不同分子结构减水剂与黏土矿物作用机理研究

Research on action mechanism between different structures of water reducing agents with clay minerals

研究了4种不同分子结构的聚羧酸减水剂与黏土矿物海泡石的作用机理。结果表明,海泡石会造成掺加聚羧酸减水剂水泥浆流动度降低;TOC的分析结果表明,海泡石对4种减水剂都有较强的吸附性,且吸附量随减水剂溶液浓度的增大而增大;XRD测试结果表明,4种分子结构减水剂均不会与海泡石发生插层反应。减水剂分散效果的降低主要是由于海泡石对其表面的吸附作用所致,减水剂分子中羧酸盐基含量越高,海泡石对其吸附量就越大;另外,减水剂分子中含有双键等不对称结构,可能会加强海泡石矿物对减水剂的吸附效果。

The interaction mechanism between four kinds of polycarboxylate superplastieizers with different structures and clay mineral sepiolite was discussed. The results show that sepiolite tends to reduce the fluidity of cement paste. The results of TOC suggest that sepiolite has strong adsorption on four kinds of polycarboxylate superplasticizers,and adsorption amount is increased with the increasing concentration of superplasticizer solution. The results of XRD show that four kinds of polycarboxylate superplasticizers with different structures can not he intercalated into the interlayer of sepiolite. The decrease of the dispersion is mainly due to the adsorption action of sepiolite on superplasticizers. More content of density of carhoxylate group in side chain leads to greater adsorption amount of sepiolite. In addition,asymmetric structure,such as double bond,may enhance the adsorbing ability of superplasticizer.