Abstract
The surface tension of PO added sodium poly(oxyethylene(EO), oxyisopropylene(PO)) dodecyl ether sulfate firstly were slightly lower than EO added sulfate in the concentration range of $10^{-6}{\sim}10^{-3}mol/{\ell}$. And they had lower critical micelle concentration ($10^{-4}{\sim}9{\times}10^{-5}mol/{\ell}$) than general anionic surfactants. The adsorptivity ($2.2{\times}10^{-10}mol/cm^2$) of sodium $(PO)_{10}(EO)_5$ dodecyl ether(compound of PO addition firstly) calculated by Gibbs' adsorption isotherm were higher than that of sodium $(EO)_{10}(PO)_5$, dodecyl ether(compound of EO addition firstly), but were lower than that of sodium dodecyl sulfate (${\Gamma}=3.2{\times}10^{-10}mol/cm^2$). These could be understood that the adsorption areas of compounds were very large because of their high molecular weight. Moreover, PO compounds showed better properties than EO compounds in foamability, emulsifying power for organics (n-hexane, benzene), detergency for the lard, tallow oil mixture and dispersability for iron oxide. It was interpreted in terms of surface properties of the PO compounds. These showed that the interfacial activity become higher when hydrophilic and hydrophobic portion existed in aggoromerated state respectively. The test results of emulsifying power for organics (n-hexane, benzene) showed better for benzene than n-hexane. Eight kinds of sodium (EO, PO) dodecyl ether derivatives showed irregular dispersibilities for polar iron oxide in water dispersed media.
$10^{-6}{\sim}10^{-3}mol/{\ell}$ 농도범위에서 PO가 먼저 부가된 sodium poly(oxyethylene(EO), oxyisopropylene(PO)) dodecyl ether sulfates의 표면장력은 EO가 부가된 화합물보다 낮게 나왔다. 그리고 대체적으로 일반적인 음이온성계면활성제보다도 낮게 나왔다. PO가 먼저 부가된 화합물에 대하여 Gibbs' 흡착등온선으로 계산한 흡착능(${\Gamma}=2.2{\times}10^{-10}mol/cm^2$)은 EO가 부가된 화합물보다는 높지만 sodium dodecyl ether sulfate(${\Gamma}=3.2{\times}10^{-10}mol/cm^2$)보다는 낮다. 이러한 현상은 PO가 부가된 화합물의 분자량이 크기 때문으로 사료된다. 기포력, n-hexane과 benzene에 대한 유화력, 돼지기름과 소기름에 대한 세정력 그리고 산화철에 대한 분산성은 PO 화합물이 EO 화합물보다 우수하게 나타났다. 이러한 현상들은 친수성과 소수성 부분이 각각 따로 따로 존재할 때 계면활성이 높음을 의미한다. 수계에서 n-hexane과 benzene에 대한 유화력 측정결과는 n-hexane보다 benzene에 대하여 높게 나왔으며, 불규칙적인 분산특성을 나타내었다.
