Performances and working mechanism of a novel polycarboxylate superplasticizer synthesized through changing molecular topological structure
Performances and working mechanism of a novel polycarboxylate superplasticizer synthesized through changing molecular topological structure
复制标题
改变分子拓扑结构合成的新型聚羧酸高效减水剂的性能及作用机理
DOI：
10.1016/j.jcis.2017.05.025
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发表时间：
2017-10-15
影响因子：
9.9
通讯作者：
Li, Huiqun
中科院分区：
文献类型：
--
作者：
Liu, Xiao;Guan, Jianan;Li, Huiqun
采用简单的两步法合成了一种新型星形聚羧酸酯高效减水剂（SPCE）。H-1核磁共振（H-1 NMR）和红外光谱（IR）测量用于结构表征。设计合成了具有相同分子量的SPCE和梳状聚羧酸酯高效减水剂（CPCE）。含SPCE的水泥浆体具有较好的流动性、保流性和减水性，PCE的饱和掺量降低25%，凝结时间延长10%，水化热较低，水化热演化较迟，早期水化产物较少。进一步研究了SPCE和CPCE在水泥浆体中的吸附行为和zeta电位，从理论上解释了SPCE的工作机理。有趣的是，将拓扑结构从梳状改变为星形，可以实现色散效果的优化，进一步提高工作效率。本研究的目的是为合成结构新颖的高效减水剂提供一条新的途径，实现高效减水剂结构的化学多样性，并验证优化分子形状的贡献。该新型高效减水剂可作为新型水泥基材料的流变改性剂。(C) 2017爱思唯尔公司版权所有。
A novel star-shaped polycarboxylate superplasticizer (SPCE) was synthesized through a simple two-step method. H-1 Nuclear Magnetic Resonance (H-1 NMR) and Infrared Spectroscopy (IR) measurements were used for structural characterization. SPCE and comb-shaped polycarboxylate superplasticizer (CPCE) with same molecular weights were designed and synthesized. The cement paste containing SPCE exhibited better fluidity, fluidity retention, water reduction, 25% lower saturated dosage of PCE, 10% longer setting time, lower hydration heat, more delayed hydration heat evolution and lower amount of hydration products at early ages. Furthermore, the adsorption behavior of SPCE and CPCE in cement pastes and the zeta potential were investigated, and then the working mechanism of SPCE was theoretically explained. It is interesting that changing topological structure from comb-shape to star-shape can achieve the optimization of dispersion effect, and further improve the working effectiveness. The aims of this study are to provide a new avenue to synthesize superplasticizer with novel structure achieving the chemical diversity of superplasticizer structure, and to verify the contribution of optimizing molecular shape. This new type of superplasticizer can be used as a rheology modifying agent in fresh cement-based materials. (C) 2017 Elsevier Inc. All rights reserved.