不同分子量聚羧酸减水剂的结构分析及性能研究

Structural Analysis and Properties Study of Polycarboxylate Water Reducers with Different Molecular Weights

本文使用核磁氢谱对PC、PC30000、PC50000和PC70000的分子结构进行剖析,并结合水泥净浆流动度结果,揭示了不同相对分子质量范围的PC组分分散性能各异的结构本质。试验表明:随着聚羧酸减水剂相对分子量的提高,聚羧酸减水剂分子结构中的酸醚比逐渐下降;随着聚羧酸减水剂相对分子量的提高,其初始净浆流动度逐渐下降,净浆流动度经时损失变小。因此,得出以下结论:聚羧酸减水剂组分的分子量越高,其分子结构中的酸醚比越低,初始分散性能也越低,保坍性能越高。

The molecular structure of PC ( Polycarboxylate), PC30000, PC50000 and PC70000 is analyzed by nuclear magnetic resonance spectroscopy. Combined with the results of cement paste fluidity, the structure natureis revealednamely the dispersion performance of PC components with different relative molecular mass range is different.The experiment shows that the acid -ether ratio in the molecular structure of the polycarboxylate water reducers decreases with the increase of the relative molecular weight of polycarboxylate water reducers. With the increase of the relative molecular weight of polycarboxylate water reducers, the initial slurry fluidity gradually decreases, and the slurry fluidity losses with time.Therefore, it is concluded that the higher the molecular weight of the polycarboxylic water reducers, the lower the acid-ether ratio in the molecular structure, the lower the initial dispersion property, while the higher the slump loss resistant property.