聚羧酸系高性能减水剂的结构表征与测试方法

摘要

A PC-CW type of polycarboxylate superplasticizer (PCE) was synthetized under the process at ambient temperature,the monomer ratio for the backbone was determined by H-NMR spectra. IN addition,the functional groups in the chemical structure of the superplasticiser were characterized by FTIR and the extent of the reaction was estimated. Molecular weight of PC-CW and PC-1 synthesized at elevated temperature were measured,the results showed that PC-CW has a narrower molecular weight distribution and a more homogeneous molecular weight. The Zeta potential results revealed that with increasing dosage,the adsorption of the PCE on cement increased,and then decreased,which showed different adsorption characteristics. PCE delayed the hydration heat of the cement,and the exothermic trend of cement hydration of PC-CW and PC-1 was similar.%常温工艺合成一种聚羧酸系高性能减水剂 PC-CW，通过氢核磁共振谱测定聚合物主链单体比例。对其进行红外光谱分析，检测主体聚合物的分子结构中的各官能团，推断反应进行的程度。测定 PC-CW及高温工艺合成样品 PC-1的分子量，结果显示 PC-CW具有更窄的分子量分布，聚合物分子量更为均一。两种减水剂的 Zeta电位测试数据显示水泥对 PCE的吸附随掺量的增加表现出先增大后减小的趋势，吸附量则呈现出不同的吸附特征。PCE可以推迟水泥的水化放热，掺加 PC-CW与 PC-1的水泥水化放热趋势基本相同。