摘要
以1,4-对二氯苄为连接基团,分别以三乙胺和N,N-二甲基乙醇胺为头基,合成了具有不同端基的双子季铵盐(标记为KNJ-1和KNJ-2)。将其作为抗泥剂与聚羧酸盐减水剂复配,以改善蒙脱土对减水剂的负面效应,探究了端羟基的引入对抗泥效果的影响。通过FTIR和~1HNMR对其进行了结构表征。净浆流动实验考察抗泥剂的掺量对流动度的影响,并结合XRD、XPS和Zeta电位分析双子季铵盐与蒙脱土的作用机理。实验结果表明:与未掺抗泥剂的水泥相比,加入质量分数0.3‰KNJ-2使水泥初始净浆流动度提高了35 mm,2 h后流动度提高了175 mm,表现出显著的抗泥效果。XRD和XPS结果表明,KNJ-2在蒙脱土的表面和层间吸附均优于KNJ-1;Zeta电位结果显示,KNJ-2的加入使蒙脱土表面电位从初始的–15.67 mV上升到–0.15 mV。表明羟基可通过氢键作用优先吸附在蒙脱土的表面和层间,占据大量活性位点,减少了对聚羧酸盐减水剂的吸附,保障了减水剂的高效分散能力,从而达到对蒙脱土负面影响抑制的效果。
Two Gemini quaternary ammonium salts were synthesized by using 1,4-p-dichlorobenzyl as linking group and N,N-dimethylethanolamine(or triethylamine)as head group(labeled as KNJ-1 and KNJ-2).They were used as anti-clay agent and compounded with polycarboxylate superplasticizer to weaken the negative effect of the clay on the polycarboxylate superplasticizers.The effect of the terminal hydroxyl group on the clay effect was investigated.Their structures were characterized by FTIR and^1HNMR.The effect of anti-clay agent on the fluidity of cement paste was evaluated.The mechanism of action between quaternary ammonium salt and montmorillonite was analyzed by X-ray photoelectron spectroscopy,X-ray diffraction and Zeta potential measurement.The results showed that compared with that of the cement without anti-clay agent,the addition of 0.3‰mass fraction of KNJ-2 increased the initial fluidity by 35 mm,and the fluidity increased by 175 mm after 2 hours,showing that KNJ-2 possessed a prominent anti-clay advantage.XRD and XPS results revealed that the adsorption of KNJ-2 on the surface and interlayers of montmorillonite was superior to that of KNJ-1.Zeta potential of montmorillonite was increased from the initial–15.67 m V to–0.15 m V after the introduction of KNJ-2,It was found that hydroxyl group can preferentially adsorb on the surface and interlayers of montmorillonite byhydrogen bonds,occupying a large number of active sites,reducing the adsorption of polycarboxylate superplasticizer,guaranteeing the efficient dispersing ability of the superplasticizer,and thereby inhibiting the negative effects of montmorillonite.
作者
张雪
张光华
蒋婷
王爽
张策
崔鸿跃
Zhang Xue;Zhang Guanghua;Jiang Ting;Wang Shuang;Zhang Ce;Cui Hongyue(Shaanxi Key Laboratory of Chemical Additives for Industry,Shaanxi University of Science&Technology,Xi'an 710021,Shaanxi,China;Shanxi Yuncheng Hongxiang Building Materials Co.,Ltd.,Yuncheng 044000,Shanxi,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2020年第1期189-194,共6页
Fine Chemicals
基金
国家自然科学基金(21176148)
陕西省教育厅重点实验室开放基金(14JS016).
关键词
双子季铵盐
聚羧酸盐减水剂
黏土
吸附
建筑用化学品
Gemini quaternary ammonium salt
polycarboxylate superplasticizers
clay
adsorption
building chemicals
