阴离子表面活性剂钙皂分散力测定方法——酸滴定法的改进

An improvement of anionic surfactant-determination of the power to disperse calcium soap-acidimetric method

通过考察油酸钙沉淀溶液中残留的油酸根离子,确定了油酸钙沉淀稳定(0.5～1 g/L的油酸钙沉淀)时溶液的水硬度应≥132 mg/L(以Ca2+计);测试了0.01%～0.4%的直链十二烷基苯磺酸钠(LAS)与十二烷基硫酸钠(SDS)溶液在硬水中的沉淀性能,发现在钙离子质量浓度≤150 mg/L的硬水中这2种表面活性剂不会出现沉淀;表面活性剂钙皂分散力优化测试条件为:钙离子150 mg/L的硬水,0.5 g/L油酸钙,40℃分散1 h,样品取过快速滤纸的分散滤液;给出了常用阴离子表面活性剂在该优化条件下的钙皂分散力.

The water hardness of precipitation of calcium oleate was determined more than 132 mg/L （ac cording to Ca2＋） through the investigation of the residue oleate in calcium oleate （0.5N1 g/L） when the calcium oleate was stable. The precipitation phenomena of 0.01%-0.4% linear alkyl benzene sulfonate （LAS） and sodi um dodecyl sulfate （SDS） in hard water were investigated. It was found that both LAS and SDS did not precipi tate when the concentration of Ca2 in hard water was lower than 150 mg/L. The optimum conditions of determining the power of the anionic surfactant to disperse calcium soap were obtained： in 150 mg/L of Ca2＋ hard water, the concentration of calcium oleate was 0.5 g/L, dispersed at 40 ℃for 1 h. The sample was taken the dispersion filter liquor after filtering by the quick speed of filter paper. The data of power of common used anionic surfactants to disperse calcium soap were provided under the optimum condition.