双子季铵盐改善聚羧酸减水剂对黏土的敏感性能

针对黏土对含聚羧酸系减水剂水泥浆体流变性能的负面影响,以三乙胺分别与1,4-二溴丁烷、1,5-二溴戊烷和对二溴苄反应合成了3种阳离子双子季铵盐(分别标记为KN1,KN2和KN3),并将其与聚羧酸盐减水剂RS-1复配.KN1,KN2和KN3的分子结构采用傅里叶红外光谱(FTIR)和核磁共振氢谱(~1H NMR)测试和证实.双子季铵盐和减水剂复配体系的抗泥效果通过测定水泥净浆流动度进行评价.同时,综合运用X射线衍射(XRD)、水接触角和总有机碳(TOC)等表征手段,考察了双子季铵盐和减水剂复配体系对水泥分散、亲疏水性和吸附性能的影响.结果表明:当蒙脱土的含量为3%(质量分数)时,KN1,KN2和KN3均可显著提高水泥净浆的流动度,并能保持良好的稳定性,且KN3表现出更优异的抗泥性能.

Improvement of Clay Sensitivity of Polycarboxylate Superplasticizer by Gemini Quaternary Ammonium Salt

For the negative influence of clay on the rheological properties of cement slurry containing polycarboxylate superplasticizer,three cationic gemini quaternary ammonium were synthesized by triethylamine with 1,4 dibromopropane,1,5 dibromopentane and p dibromobenzyl respectively through quaternization. The corresponding products were labeled as KN1, KN2, and KN3, respectively. Then they were compounded with polycarboxylate water reducing agent RS 1 to reduce the clay sensitivity of the water reducer. The molecular structures of KN1, KN2 and KN3 were characterized by FTIR and 1H NMR. The gemini quaternary ammonium salt properties of the compounded system were evaluated by measuring fluidity of cement paste. Meanwhile, the dispersion, hydrophobicity and adsorption properties of the compounded system were investigated by XRD, water contact angle and total organic carbon(TOC). The results indicate that when the content of montmorillonite is 3%(by mass), KN1, KN2 and KN3 can significantly improve the fluidity of cement paste. Among those, KN3shows the best anti clay performance.