适于快流砂浆的聚羧酸减水剂的制备及应用研究

发布时间：2018-03-14 10:44

  本文选题：聚羧酸减水剂　切入点：改性合成　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文在二元聚羧酸减水剂合成的基础上,分别采用2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、马来酸单甲酯(MMM)进行进一步地改性合成,探讨改性官能团对减水剂性能的影响。同时针对快流砂浆体系俩个主要性能,流动性与抗离析性,通过净浆流动度、砂浆减水率、Marsh筒流空时间以及浆体流变-触变性等一系列测试,定量地对比研究了不同减水剂的流动性及保水性,最终得到一种在快流砂浆体系中适应性较好的聚羧酸减水剂。首先选用氧化-还原引发体系,丙烯酸(AA)和异戊烯醇聚氧乙烯醚(TPEG)为原料,通过单因素试验优化基础型聚羧酸减水剂(P1)制备条件。并在此条件下分别加入第三改性单体AMPS、MMM进行正交合成,制备三元型聚羧酸减水剂,并通过红外及高效液相色谱进行表征分析了合成产物结构及反应率:(1)P1(二元基础型聚羧酸减水剂)最佳合成条件:n(AA):n(TPEG)=4、n(TBHP):n(吊白块)=3、吊白块(还原剂)、TGA(链转移剂)分别占单体总质量的0.3%、0.5%,反应温度25℃。(2)P2(AMPS型聚羧酸减水剂)最佳合成条件:n(AA):n(TPEG)=4、n(TBHP):n(吊白块)=3、n(AMPS):n(TPEG)=1:2,吊白块(还原剂)、TGA(链转移剂)分别占单体总质量的0.3%、0.5%,反应温度25℃。通过红外及高效液相色谱进行表征分析知P2的反应率达到98%。(3)P3(MMM型聚羧酸减水剂)最佳合成条件:n(AA):n(TPEG)=4、n(TBHP):n(吊白块)=3、n(MMM):n(TPEG)=2:1,吊白块(还原剂)、TGA(链转移剂)分别占单体总质量的0.3%、0.7%,反应温度25℃。通过红外及高效液相色谱进行表征分析知P3的反应率达到96%。接下来将上述合成的三种减水剂(P1、P2、P3)与市售的三三减水剂P4、柯帅减水剂P5进行了性能对比。通过流动度、保水性及Marsh筒流空时间三种测试手段相结合,引入流动性指数α*,用公式定量评价了砂浆体系与不同聚羧酸减水剂的流动性问题,其先后顺序为:P2P4P5P3P1。最后对比了不同水灰比下减水剂对砂浆流变-触变性的影响,得到掺不同聚羧酸减水剂的浆体平均触变面积关系为:P2P4P1P5P3。掺P2减水剂砂浆触变面积最大,这可能是由于P2的加入后,上升阶段浆体絮凝结构较多,阻力较大,在相同转速时转矩较大。下降阶段,部分絮凝结构被破坏,浆体中存在自由颗粒,阻力较小。下降阶段达到与上升阶段相同的转矩所需要的转速更大,从而浆体触变性最大而分散性最好。最终综合上述一系列测试的结果知AMPS型聚羧酸减水剂P2是这五种减水剂中适于快流砂浆体系最优的。
[Abstract]:In this paper, based on the synthesis of binary polycarboxylic acid superplasticizer, 2-acrylamido-2-methylpropanesulfonic acid (AMPSX) and monomethyl maleate (MMM) were further modified and synthesized. The effect of modified functional groups on the properties of superplasticizer was discussed. A series of tests, such as water reducing rate of mortar and Marsh cylinder flow empty time and rheology and thixotropy of mortar, were used to study quantitatively the fluidity and water retention of different water reducers. Finally, a polycarboxylic acid water reducer with good adaptability in the rapid flow mortar system was obtained. Firstly, the redox initiator system, acrylic acid (AA) and isopentenol polyoxyethylene ether (TPEG) were used as raw materials. The preparation conditions of basic polycarboxylic acid superplasticizer (P1) were optimized by single factor experiment. The ternary polycarboxylic acid superplasticizer was prepared by orthogonal synthesis with the addition of the third modified monomer AMPS- MMM under these conditions. The structure and reaction rate of the synthesized product were characterized by IR and high performance liquid chromatography (HPLC). The optimum conditions for the synthesis of the synthesized product were as follows: 1: 1: 1 (binary basic polycarboxylic acid superplasticizer). The optimum conditions for the synthesis of the product were as follows: (1: 1). The optimum conditions for the synthesis of the product were as follows: (1) the ratio of TBHP1 to TBHP1 (TBHP0. 3) and the proportion of TGA (chain transfer agent) to 1% (TGA), respectively. The optimum conditions for synthesis of 0.33% of total body mass, reaction temperature 25 鈩，

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