GPC测聚羧酸减水剂吸附量对水泥助磨剂的抗干扰作用

GPC's anti-interference effect against cement grinding aids when detecting adsorption of polycarboxylate superplasticizer

考察了三乙醇胺、乙酸钠、硬脂酸、木质素磺酸钠等助磨剂对凝胶渗透色谱法(GPC)和紫外-可见分光光度法(UV)测定聚羧酸减水剂(PCE)吸附量的干扰问题。结果表明,用GPC法测定PCE的吸附量,GPC色谱柱可有效分离PCE和助磨剂,助磨剂对PCE浓度及其吸附量的测定结果不产生明显影响,其干扰系数接近于0。而用UV法测定PCE的吸附量,助磨剂的紫外吸收会对PCE浓度的测定结果产生干扰,从而使吸附量计算结果偏小,甚至出现负值。不同助磨剂对UV法的干扰系数分别为:木质素磺酸钠为8.30,三乙醇胺为4.84,硬脂酸为0.81,乙酸钠为0.63。

When the gel permeation chromatography（ GPC） method and ultraviolet and visible spectrophotometer（ UV） method are used to detect absorption capacity of polycarboxylate superplasticizer（ PCE）,the interference effects generated by grinding aids such as triethanolamine,sodium acetate,stearic acid and sodium lignosulphonate are studied respectively.The result shows that PCE and grinding aids can be separated effectively by GPC chromatographic column when GPC method is used to determine the adsorption capacity of PCE.Moreover,grinding aids have no significant impact on the detection results of PCE concentration and its adsorption capacity,with the interference coefficient close to zero.However,the determination of PCE concentration is influenced by grinding aids＇ absorption against ultraviolet when the UV method used to determine the adsorption capacity of PCE.Thus,the adsorption capacity calculation results are smaller than normal,or even negative. The interference coefficients of sodium lignosulphonate,triethanolamine,stearic acid and sodium acetate are 8. 30,4. 84,0. 81,0. 63,respectively.