聚氧乙烯烷基酚醚羧甲基钠盐的提纯及表面活性

PURIFICATION AND SURFACE PROPERTIES OF SODIUM POLY(OXYETHYLENE)NONYLPHENYLENE ETHER CARBOXYMETHYLATES

用硝酸银作沉淀剂，采用沉淀法提纯了标称氧乙烯（ＥＯ）数分别为２和４的聚氧乙烯烷基酚醚羧甲基钠盐，纯度在９９．８％以上。测定了不同温度和离子强度下的表面张力，由热力学关系计算出其表面性质和胶团化及表面吸附过程的标准热力学函数。结果表明，标称ＥＯ数由２增至４时，分子的最小截面积增加，反离子结合度减小，表面张力降低能力则下降很小。加入氯化钠，可使表面活性分子的最小截面积明显减小，却对表面张力降低能力影响甚微。

A precipitation method was employed to purify sodium poly (oxyethylene)nonylphenylene ether carboxymethylates with 2 and 4 of EO(ethylene oxide),taking silvernitrate as precipitation agent.Their purities were both over 99.8%,and the distribution ofEO was determined by high performance liquid chromatograph.Surface tension investigated atvarious temperatures and inoic strengths by drop volume method was used to calculate thesurface and thermodynamic properties. It was found that with the increase of EO from 2 to4,minimum area per molecule at the aqueous solution/air surface(A(min))increased,while thedegree of counter ion binding (K0)decreased, and the effectiveness of surface tensionreduction(π(mic))decreased slightly, and the addition of NaCl resulted in a great decrease ofA(min)and only had a light effect on π(CMC).