Abstract A novel polycarboxylate superplasticizer (PCE) with a long polyoxyethylene (PEO) chain and a terminal carboxylic group was synthesized from a modified polyether (SAE-IPEG) to increase its performance in cement. The molecular structure of the PCE was characterized by infrared spectroscopy and 1H nuclear magnetic resonance (NMR) spectroscopy. The performance of synthesized PCE in cement was studied in the absence and the presence of montmorillonite (Mmt) clay. It was found that the PCE disperses in cement uniformly without aggregation, which is different significantly from the conventional PCEs. Adsorption measurements and X-ray diffraction analysis revealed that the synthesized PCE only interacted with Mmt via surface adsorption, whereas the conventional PCEs interact with the clay through the surface adsorption and the chemical intercalation. Such dramatic change could be ascribed to the introduction of an electronegative carboxylic acid group as a terminal group into the long polyoxyethylene chain of PCE, which reduced the adsorption and enhanced tolerance of PCE on Mmt.

中文翻译：

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聚羧酸盐作为水泥中蒙脱石粘土的减水剂：吸附和耐受性研究

摘要 以改性聚醚（SAE-IPEG）为原料合成了一种具有长聚氧乙烯（PEO）链和末端羧基的新型聚羧酸减水剂（PCE），以提高其在水泥中的性能。PCE 的分子结构通过红外光谱和 1 H 核磁共振 (NMR) 光谱表征。在不存在和存在蒙脱石 (Mmt) 粘土的情况下研究了合成 PCE 在水泥中的性能。结果表明，四氯乙烯在水泥中分散均匀，没有聚集，这与传统的四氯乙烯有显着差异。吸附测量和 X 射线衍射分析表明，合成的 PCE 仅通过表面吸附与 Mmt 相互作用，而传统的 PCE 通过表面吸附和化学插层与粘土相互作用。这种戏剧性的变化可归因于在 PCE 的长聚氧乙烯链中引入了一个带电负性的羧酸基团作为末端基团，这减少了 PCE 对 Mmt 的吸附和增强的耐受性。