylic acid superplasticizer and clay is through surface electrostatic adsorption and interlayer chemisorption, traditional polycarboxylic acid water reducer, poly (carboxylic acid) water reducer without side chain of polyethylene glycol. Condensate superplasticizers have been used to study the dispersion of cement and their interaction with clay in the presence of clay. The results show that the dispersibility of the superplasticizer to cement is determined by the dispersion ability of the superplasticizer to cement and the sensitivity of the superplasticizer to the clay. The sensitivity of the superplasticizer to the clay is studied systematically. It is found that the sensitivity of the superplasticizer is determined by the amount of the free water and the superplasticizer being adsorbed by the clay. The adsorption behavior of cations (interlaminar and surface) was studied by clay and different superplasticizers. The mechanism of the interaction between superplasticizer and clay was clarified. This work is instructive for the purposeful design of anti-clay superplasticizer. Using the cationic monomer methacryloxy ethyl trimethylammonium chloride free radical homopolymerization to produce cationic anti-slime agent. The cationic monomer was mixed with traditional polycarboxylic acid water reducer. The results showed that the addition of cationic monomer reduced the sensitivity of traditional polycarboxylic acid superplasticizer to clay. The adsorption tests of water and polycarboxylic acid superplasticizer by clay show that, Cationic anti-mud agent can reduce the sensitivity of polycarboxylic acid water reducer to clay by reducing the adsorption of free water and polycarboxylic acid water reducer by clay. The results of XRD show that cationic anti-mud agent can inhibit the intercalation of polycarboxylic acid water reducer into clay layer.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528.042.2

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